Berkeley City Council
February 11, 2025

Tuesday, February 11, 2025 AGENDA Page 1

P R O C L AM AT I O N

C AL L I N G A S P E C I AL M E E T I N G O F T H E

B E R K E L E Y C I T Y C O U N C I L
In accordance with the authority in me vested, I do hereby call the Berkeley City Council in special session as follows:

Tuesday, February 11, 2025
4:00 PM
SCHOOL DISTRICT BOARD ROOM - 1231 ADDISON STREET, BERKELEY, CA 94702

ADENA ISHII, MAYOR
Councilmembers:

DISTRICT 1 – RASHI KESARWANI DISTRICT 5 – SHOSHANA O’KEEFE DISTRICT 2 – TERRY TAPLIN DISTRICT 6 – BRENT BLACKABY
DISTRICT 3 – BEN BARTLETT DISTRICT 7 – CECILIA LUNAPARRA DISTRICT 4 – IGOR TREGUB DISTRICT 8 – MARK HUMBERT
This meeting will be conducted in a hybrid model with both in -person attendance and virtual participation. Live captioned broadcasts of Council meetings are available on B -TV (Channel 33) and via internet video stream at http://berkeley.granicus.com/MediaPlayer.php?publish_id=1244. All Council meetings are recorded.

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This meeting will be conducted in accordance with the Brown Act, Government Code Section 54953. Any member of the public may attend this meeting, however, if you are feeling sick, please do not attend the meeting in person.

The City Council may take action related to any subject listed on the Agenda.

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The above contribution disclosures and restrictions do not apply when the proceeding is competitively bid, or involves a personnel or labor contract. For more information, see Government Code Section 84308.

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Preliminary Matters
Roll Call:

Action Calendar
The public may comment on each item listed on the agenda for action. For items moved to the Action Calendar from the Consent Calendar or Information Calendar, persons who spoke on the item during the Consent Calendar public comment period may speak again during the Action Calendar public comment period on the item
The Presiding Officer will request that persons wishing to speak line up at the podium, or use the "raise hand" function in Zoom, to determine the number of persons interested in speaking at that time. If ten or fewer persons are interested in speaking on an individual agenda item, each speaker may speak for two minutes. If there are more than ten persons interested in speaking, the Presiding Officer may limit the public comment for all speakers to one minute per speaker. Speakers are permitted to yield the ir time to one other speaker, however no one speaker shall have more than four minutes. The Presiding Officer may, with the consent of persons representing both sides of an issue, allocate a block of time to each side to present their issue.

Action items may be reordered at the discretion of the Chair with the consent of Council.

The Presiding Officer may open and close an additional comment period for Action items on this agenda (excluding any public hearings, appeals, and/or quasi-judicial matters), at the start of the Action Calendar.

Those who speak on an item during this comment period may not speak a second time when the item is taken up by Council.

Action Calendar – New Business
1a. Effective Mitigations for Berkeley’s Ember Resilience (EMBER): Fire Code Amendments
From: City Manager
Recommendation: Provide feedback and direction on next steps for consideration or implementation of the following three proposals:

Proposal 1: Create a Berkeley Fire Zone 4 within the Fire Code to include – at minimum - the areas between Wildcat Canyon Rd. to the east, Grizzly Peak Blvd to the west, and the Berkeley City Limits to the south and north; Proposal 2: Repeal the Berkeley Fire Code (BMC Chapter 19.48) and reenact BMC Chapter 19.48 to include an ember resistant “Zone Zero” and other defensible space best practices (Attachment 1) and schedule a Public Hearing for the first reading on March 25, 2025 pursuant to state law; and
Proposal 3: Research the Quantifying the Negative (QTN) approach, a methodology that measures the economic value of fire services by quantifying the losses it prevents and how it may be applied to quantify the value of the EMBER initiative, which staff would bring back to City Council no later than December 2025.

Financial Implications: See rep ort
Contact: David Sprague, Fire, (510) 981-3473

Action Calendar – New Business

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1b. Effective Mitigations for Berkeley’s Ember Resilience (EMBER): Building Code Amendments
From: City Manager
Recommendation: Staff will return to Council by the end of 2025 with a resolution for the triannual adoption of the existing Berkeley Building, Historical and Fire Codes that will be applicable to Berkeley Fire Zone 3 and 4. These amendments to the 2025 California Building Standards will strengthen defenses against ignition of structures from embers, radiant heat and direct flame impingement during wildfire. Staff seeks Council’s input on this proposal and plan to return to Council at the end of 2025 with a resolution proposed for adoption that incorporates the Council’s feedback.

The amendments may include but are not limited to requiring Class A roofs during partial replacement of non-compliant roof and roof structures, requiring replacement of combustible siding with California Building Code (CBC) Chapter 7A compliant siding during partial replacements, installation of metal gutters and screens, installation of Chapter 7A compliant vents or vent screens, replacement of combustible decks and fences with Chapter 7A compliant materials and design during partial replacement, and six inches of vertical separation measured from the ground to any combustible siding.

Because of the fiscal impact that some of this work will have for homeowners, staff plans to investigate Federal, State or Municipal programs that would provide incentives and loans for improvements to existing non-compliant homes that focus on the highest priority items, such as roof material, siding, decks, ember resistant vents, and a 6” vertical separation between the siding and the ground at the base of a home near the foundation.

Financial Implications: See report
Contact: David Sprague, Fire, (510) 981-3473

1c. Effective Mitigations for Berkeley’s Ember Resilience (EMBER): Leave Early and Fire Department Staffing
From: City Manager
Recommendation: Provide insights, feedback and input on two proposals below as well as desired next steps:

1. Proposal 1: Evaluate the thresholds for the City’s Extreme Fire Weather designation and the National Oceanic and Atmospheric Administration’s (NOAA) Particularly Dangerous Situation (PDS) designation, considering how use of each would impact the City’s “Leave Early” concept. Staff propose returning to City Council no later than the 2nd week of May 2025; and

2. Proposal 2: Affirm City Council support for Fire Department staffing recommendations 1, 5, 6, and 10 from the Fire Department Standards of Coverage and Community Risk Assessment (SOC) study.

Financial Implications: See report
Contact: David Sprague, Fire, (510) 981-3473

Action Calendar – New Business

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1d. Request Inter-Departmental Collaboration and Implementation of Safe Passages
From: Councilmember Blackaby (Author), Councilmember Humbert (Co- Sponsor), Councilmember O'Keefe (Co-Sponsor)
Recommendation: Refer to the City Manager to direct the Departments of Public Works, Police and Fire to work collaboratively to implement Safe Passages Program – EMBER Initiative Phase 1 and 2 and report back to City Council on progress no later than the 2nd week of May 2025. This program will further facilitate responder ingress and community evacuation during wildfires by developing a plan to create and enforce no-parking zones in addition to existing 24/7/365 red curbs and no- parking zones during extreme fire weather conditions and/or the broader fire season.

Financial Implications: See report
Contact: Brent Blackaby, Councilmember, District 6, (510) 981-7160

Adjournment
I hereby request that the City Clerk of the City of Berkeley cause personal notice to be given to each member of the Berkeley City Council on the time and place of said meeting, forthwith.

IN WITNESS WHEREOF, I have hereunto set my hand and caused the official seal of the City of Berkeley to be affixed on this 6th of February, 2025.

/s/ Adena Ishii, Mayor
Public Notice – this Proclamation serves as the official agenda for this meeting.

ATTEST:

Date: February 6, 2025
Mark Numainville, City Clerk

NOTICE CONCERNING YOUR LEGAL RIGHTS : If you object to a decision by the City Council to approve or deny a use permit or variance for a project the following requirements and restrictions apply:
1) No lawsuit challenging a City decision to deny (Code Civ. Proc. §1094.6(b)) or approve (Gov. Code 65009(c)(5)) a use permit or variance may be filed more than 90 days after the date the Notice of Decision of the action of the City Council is mailed. Any lawsuit not filed within that 90 -day period will be barred. 2) In any lawsuit that may be filed against a City Council decision to approve or deny a use permit or variance, the issues and evidence will be limited to those raised by you or someone else, orally or in writing, at a public hearing or prior to the close of the last public hearing on the project.

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Agendas, agenda reports, and revised/supplemental material may be accessed via the online agenda for this meeting at:
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ACTION CALENDAR
February 11, 2025
To: Honorable Mayor and Members of the City Council
From: Paul Buddenhagen, City Manager
Submitted by: David Sprague, Fire Chief
Subject: Effective Mitigations for Berkeley’s Ember Resilience (EMBER): Fire Code Amendments

RECOMMENDATION
Provide feedback and direction on next steps for consideration or implementation of the following three proposals:

Proposal 1: Create a Berkeley Fire Zone 4 within the Fire Code to include – at minimum - the areas between Wildcat Canyon Rd. to the east, Grizzly Peak Blvd to the west, and the Berkeley City Limits to the south and north;
Proposal 2: Repeal the Berkeley Fire Code (BMC Chapter 19.48) and reenact BMC Chapter 19.48 to include an ember resistant “Zone Zero” and other defensible space best practices (Attachment 1) and schedule a Public Hearing for the first reading on March 25, 2025 pursuant to state law; and
Proposal 3: Research the Quantifying the Negative (QTN) approach, a methodology that measures the economic value of fire services by quantifying the losses it prevents and how it may be applied to quantify the value of the EMBER initiative, which staff would bring back to City Council no later than December 2025.

SUMMARY
Fire is a historical part of our landscape since long before modern city planning or residential settlement of the Berkeley Hills. Eliminating the likelihood of fire has been proven both inadequate and ill-informed. Post-incident analysis and laboratory testing suggest that we should be focusing our efforts on the threatened structures instead.

This report provides evidence that informs the most up to date recommendations that protect homes from wildfire and urban conflagration. Best practice requires removing flammable materials and maintaining vegetation to minimize wildfire exposure, particularly within the critical Ember Resistant Zone (Zone 0) and surrounding Home Ignition Zones 1 and 2. These measures require elimination of all combustible materials from within 5 feet of a structure, including vegetation and accessories.

These mitigations work best when they are taken on by a contiguous group of homes.

To be effective, the Berkeley Fire department suggests that we focus inspection efforts

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on Panoramic Hill, and residences east of Grizzly Peak Blvd. Once compliance is gained to this new standard, other areas would be systematically included until all of the Berkeley hills within the Very high Fire Hazard Severity Zone is included.

As a way to validate and support the work, the department would also use a peer- reviewed approach called Quantifying the Negative to help justify the work and explain how the efforts of residents are concretely helping the community.

FISCAL IMPACTS OF RECOMMENDATION
Substantial staff time is required to update and implement Fire Code modifications. The Department will work within its established budget to implement what recommendations it can. The Department will return to Council with grant applications, creative funding strategies, or budget requests if alternate funding strategies are not realized. At this time, the EMBER package creates no new impacts to the General Fund

CURRENT SITUATION AND ITS EFFECTS
The fire tragedy suffered by the Los Angeles area is the most recent demonstration that wildfire is a recurring feature of our landscape, even more so as climate change results in more frequent extreme weather events. Maintaining the status quo in communities with exposure to wildfire will inevitably result in similar, disastrous outcomes. Below is a partial list of recent wildfires that remind us of the potential for destruction of property and loss of life that is possible in Berkeley. We have the opportunity and agency to take actions to reduce the probability of wildfire loss in our community.

Fire Name County Acres Date Structures Deaths
Lahaina Maui 2,170 08/2023 2,200 102
Camp Butte 153,336 11/2018 18,804 86
Tunnel Alameda 1,600 10/1991 2,900 29
Thomas Ventura, Santa
Barbara 281,893 12/2017 1,063 23
Tubbs Napa, Sonoma 36,807 10/2017 5,643 22
Eaton Los Angeles 14,117 01/2025 7,000+ 16
North Complex Plumas, Butte 318,935 08/2020 2,352 15
Cedar San Diego 273,246 10/2003 2,820 15
Palisades Los Angeles 23,713 01/2025 6,000+ 11
These wildfires transitioned into areas of dense structures due to key vulnerabilities that enabled their devastating fire behavior. Common factors included widespread pre-2008 construction which lacks modern fire-resistant standards as found in the California Building Code, lack of home hardening measures to retrofit these vulnerable structures;

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delays in statewide adoption of ember resistant zone “Zone 0”, and the need for more stringent and focused fire prevention measures in vulnerable neighborhoods particularly at points where wildfire pathways enter communities. These factors have, again and again, contributed to vegetative wildfires penetrating communities, igniting structures, and transitioning into a wind driven structure-to-structure conflagration1, which overwhelm available firefighting resources. We have a moral imperative to shift our focus away from only the response, as evidenced by the recurring outcome above. It is time to voraciously engage with what we know will save homes and lives.

Adoption of unadulterated, scientifically validated mitigation measures proven to reduce the vulnerability of a neighborhood from ignition during a wildfire offers the best chance of minimizing the probability of vegetative to urban fire transition. This memo outlines a trio of policies aimed at achieving a community that is safer from wildfire. These policies are structured around proactive measures to be implemented at the demonstrated most effective point -- before a fire occurs.

BACKGROUND AND DISCUSSION
The City of Berkeley has climatic, geological, and topographical conditions, which require local amendments to mitigate potential hazards, and to reduce loss of life caused by fires or natural disasters. To address local fire and life safety impacts, the City of Berkeley has adopted local amendments to address local conditions which make CFC requirements inadequate. Without the adoption of local amendments, needed fire and life safety enhancements cannot be enforced.

Fire History in Berkeley and Around the East Bay
Berkeley and the East Bay Hills have a cyclical relationship with wildfire. Before European colonizers arrived, California experienced many small, frequent fires2. These low-intensity fires benefitted the landscape because they cleaned out underbrush — which otherwise serve as fuel for larger fires — and helped native species regenerate.

Along with other wildfire prone regions, the East Bay has suffered from the exclusion of traditional wildfire patterns from the landscape for over 150 years. This has resulted in a triad of risk: an abundance of vegetative fuel, a dense urban development of vulnerable homes, and an undersized network of roadways relative to the volume of vehicles. This is not new information, a 1974 report prepared for the city regarding the fire risk for Panoramic Hill states the following:
1 CAL FIRE TV. (2025, January 26). CAL FIRE: When hones fall like dominos. [Video]. YouTube. https://youtu.be/LfTVKfcBvEk?si=q0MpxZ9w1gNFr3yz
2 Hao, C., (2022, October 15). This one fact will completely change how you think about California wildfires. The San Francisco Chronicle. https://www.sfchronicle.com/projects/2022/california-wildfire- history/

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Panoramic Hill originally was composed of grasslands and brush on the ridges with dense tree and other growth along the creeks. However, man has altered the environment greatly.... Within the neighborhood, residents have planted dense stands of trees and other vegetation, such that the homes look as though they had been built within the forest.3 The suppression of natural fire patterns to protect a now populated topography has not eliminated the risk but rather held it back as the fuel load – both vegetative and built- has increased. The effects of climate change have exacerbated the historical problem, compressing the rainy season and increasing the drying of fuels. This combination creates a fire problem that is now demonstrably more destructive when it overwhelms suppression efforts. The immediate Berkeley area has experienced a significant wildfire on average every 20 years4 since 1905, with 2024 marking the 33rd year since the last major fire in the area. Since 2020, the city has been moving with great haste to revisit our historical thinking to research and bring best practices in wildfire planning, prevention and response to Berkeley.

Progress thus far
The Berkeley City Council unanimously declared wildfire prevention and safety a top priority on October 15, 20195. This declaration helped establish this issue as one of the key priorities of the 2020 Measure FF tax.

Since the passage of Measure FF, the Department has created and funded a Wildland Urban Interface (WUI) Division. The WUI Division has annually inspected all private property in Fire Zones 2 and 3. Thus far, that has resulted in 21,856 inspections. These have uncovered 11,042 violations, of which 9,972 have been resolved.

The WUI Division also provides a number of free services to the community. In 2024 crews removed 3234 cubic yards of green waste from private property using these services. A home hardening mesh program has also been launched which provides CBC Chapter 7A compliant ember resistant mesh to homes in the highest hazard area, including the current Berkeley Fire Zone 3, proposed Berkeley Fire Zone 4, and both recognized and budding FireWise communities. That program has thus far provided material to 50 homes and continues to expand as material and staff time allow. Crews are about to embark on a vegetation (fuel) mitigation project along common public rights of way and critical evacuation routes and in 2025 a $1 million CAL FIRE grant will be 3 Berkeley Planning Department, June 1974. Panoramic Hill Area Development and Environmental Resources Study., p. 38.
4 East Bay Parks (retrieved February 1, 2025).
https://www.ebparks.org/sites/default/files/history_all_fires.pdf 5 Berkeley City Council Meeting 10/15/2019

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leveraged to assist low income and disabled homeowners with vegetation management on private property.

A Focused and Phased Approach
The effectiveness of the City’s Defensible Space Inspection program is reduced by the size of the impacted geographic region, as well as being limited by laws that require permission from residents to enter private property. While the Fire Department is launching a program in 2025 to pre-authorize inspector entry, moving over 9,000 parcels through this degree of modification will take too long.

The current Defensible Space Inspection program does not meet the threshold that would adequately prepare a neighborhood for exposure to a wildfire – primarily it lacks Ignition Zone 0. A more effective fire code must be combined with home hardening to meet minimum thresholds to create resilience. The resilience of an individual property only increases if done in conjunction with adjacent properties. Thus, successful implementation and enforcement will be more effective if concentrated in one region of the City at a time.

The Department will strive to implement these same recommendations in iterative phases that can be adjusted as the department and community continue to adapt to the changing landscape. The State may adopt more stringent requirements that cover a larger area at any time, which the city would be required to adopt. The proposed phases are:
 Phase I: Berkeley Fire Zone 3 and 4.
 Phase II: Other high-risk areas of Berkeley Fire Zone 2 determined based on topography, fuel and other conditions.
 Phase III +: The balance of the area defined by CalFIRE as a Very High Fire Hazard Severity Zone.

Limitations of Other Areas of Focus
Focusing on the values at risk (homes), and working outwards, is better supported by the evidence than trying primarily to address the origin of the fire, although these measures often receive less attention.6 The vegetative landscape east of Berkeley is dominated by large trees, often Eucalyptus globulus (Blue Gum). While mitigation of these trees is widely discussed as a solution, removal will not eliminate the risk or threat 6 Dale, L., Barrett, K. (2023). Missing the Mark : Effectiveness and Funding in Community Wildfire Risk Reduction. Headwaters Economics, Columbia Climate School. HE_2023_Missing-the-Mark-Wildfire.pdf

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of fire. In many of the above referenced destructive fires, the initial exposure into the built environment was from grass and low-lying shrubs. Removal of trees without a methodical and ongoing approach to mitigation will result in similar, fire prone conditions; grasslands still pose a significant regional threat7. The “historical” landscape before the arrival of Blue Gum Eucalyptus was fire-dependent, as well. The admittedly limited evidence around vegetation thinning beyond the immediate area around homes suggests limited effectiveness8,9 and one study suggests thinning may actually increase the chance of crown fires10; where fire moves into the treetops and can move exponentially faster than on the ground. In all research, extreme weather appears to nullify most interventions.11
Because the forested lands are outside of the City’s jurisdiction, and the limited evidence informing thinning and removal is inconclusive at best, fiscal prudence demands that we prioritize elsewhere.

Why implementing home hardening and Ignition Zone 0 together is key to hazard reduction
Two entities, widely considered to lead the science and best practices for wildfire mitigation, are cited here. The first is the National Institutes for Science and Technology (NIST) Wildland Urban Interface Division12 and the Insurance Institute for Business and Home Safety (IBHS)13, an independent, 501(c)(3) nonprofit scientific research and communications organization supported by property insurers, reinsurers, and affiliated companies. IBHS helps develop standards used by many insurers to establish how insurable a home is by understanding if they are prepared and defensible. 7 Cheney, N.P., Coleman, J., 1988. The level of fire risk associated with plantations. In:

Paper presented to Plantation 2020 The Local Government Perspective, 13–14 May 1988. Old Parliament House, King George Terrace Park, Canberra. P. 3 8 Mirra, I.M., Oliveria, T.M., Barros, A.M.G., Fernandes, P.M. (2017). Fuel Dynamics following fire hazard reductions treatments in blue gum (Eucalyptus globulus) plantations in Portugal. Forest Ecology and Management 398. P.1.
9 Weise, C.L., Brussee, B.E., Coates, P.S., Shinneman, D.J., Crist, M.R., Aldridge, C.L., Heinrichs, J.A., Ricca, M.A. (2023, September). A retrospective assessment of fuel break effectiveness for containing rangeland wildfires in the sagebrush biome. Journal of Environmental Management 341(1). https://www.sciencedirect.com/science/article/abs/pii/S0301479723006916 ct 10 Price, O.A., Bradstock, R.A., (2012). The efficacy of fuel treatment in mitigating property loss during wildfires: Insights from analysis of the severity of the catastrophic fires in 2009 in Victoria, Australia.

Journal of Environmental Management. Volume 113. p. 154 11 Price, O.A., Bradstock, R.A., (2012). The efficacy of fuel treatment in mitigating property loss during wildfires: Insights from analysis of the severity of the catastrophic fires in 2009 in Victoria, Australia.

Journal of Environmental Management. Volume 113. p. 1 p. 153 12 NIST. (2025, February 1). Wildland Urban Interface Group. https://www.nist.gov/el/fire-research- division-73300/wildland-urban-interface-fire-73305
13 Insurance Institute for Business & Home Safety (2025, February 1). IBHS. https://ibhs.org/risk- research/wildfire/

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Based on this research, many after action reports, and lived experience during numerous wildfires, the U.S. Fire Service has an understanding of the mitigations required to protect homes from wildfire. We have sufficient evidence to implement measures that would mitigate the cause of up to 90% of structure ignitions. The City of Berkeley has the ability to adopt these scientifically validated mitigation measures to reduce the vulnerability of our neighborhoods to wildfire ignition. Implementing these mitigations at scale sets our city on a path to a fire adapted future characterized by a significant reduction in the probability of a vegetative wildfire transitioning to an urban conflagration. However, these mitigations must be considered as a package.

Clear evidence shows that limited enforcement of a code that does not meet the current consensus requirements results in inadequate mitigation of risk. When it comes to mitigations against wildfire loss, both NIST and IBHS agree that “something is not better than nothing”. Wildfires pose an ignition threat to structures from both direct flame and embers, with embers being especially hazardous since they can travel long distances beyond municipal and property boundaries. While we can reduce the risk of wildfire spreading on the ground by managing vegetation and removing flammable materials around homes, embers remain a significant challenge. To truly protect a home, it must be "hardened" to resist both fire and embers—meaning it’s built or retrofitted with materials and features that can withstand these exposures. Partial hardening offers some protection in mild conditions but is nearly useless during fast moving wildfires as fire is opportunistic and finds gaps. The volume of embers a home is subjected to under these conditions requires complete compliance, as any one penetrating ember can result in the ignition that leads to complete structure loss. Additionally, accessory structures like sheds, pergolas, hot tubs or vehicles located too close to a home can catch fire and spread flames to the house. To provide homes the best chance of survival on their own [without organized suppression efforts] during a wildfire, they need thorough ember and fire hardening, along with thoughtful management of nearby hazards.

Mitigating some vegetation without, for instance, enforcing the ember resistant zone in the first five feet around a home to the proven standard, is not measurably helpful.

Neither is a private property with compliant vegetation where the home is not built to the current Chapter 7A of the building code (or retrofitted and hardened14), which provides the standard by which homes in the Wildland Urban Interface (WUI) should be built.,, This is because each mitigation action is complementary and provides a defense that other mitigations rely on. The wildfire scenario we may encounter is so persistent, that mitigating one part without the other will not save the home.

Creating Ignition Zone 0 and hardening a home is effective at reducing wildfire risk , but will not stop fires from spreading between houses once a structure catches fire. This is 14 CAL FIRE. (Retrieved 2025, February 1). Home Hardening: Address your home’s vulnerabilities to better withstand wildfire. https://www.fire.ca.gov/home-hardening

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because the heat energy produced from a burning house can be much greater than the heat from burning vegetation. In the Berkeley Hills, most homes are close together, making it easier for fires to spread from one house to another. If the fire department cannot respond quickly enough, house-to-house fires become the biggest danger.

Fighting just one house fire typically requires five to six fire apparatus and at least 15 firefighters. To give firefighters more time to respond and for residents to evacuate, we must take strong preventive actions now, before a wildfire ignites that will slow down its transition from vegetative fire to structural conflagration.

In partnership with stakeholders from throughout the community, we are proposing a trio of policies designed to develop a community that is prepared for exposure to wildfire.

These policies are structured around durable pre-fire measures proven to reduce the risk of structure ignitions.

Proposal 1: Establishing Berkeley Fire Zone 4, East of Grizzly Peak

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Map: New proposed Berkeley Zone 4. A quarter mile buffer that will help prevent the transition of a wind driven wildfire to a structure-to-structure conflagration15 While the City’s existing Defensible Space Inspection program has resulted in considerable progress, engagement, and compliance, it has also demonstrated the limitations of implementing change across a large swath of the City.

Adopting Ignition Zone 0 and home hardening in this proposed Berkeley Fire Zone 4 would create a buffer of prepared parcels along the eastern perimeter of the community with fewer vulnerabilities that can lead to structure ignition. Specifically, these homes would be more resistant to wildfire ignition through the combination of defensible space that minimizes the structure’s exposure to direct flame and radiant heat, reduces the presence of receptive fuel beds capable of supporting ember caused ignitions, and seals the structure against ember intrusion. The more time it takes a vegetative fire to ignite combustibles around homes and homes themselves, the more time there is for 15 https://www.google.com/maps/d/viewer?hl=en&mid=124Uo4PwX3EgwV9ula4jb9kRz5E1YBzc&ll=37.885 38150382334%2C-122.25720050000001&z=14

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the community to evacuate and for firefighting resources from around the region to amass in Berkeley and suppress the ignitions that do occur. Recent experience in Paradise16 (CA), Santa Rosa17 (CA), Lahaina18 (HI), Boulder County19 (CO), and Los Angeles20 (CA) clearly shows the results of wildfire becoming established in high density neighborhoods. Berkeley also has lessons painted in our institutional memories from 199121 and 192322
Prioritizing our resources in strategically targeted areas will benefit all of Berkeley. By focusing education, incentives, and enforcement on these adjoining properties we can achieve network effects and create a wildfire buffer. Contiguous properties that implement the scientifically validated best practices that follow will form a resilient unit, rather than a scattered, salt-and-pepper approach with some mitigated properties surrounded by those with unmitigated hazards. In fact, post-incident analysis of the Camp Fire in Paradise shows that, had the town of Paradise met the parameters that follow, a 53% reduction in loss would have occurred23.

Why did we choose these specific regions to begin this work? While a fire can ignite anywhere in the community, few locations within the built environment provide enough vegetative fuel to provide the “runway” necessary for a wildfire to gain the size, speed and energy required to transition to a structure-to- structure conflagration. The most likely scenario for a wildfire of this magnitude to occur 16 Porter, K., Scawthorn, C., Sandink, D. (2021) An impact analysis for the National Guide for Wildland- Urban Interface Fires., Institute for Catastrophic Loss Reduction. https://www.iclr.org/wp- content/uploads/2021/05/ICLR-SPA-Risk-Impact-Analysis-for-the-National-WUI-Fire-Guide-2021.pdf 17 Garrison, J. (2025, January 22). This California city lost thousands of homes to fire. Santa Rosa’s rebuilding has lessons for L.A. The Los Angeles Times. https://www.latimes.com/california/story/2025-01- 22/santa-rosa-offers-hope-lessons-for-rebuilding-after-la- fires#:~:text=On%20the%20night%20of%20Oct,at%20low%20risk%20for%20wildfire. 18 Kerber, S., Alkonis, D., (2024) Lahina Fire Comprehensive Timeline Report. UL Research Institutes Fire Safety Research Institute. https://fsri.org/research-update/lahaina-fire-incident-analysis-report- released-attorney-general-hawaii
19 Giammanco, I.M., Hedayati, F., Hawks, S.R., Sanchez Monroy, Z.S., Sluder, E. (2023). The Return of Conflagration in Our Built Environment. IBHS Wildfire Reseach Report. https://ibhs.org/suburban_wildfire_conflagration_whitepaper/ 20 IBHS. (2025). 2025 LA County Wildfires: Early Insights. The Insurance Institute for Business & Home Safety. https://ibhs.org/wp-content/uploads/2025-LAFires-EarlyInsights-FINAL.pdf 21 Sullivan, M., Fowler, D., Ed. (1993 December). Report on the Response of the Berkeley Department of Fire and Emergency Services to the Berkeley-Oakland Conflagration of 1991. City of Berkeley Department of Fire and Emergency Services.
22 Andrews, R.E., Raines, H. (1923). Report on the Berkeley, California Conflagration of September 17, 1923. National Board of Fire Underwriters Committee on Fire Prevention and Engineering Standards. 23 Chamberlain, M., Lee, R., Deacon, T., Watkins, N., David, K., Lei, F., Meftah, I. (2023) Town of Paradise California Resilience Challenge Task 1 to Task 4; Risk Reduction, Climate Change, and Insurance Premiums. Milliman and CoreLogic.

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is from an ignition to the east of the city within Tilden or Wildcat Canyon Regional Parks.

Such an ignition, during a Diablo Wind event, has the potential to significantly impact the eastern edges of Berkeley. If the properties at Berkeley’s eastern edge are not prepared to receive wildfire, they may facilitate a wildland fire’s transition to a structure- to-structure conflagration that would burn west toward the Bay until the wind stops or changes direction.

In addition to areas on Panoramic Hill (known as Berkeley Fire Zone 3), properties between Grizzly Peak Blvd and Wildcat Canyon Rd (proposed Berkeley Fire Zone 4) have one of the greatest wildfire exposure and access challenges in Berkeley. As such, it is important to implement focused wildfire risk reduction efforts in these areas. These efforts include education, incentives and enforcement to encourage adoption of enhanced defensible space and home hardening requirements that meet the scientific threshold for meaningful risk reduction. The areas east of Grizzly Peak Blvd arebounded by relatively wide roads, whose non-burnable features form a fire break separating private property from park lands and homes on the eastern aspect from those on the opposite west facing slope.

Proposal 2: Ignition Zone (Zone Zero) and Best Practice Modifications to the Fire Code in Berkeley Fire Zone 3 and 4
In August 2020, following Governor Gavin Newsom's proclamation of a State of Emergency due to widespread wildfires, the California State Legislature enacted Assembly Bill 3074 (AB 3074). This legislation established a critical new fire mitigation measure known as the "ember-resistant zone," or Zone 0. The law aimed to enhance existing defensible space requirements by requiring the five-foot perimeter surrounding structures in Fire Hazard Severity Zones24 to be cleared of combustible materials, a practice proven to significantly reduce the risk of structural ignition during wildfires.

We know that during a wildfire, embers from burning material fly long distances ahead of the fire front. When these embers find receptive fuel beds, which are often at the base of structures25, they can start new spot fires ahead of the main body of fire, essentially expanding the fire front exponentially. When these spot fires are adjacent to structures, those structures can also ignite.

Under the timeline mandated by AB 3074, new homes were expected to comply with Ignition Zone 0 regulations beginning in 2023, with existing homes required to comply starting in 2024. However, despite the legislative directive, the State has yet to complete 24 CAL FIRE. (retrieved February 1, 2025). Fire Hazard Severity Zones. Cal Fire. https://osfm.fire.ca.gov/what-we-do/community-wildfire-preparedness-and-mitigation/fire-hazard-severity- zones
25 Quarles, S. L., Standohar, C., Hedayati, F., & Gorham, D. (2023). Factors Influencing Ember Accumulation Near a Building. International Journal of Wildland Fire

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the formal rulemaking process necessary to implement these requirements. The delay in rulemaking has been attributed to political and administrative challenges.

During this same period of time, the insurance industry and the California Department of Insurance adopted Ignition Zone 0 as one component of how they measure wildfire risk.

The absence of Ignition Zone 0 from the Statewide fire code means that few communities are enforcing this standard. This then places homeowners in peril: even if their properties comply with the state and local code, they may face insurance non- renewal - or damage and destruction during a wildfire - because their property does not meet these scientifically validated standards. Further, the few homeowners who voluntarily adopt Ignition Zone 0 face significant risk from adjacent properties that have not adopted this mitigation measure.

The scientifically validated version of Ignition Zone 0 eliminates all combustible material within the first five feet of a home and any outbuildings, attached decks, and stairs.

Ignition Zone 0 also includes the area under attached decks and stair landings.

Materials not allowed include weeds, grass, plants (including climbing vines), debris, wood mulch products, combustible fencing and gates, plastic trash and recycle cans, trellis, pergolas, shade coverings, combustible planters, privacy walls, boats, RVs, vehicles, and other material that could be ignited by embers or direct flame. A version of Ignition Zone 0 that does not fully adopt this standard, and allows some fuel to remain, has not been studied and the benefits of a partial Ignition Zone 0 adoption have not been established.

Proactive steps to maintain Insurance
One common point of frustration with the current standards is that the existing fire code is less strict than the risk evaluation process of many insurers, who often follow the above-described evidence, leaving homeowners free of violations following an inspection, but unable to obtain insurance or facing non-renewal. Full adoption, and enforcement of the recommendations, outlined in this report would also align the affected home with industry standards for establishing risk. Because this would take place in a region, rather than with an individual property, congruent homes would meet the designation, likely reducing the overall neighborhood risk score. While the Department cannot guarantee this would increase eligibility in traditional insurance markets, it would align City requirements with the scientifically validated best practices adopted by that industry. Additionally, in cases where traditional insurance is still not an option, following these standards gives a home the scientifically validated best chance of survival during a wildfire.

Proposal 3: Quantifying the Negative – Fire Prevention, Resident Mitigation, Fire Department Staffing, and Mutual Aid
We often focus on the value of what is lost in a disaster. For instance, the economic impacts from the fires in Los Angeles County are staggering with some estimates as

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high as $275 billion. But what is the value of the property and lives saved by not just responders, but through proactive fire prevention and homeowner mitigation? What is the difference between what additional prevention measures – primarily those included in the EMBER initiative – will cost the community versus the additional property and lives that could have been saved?
The Quantifying the Negative (QTN) Approach is a peer reviewed methodology that measures the value of fire and emergency services by looking at what emergencies do not happen, or are mitigated before they expand, because of fire department efforts.

Typically, fire departments are seen as an expense, and fires and other disasters are described based on what was lost. This approach flips the perspective—it asks, what would have been lost if firefighters and paramedics were not there to stop an emergency from escalating? QTN calculates the value of homes, businesses, and lives saved, as well as the economic losses prevented by early intervention.

Instead of only focusing on what is lost in a fire or emergency, this approach highlights what was never destroyed—homes, jobs, businesses, and even entire communities— because of proactive investments ahead of an emergency.

This project will expand QTN methodology not just to fire department staffing and deployment, but also to fire prevention and resident mitigation efforts—particularly in preventing structure-to-structure conflagrations. This would provide the community with a clearer picture of the value of what could be protected and preserved due to the EMBER initiative.

This proposal would result in a report outlining the resulting, primarily financial gains that both residential and departmental interventions created by preventing or temporarily stalling wildfires. This could help city leaders and residents use data and financial models to make informed decisions that maximize public safety and economic stability.

ENVIRONMENTAL SUSTAINABILITY AND CLIMATE IMPACTS
Wildfires that transition to a structure-to-structure conflagration have acute and far- reaching consequences, not only for the environment and climate but also for the stability and well-being of impacted communities. These fires release large amounts of pollutants into the air, including soot and carbon dioxide, which contribute to climate change and degrade air quality. Additionally, toxic byproducts from burning structures, vehicles, and other synthetic material can pose significant health risks to residents and responders.

The water used to combat these fires is often sourced from the city's potable water supply. Once used, it can become contaminated with chemicals, ash, and debris, potentially polluting groundwater and local waterways.

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The destruction of homes, businesses, and critical infrastructure leads to substantial economic burdens that jeopardize the financial stability of impacted communities.

Rebuilding efforts require significant financial investment, as well as the production, transportation, and installation of new materials—all of which generate additional emissions. For individual residents, the loss of a home or business can lead to long- term financial instability, displacement, and increased insurance costs.

Beyond the physical and financial toll, these disasters leave lasting emotional and psychological scars on affected communities. Residents may experience trauma, anxiety, and grief, particularly when lives are lost, homes are destroyed, or neighborhoods are permanently altered. The social fabric of a community can be disrupted as families and businesses struggle to recover, sometimes forcing relocation and reducing neighborhood cohesion.

Investing in a strong fire code is one tool the city uses to reduce the frequency and severity of fires. Effective fire prevention also contributes to environmental sustainability by reducing emissions, preserving water resources, and minimizing the need for costly rebuilding efforts. A commitment to strong fire safety regulations ultimately benefits the entire community—protecting public health, safeguarding financial resources, and ensuring a resilient and sustainable future.

RATIONALE FOR RECOMMENDATION
The fire and seismic danger and other local conditions justify the proposed local amendments that are stricter than the California Fire Code.

A city, county, or city and county may establish more restrictive building standards as reasonably necessary because of local climatic, geological or topographical conditions.

The City’s adoption of stringent fuel mitigation and exterior hazard abatement standards is designed to decrease the risk of structure fires spreading to adjacent vegetation and the risk of vegetation fires spreading to structures. The Council bases these standards, in part, upon its finding that the climatic, vegetative, geological, and topographical conditions within the City create a grave risk of wildfire and resulting loss of life and property.

CONSIDERATIONS FOR COUNCIL
We live in a fire dependent landscape and it is inevitable that a wildfire will impact the city again.

So, the question is, if not this, then what? All the defensible space mitigations, primarily Zone 0, along with the home hardening measures, must be implemented on a sufficient number of contiguous parcels in a neighborhood for the wildfire hazard to be meaningfully reduced. Doing anything less has been validated to be almost meaningless with regard of hazard reduction.

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If we are unwilling or unable to move forward with EMBER, then the best use of our wildfire funds may be to continue to prepare to move residents out of the way of a fast- moving wildfire and prepare for substantially greater loss and the burden of rebuilding.

CONTACT PERSON
David Sprague, Fire Chief, 510-981-3473
Attachments:
1: Draft Ordinance – “Amendment of Section 19.48.020 of the Berkeley Municipal Code (“Amendments to The California Fire Code”)”
2: California Department of Insurance - Safer from Wildfire Standard 3: IBHS Wildfire Prepared Home - Base Designation Checklist

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ORDINANCE NO. ##,###–N.S.

REPEALING AND RE-ENACTING BERKELEY MUNICIPAL CODE CHAPTER 19.48 (BERKELEY FIRE CODE)
BE IT ORDAINED by the Council of the City of Berkeley as follows:

Section 1. That Berkeley Municipal Code Chapter 19.48 is hereby repealed and reenacted as to read as follows:

Chapter 19.48
BERKELEY FIRE CODE*
Sections:

19.48.010 Adoption of the California Fire Code including Appendix B – Fire- Flow Requirements for Buildings and Appendix L – Requirements for Fire Fighter Air Replenishment Systems

19.48.020 Amendments to the California Fire Code

19.48.030 Validity
Section 19.48.010 Adoption of the California Fire Code
A. The California Fire Code, 2022 edition, as adopted in Title 24, Part 9 of the California Code of Regulations, including Chapter 1 (excluding Section 103), Chapter 3, Section 503 of Chapter 5, Sections 1103.5.6 through 1103.5.6.3 (new sections as created by BMC 19.48.020, Amendments to the California Fire Code), Appendix Chapters D, E, F, L (as amended by BMC 19.48.020, Amendments to the California Fire Code) and O published by the International Code Council not included in the California Building Standards Code, are adopted by this reference into this Chapter, and are hereby adopted and made a part of this Chapter as though fully set forth herein, subject to the modifications thereto which are set forth this ordinance. One copy of this Code is on file in the office of the City Clerk of the City of Berkeley.

B. This chapter shall be known as the "Berkeley Fire Code" and shall be referred to in this chapter as "this code".

C. This Chapter will become effective on January 1, 2026.

Section 19.48.020 Amendments to the California Fire Code The following additions, changes and deletions to the 2022 California Fire Code, as detailed below, are adopted as part of the Berkeley Fire Code.

Chapter 1 of the California Fire Code is adopted in its entirety subject to the modifications thereto which are set forth below.

CHAPTER 1 – SCOPE AND ADMINISTRATION
SECTION 101 SCOPE AND GENERAL REQUIREMENTS

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[A] Section 101.1 Title. These regulations shall be known as the Berkeley Fire Code shall be known as the Fire Code of, shall be known as the Berkeley Fire Code, hereinafter referred to as "this code."
SECTION 102 APPLICABILITY
[A] 102.6 Historic buildings. The provisions of this code relating to the construction, alteration, repair, enlargement, restoration, relocation or moving of buildings or structures shall not be mandatory for existing buildings or structures identified and classified by the state or local jurisdiction as historic buildings where such buildings or structures do not constitute a distinct hazard to life or property. Fire protection in designated historic buildings shall be provided with an approved fire protection plan as required in Section 1103.1.1 in accordance with the 2022 California Historical Code.

SECTION 104 DUTIES AND POWERS OF THE FIRE CODE OFFICIAL Section 104.13. Authority to arrest and issue citations. The Fire Chief, or their designee shall have authority to arrest or to cite any person who violates any provision of this Chapter involving the International Fire Code or the California Building Standards Code regulations relating to fire and panic safety as adopted by the State Fire Marshal, in the manner provided for the arrest or release on citation and notice to appear with respect to misdemeanors or infractions, as prescribed by Chapters 5, 5c and 5d of Title 3, Part 2 of the California Penal Code, including Section 853.6, or as the same hereafter may be amended. It is the intent of the City Council that the immunities provided in Penal Code Section 836.5 are applicable to aforementioned officers and employees exercising their arrest or citation authority within the course and scope of their employment pursuant to this Chapter.

Section 104.14 Authority to abate fire nuisance [Aditional subsection]. The Fire Chief or the Fire Chief’s designee shall have the authority to order the abatement of fire nuisances.

SECTION 105 PERMITS
105.5.18 Flammable and combustible liquids. An operational permit is required:

1. To use or operate a pipeline for the transportation within facilities of flammable or combustible liquids. This requirement shall not apply to the offsite transportation in pipelines regulated by the Department of Transportation (DOT) nor does it apply to piping systems.

2. To store, handle or use Class I liquids in excess of 5 gallons (19 L) in a building or in excess of 10 gallons (37.9 L) outside of a building, except that a permit is not required for the following:

2.1 The storage or use of Class I liquids in the fuel tank of a motor vehicle, aircraft, motorboat, mobile power plant or mobile heating plant, unless such storage, in the opinion of the fire code official, would cause an unsafe condition.

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2.2 The storage or use of paints, oils, varnishes or similar flammable mixtures where such liquids are stored for maintenance, painting or similar purposes for a period of not more than 30 days.

3. To store, handle or use Class II or Class IIIA liquids in excess of 25 gallons (95 L) in a building or in excess of 60 gallons (227 L) outside a building, except for fuel oil used in connection with oil-burning equipment.

4. To store, handle or use Class IIIB liquids in excess of 110 gallons in containers, or in tanks or portable tanks for fueling motor vehicles at motor fuel-dispensing facilities or where connected to fuel-burning equipment.

Exception: Fuel oil and used motor oil used for space heating or water heating.

5. To remove Class I or II liquids from an underground storage tank used for fueling motor vehicles by any means other than the approved, stationary on-site pumps normally used for dispensing purposes.

6. To operate tank vehicles, equipment, tanks, plants, terminals, wells, fuel- dispensing stations, refineries, distilleries and similar facilities where flammable and combustible liquids are produced, processed, transported, stored, dispensed or used.

7. To place temporarily out of service (for more than 90 days) an underground, protected above-ground or above-ground flammable or combustible liquid tank.

8. To change the type of contents stored in a flammable or combustible liquid tank to a material that poses a greater hazard than that for which the tank was designed and constructed.

9. To manufacture, process, blend or refine flammable or combustible liquids.

10. To engage in the dispensing of liquid fuels into the fuel tanks of motor vehicles at commercial, industrial, governmental or manufacturing establishments in accordance with Section 5706.5.4 or to engage in on-demand mobile fueling operations in accordance with Section 5707.

11. To utilize a site for the dispensing of liquid fuels from tank vehicles into the fuel tanks of motor vehicles, marine craft and other special equipment at commercial, industrial, governmental or manufacturing establishments in accordance with Section 5706.5.4 or, where required by the fire code official, to utilize a site for on-demand mobile fueling operations in accordance with Section 5707.

Section 105.5.55 Christmas tree sales lot. An operational permit is required to operate a Christmas tree sales lot.

Section 105.5.56 Escort convoy service. Police and/or Fire Department convoy service is required for vehicle transportation of extremely hazardous materials.

Section 105.5.57 Fire Fighter Air Replenishment System (FARS). An annual operational permit is required to maintain a FARS system in accordance with Appendix L.

Section 105.5.58 General use permit. For any activity or operation not specifically described in this code, which the fire code official reasonably determines, may produce conditions hazardous to life or property.

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Section 105.5.59 Parking facility, special events] An operational permit is required to use buildings or structures for vehicle parking, including parking for special events (i.e. football games, etc.).

Section 105.6.25 Fire fighter air replenishment system (FARS). A construction permit is required for installation of or modification to a FARS system in accordance with Appendix L.

Section 105.6.26 Window bars, operational constraints and opening control devices. A construction permit is required to install window bars or other equipment which imposes operational constraints and opening controls on emergency escape and rescue openings on exterior doors or windows of any sleeping rooms in accordance with fire code Section 1031.2.1 of this code.

SECTION 107 FEES
Section 107.2 Schedule of permit fees. Where a permit is required, a fee for each permit shall be paid as required, in accordance with the schedule as established by the applicable governing body. of fees for permits and inspections as set forth by the City Council by resolution.

Section 107.4 Work commencing before permit issuance. A person who commences any work, activity or operation regulated by this code before obtaining the necessary permits shall be subject to a fee established by the applicable governing authority, which shall be in addition to the required permit fees. equivalent to three times the amount of the required fees to obtain a permit for that work, activity or operation regulated by this code.

Section 107.7. Expense of securing emergencies. The expense of securing any emergency that is within the responsibility for enforcement of the fire code official as given in Sections 104.1 or 104.11 is a charge against the person who caused the emergency. Damages and expenses incurred by any public agency having jurisdiction or any public agency assisting the agency having jurisdiction shall constitute a debt of such person and shall be collectible by the fire code official for proper distribution in the same manner as in the case of an obligation under contract expressed or implied.

Expenses as stated above shall include, but not be limited to, equipment and personnel committed and any payments required by the public agency to outside business firms requested by the public agency to secure the emergency, monitor remediation, and clean up.

SECTION 111 MEANS OF APPEALS
Section 111.1 Board of appeals established. Appeals Procedure In order to hear and decide appeals of orders, decisions or determinations made by the fire code official relative to the application and interpretation of this code, there shall be and is hereby created a board of appeals. The board of appeals shall be appointed by the applicable governing authority and shall hold office at its pleasure. The board shall adopt rules of procedure for conducting its business and shall render all decisions and findings in writing to the appellant with a duplicate copy to the fire code official. an appeal therefore may be taken to the City Council by the applicant or permit holder. Notice of the appeal

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must be filed with the City Clerk of the City of Berkeley within ten days from the date of mailing of the fire code official’s decision to the applicant or permit holder. The notice of appeal shall contain a statement of the reasons for the appeal. The City Clerk shall forward one copy thereof to the fire code official. Within thirty days after the filing of the notice of appeal, the fire code official shall transmit to the City Council all their records pertaining to the decision appealed from.

Section 111.1.1 Stay of Proceedings The filing of the notice of appeal shall stay all proceedings by all parties in connection with the matter upon which the appeal is taken until determination of the appeal as hereinafter provided, unless the fire code official determines that such a stay could result in an imminent threat to public safety.

Section 111.3 Qualifications. The board of appeals shall consist of members who are qualified by experience and training to pass on matters pertaining to hazards of fire, explosions, hazardous conditions or fire protection systems, and are not employees of the jurisdiction. Decisions: The City Council shall review the action of the fire code official and shall do any one of the following:
a. Refer the matter back to the fire code official.
b. If the facts stated in or ascertainable from the application, the Notice of Appeal, the written statement of the fire code official setting forth the reason for their decision, and the other papers, if any, constituting the record do not, in the opinion of the City Council, warrant further hearing, the City Council may affirm the decision of the fire code official. Such decision shall be final. c. If, in the opinion of the City Council, said facts warrant further hearing, the City Council shall set the matter for hearing and shall give notice of the time and place of said hearing by mailing a copy of such notice by certified mail to the address of the applicant as stated in the Notice of Appeal, at least ten (10) days before the time fixed for the hearing. The City Council may continue the hearing from time to time.
d. Following such hearing, the City Council shall reverse, affirm wholly or partly modify any decision of the fire code official, or make any other decisions or determinations or impose such conditions as the facts warrant. Such decision or determination shall be final.
e. If none of the above actions have been taken by the City Council within thirty (30) days from the date the appeal first appears on the City Council agenda, then the decision of the fire code official shall be deemed affirmed and the appeal shall be deemed dismissed.
f. If the appeal is set for hearing but the disposition of the appeal has not been determined within ninety (90) days from the date the appeal first appears on the City Council agenda, then the decision of the fire code official shall be deemed affirmed and the appeal deemed dismissed.
111.4 Administration. The fire code official shall take immediate action in accordance with the decision of the Board City Council .

SECTION 112 VIOLATIONS

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Section 112.1 Unlawful acts [Amended subsection]. It shall be unlawful for a person, firm or corporation to erect, construct, alter, repair, remove, demolish or utilize a building, occupancy, premises or system regulated by this code, or cause same to be done, in conflict with or in violation of any of the provisions of this code, or to create, maintain or allow to continue any fire hazard.

Section 112.4 Violation penalties . Persons who shall violate a provision of this code or shall fail to comply with any of the requirements thereof or who shall erect, install, alter, repair or do work in violation of the approved construction documents or directive of the fire code official, or of a permit or certificate used under provisions of this code, shall be guilty of a [SPECIFY OFFENSE], punishable by a fine of not more than [AMOUNT] dollars or by imprisonment not exceeding [NUMBER OF DAYS], or both such fine and imprisonment misdemeanor, but may be cited or charged, at the election of the enforcing officer or City Attorney, as infractions, subject to an election by the defendant under Penal Code Subsection 17 (d). Each day that a violation continues after due notice has been served shall be deemed a separate offense. In addition to all other legal remedies, civil or criminal (as set forth above), any violation of this code constitutes a public nuisance in accordance with B.M.C Chapter 1.26, and is subject to all provisions of B.M.C. Chapter 1.26, as well as abatement under B.M.C. Chapter 1.24, “Abatement of Nuisances”. All such violations are also subject to the issuance of an administrative citation in accordance with B.M.C Chapter 1.28 at the discretion of the enforcing officer or the City Attorney.

SECTION 114 UNSAFE STRUCTURES OR EQUIPMENT
Section 114.7 Summary abatement. Where conditions exist that are deemed hazardous to life and property, the fire code official or fire department official in charge of the incident is authorized to abate summarily such hazardous conditions that are in violation of this code. Where the owner does not comply with an abatement order under Section 114.4 within the period specified, the City of Berkeley may perform or cause to be performed the necessary work. The costs incurred shall be recoverable under the procedures in Section 114.7.1
Section 114.7.1 Abatement process [Additional subsection] The abatement process shall be conducted in accordance with the notice and hearing requirements of the nuisance abatement provisions of Berkeley Municipal code chapter 1.24, including summary abatements of structures or premises determined by the City of Berkeley to constitute an imminent hazard or emergency condition.

Chapter 2 of the California Fire Code is adopted in its entirety subject to the modifications thereto which are set forth below.

CHAPTER 2 – DEFINITIONS
SECTION 202 GENERAL DEFINITIONS
Section 202 Definitions – BBERKELEY MARINA. The area shall mean all those, parts of the City of Berkeley west of the Interstate 80 Freeway

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Section 202 (Definitions — F). FIRE HAZARD. Anything or act which increases or could cause an increase of the hazard or menace of fire to a greater degree than that customarily recognized as normal by persons in the public service regularly engaged in preventing, suppressing or extinguishing fire or anything or act which could obstruct, delay, hinder or interfere with the operations of the fire department or the egress of occupants in the event of fire. Fire hazards as defined herein are hereby declared to be public nuisances subject to abatement by the City of Berkeley.

Section 202 (Definitions — F). FIRE NUISANCE. Anything or act, which is annoying, unpleasant, offensive or obnoxious because of fire.

Section 202 (Definitions – J). JURISDICTION. The City of Berkeley. The governmental unit that has adopted this code.

Section 202 (Definitions — W). WASTE OIL is a Class III-B waste liquid resulting from the use of Class III-B combustible liquids such as waste motor oil, hydraulic oil, lubricating oil, brake fluids and transmission fluids.

Chapter 5 of the California Fire Code is adopted in its entirety subject to the modifications thereto which are set forth below.

CHAPTER 5 – FIRE SERVICE FEATURES
SECTION 504 ACCESS TO BUILDING OPENINGS AND ROOFS
Section 504.1.1 Marking of Exterior Building Openings. Where exterior doorways are not otherwise marked with identification such as building addresses, room/suite numbers or business names which identify the area(s) they provide access to, or a functional description for the space, such opening shall be provided with signs or labels indicating the areas they serve. Doorways to be marked shall include but are not limited to doors serving building circulation (such as stairwells/exit passageways), potential hazards (such as trash rooms), and building service and utility spaces (such as electrical, gas, HVAC and elevator machine rooms). Signs/labels shall be permanent, weather and sunlight resistant with lettering not less than ¾” high with a 1/16” width stroke on a contrasting background. Such signs or labels shall be affixed to the door frame or wall above the door. Such signs and labels shall be maintained.

Exception: Doors associated with private dwellings, the main entrance to normally occupied spaces or when determined to be unnecessary by the fire code official.

Chapter 7 of the California Fire Code is adopted in its entirety subject to the modifications thereto which are set forth below.

CHAPTER 7 – FIRE AND SMOKE PROTECTION FEATURES
SECTION 705 DOOR AMD WINDOW OPENINGS
Section 705.2.5 Smoke - and heat-activated doors. Smoke-activated doors shall be maintained to self-close or automatically close upon detection of smoke. Existing fusible-link-type automatic-door closing devices are permitted if the fusible-link rating does not exceed 135F (57C). Doors required for fire and smoke separation for interior

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exit stairways and floor separation in R-1 or R-2 occupancies shall not be maintained in an open position with fusible links.

Chapter 9 of the California Fire Code is adopted in its entirety subject to the modifications thereto which are set forth below.

CHAPTER 9 – FIRE PROTECTION AND LIFE SAFETY SYSTEMSSECTION 903

AUTOMATIC SPRINKLER SYSTEMS
Section 903.2.10.1 Commercial parking garages. An automatic sprinkler system shall be provided throughout buildings used for storage of commercial motor vehicles where the fire arear exceeds 5,000 square feet (464 m2).

Section 903.2.11.1 Stories without openings. An automatic sprinkler system shall be installed throughout all buildings having stories, including basements, of all buildings where the floor area exceeds 1,500 square feet (139.4 m 2) and where the story does not comply with the following types of exterior wall openings:

1. Openings below grade that lead directly to ground level by an exterior stairway complying with Section 1011 or an outside ramp complying with Section 1012.

Openings shall be located in each 50 linear feet (15 240 mm), or fraction thereof, of exterior wall in the story on not fewer than one side. The required openings shall be distributed such that the lineal distance between adjacent openings does not exceed 50 feet (15 240 mm).

2. Openings entirely above the adjoining ground level totaling not less than 20 square feet (1.86 m 2) in each 50 linear feet (15 240 mm), or fraction thereof, of exterior wall in the story on not fewer than one side. The required openings shall be distributed such that the lineal distance between adjacent openings does not exceed 50 feet (15 240 mm) The height of the bottom of the clear opening shall not exceed 44 inches (1118 mm) measured from the floor.

Section 903.2.11.2. Rubbish, Recycling and linen chutes. An automatic sprinkler system shall be installed at the top of rubbish and linen chutes and in their terminal rooms. Chutes shall have additional sprinkler heads installed at alternate floors and at the lowest intake. Where a rubbish chute extends through a building more than one floor below the lowest intake, the extension shall have sprinklers installed that are recessed from the drop area of the chute and protected from freezing in accordance with Section 903.3.1.1. Such sprinklers shall be installed at alternate floors, beginning with the second level below the last intake and ending with the floor above the discharge. Access to sprinklers in chutes shall be provided for servicing. Activation of any fire sprinkler in a chute shall activate a separate water flow switch to indicate waterflow in the chute. All fire sprinklers in the chute shall be controlled by a separate, electrically supervised control valve with tamper switch.

Section 903.2.22 Structures in the Berkeley Marina Area. An automatic sprinkler system shall be installed in all structures located in the Berkeley Marina Area in accordance with NFPA 13 standards.

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Exceptions: Gear lockers not designed to permit human entry, municipal restrooms unattached to other structures, the existing City of Berkeley Harbor Master's office, and any temporary construction site structures.

Section 903.2.23 Public Self-Storage Buildings. An automatic sprinkler system shall be installed in any building erected or existing building that was converted and/or subdivided for public self-storage use on or after August 19, 1982, in accordance with NFPA 13 standards.

Section 903.2.24 Environmental Safety - Residential District. The construction of any new structure requiring a permit determined to be $150,000 or more in construction costs OR new additions to existing structures shall be required to install automatic fire sprinklers throughout the structure. This section does not apply to work defined as Alterations or Repairs as defined by the building code. For the purpose of this subsection “Environmental Safety – Residential District” shall mean those areas designated as such on the Official Zoning Map of the City of Berkeley, as it may be amended from time to time.”
Section 903.3.1.2 NFPA 13R sprinkler systems. Automatic sprinkler systems in Group R occupancies shall be permitted to be installed throughout in accordance with NFPA 13R as amended in Chapter 80.

1. Four stories or less above grade plane.

2. The floor level of the highest story is 30 feet (9144mm) or less above the lowest level of fire department vehicle access.

3. The floor level of the lowest story is 30 feet (9144mm) or less below the lowest level of fire department access.

The number or stores of Group R occupancies constructed in accordance with Sections 510.2 and 510.4 of the California Building Code shall be measured from grade plane.

Exception: Sprinkler systems in residential / commercial mix-use buildings are to be in accordance with NFPA 13.

Section 903.3.9 Floor control valves. Floor control valves and waterflow detection assemblies shall be installed at each floor where any of the following occur:

1. Buildings where the floor level of the highest story is located more than 30 feet or more above the lowest level of fire department vehicle access.

2. Buildings that are four three or more stories in height.

3. Buildings that are two or more stories below the highest level of fire department vehicle access.

Exception: In Group R-3 and R-3.1 occupancies, floor control valves and waterflow detection assemblies shall not be required.

Section 907.2 Where required—new buildings and structures. An approved fire alarm system installed in accordance with the provisions of this code and NFPA 72 shall be provided in new buildings and structures in accordance with Sections 907.2.1 through 907.2.29 and provide occupant notification in accordance with Section 907.5, unless other requirements are provided by another section of this code.

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Not fewer than one manual fire alarm box shall be provided in an approved location to initiate a fire alarm signal for fire alarm systems employing automatic fire detectors or water-flow detection devices. Where an automatic and manual, or a manual fire alarm system is required by this code or Berkeley local ordinance, other sections of this code allow elimination of fire alarm boxes is prohibited. due to sprinklers or automatic fire alarm systems, a single fire alarm box shall be installed at a location approved by the enforcing agency.

Exceptions:

1. The manual fire alarm box is not required for fire alarm control units dedicated to elevator recall control, supervisory service and fire sprinkler monitoring.

2. The manual fire alarm box is not required for GroupR-2 occupancies unless required by the fire code official to provide a means for fire watch personnel to initiate an alarm during a sprinkler system impairment event. Where provided, the manual fire alarm box shall not be located in an area that is open to the public.

3. The manual fire alarm box is not required to be installed when approved by the fire code official.

Section 907.2.1 Group A. A manual fire alarm system that activates the occupant notification system in accordance with Section 907.5 shall be installed in Group A occupancies where the occupant load due to the assembly occupancy is 300 or more, or where the Group A occupant load is more than 100 persons above or below the lowest level of exit discharge. Group A occupancies not separated from one another in accordance with Section 707.3.10 of the California Building Code shall be considered as a single occupancy for the purposes of applying this section. Portions of Group E occupancies occupied for assembly purposes with an occupant load of less than 1000 shall be provided with a fire alarm system as required for the Group E occupancy.

Exception: Manual fire alarm boxes are not required where the building is equipped throughout with an automatic sprinkler system installed in accordance with Section 903.3.1.1 and the occupant notification appliances will activate throughout the notification zones upon sprinkler water flow.

Every Group A building used for educational purposes shall be provided with a manual or automatic fire alarm system. This provision shall apply to, but shall not necessarily be limited to, every community college and university.

Exception: Privately owned trade or vocational schools or any firm or company which provides educational facilities and instruction for its employees.

Section 907.2.2 Group B. A manual fire alarm system, which activates the occupant notification system in accordance with Section 907.5, shall be installed in Group B occupancies where one of the following conditions exists:

1. The combined Group B occupant load of all floors is 500 or more.

2. The Group B occupant load is more than 100 persons above or below the lowest level of exit discharge.

3. The fire area contains an ambulatory care facility.

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4. For Group B occupancies containing educational facilities, see Section 907.2.2.2.

Exception: Manual fire alarm boxes are not required where the building is equipped throughout with an automatic sprinkler system installed in accordance with Section 903.3.1.1 and the occupant notification appliances will activate throughout the notification zones upon sprinkler water flow.

Section 907.2.4 Group F. A manual fire alarm system that activates the occupant notification system in accordance with Section 907.5 shall be installed in Group F occupancies where both of the following conditions exist:

1. The Group F occupancy is two or more stories in height.

2. The Group F occupancy has a combined occupant load of 500 or more above or below the lowest level of exit discharge.

Exception: Manual fire alarm boxes are not required where the building is equipped throughout with an automatic sprinkler system installed in accordance with Section 903.3.1.1 and the occupant notification appliances will activate throughout the notification zones upon sprinkler water flow.

Section 907.2.7 Group M. A manual fire alarm system that activates the occupant notification system in accordance with Section 907.5 shall be installed in Group M occupancies where one of the following conditions exists:

1. The combined Group M occupant load of all floors is 500 or more persons.

2. The Group M occupant load is more than 100 persons above or below the lowest level of exit discharge.

Exceptions:

1. A manual fire alarm system is not required in covered or open mall buildings complying with Section 402 of the California Building Code.

2. Manual fire alarm boxes are not required where the building is equipped throughout with an automatic sprinkler system installed in accordance with Section 903.3.1.1 and the occupant notification appliances will automatically activate throughout the notification zones upon sprinkler water flow.

Section 907.2.8.1 Manual fFire alarm system. A manual and automatic fire alarm system that activates the occupant notification system in accordance with Section 907.5 shall be installed in Group R-1 occupancies.

Exceptions:

1. A manual fire alarm system is not required in buildings not more than two stories in height where all individual sleeping units and contiguous attic and crawl spaces to those units are separated from each other and public or common areas by not less than 1-hour fire partitions and each individual sleeping unit has an exit directly to a public way, egress court or yard.

2. Manual fire alarm boxes are not required throughout the building where all the following conditions are met:

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2.1.The building is equipped throughout with an automatic sprinkler system installed in accordance with Section 903.3.1.1 or 903.3.1.2.

2.2.The notification appliances will activate upon sprinkler water flow.

2.3.Not fewer than one manual fire alarm box is installed at an approved location.

Section 907.2.8.2 Manual and Aautomatic fire alarm systemsmoke detection system. An A manual and automatic smoke detectionfire alarm system that activates the occupant notification system in accordance with Section 907.5 shall be installed throughout all interior corridors and common areas of Group R-1 occupancies. The detection device for this purpose shall be a smoke detector (or heat detector as approved), which is system connected and electronically supervisedserving sleeping units.

Exception: An automatic smoke detection system is not required in buildings that do not have interior corridors serving sleeping units and where each sleeping unit has a means of egress door opening directly to an exit or to an exterior exit access that leads directly to an exit.

Section 907.2.9.1 Automatic and Mmanual fire alarm system. An automatic and manual fire alarm system that activates the occupant notification system in accordance with Section 907.5 shall be installed in Group R-2 occupancies where any of the following conditions apply:

1. The building is three or more stories in height and Any any dwelling unit or sleeping unit is located three or more stories above the lowest level of exit discharge.

2. Any dwelling unit or sleeping unit is located more than one story below the highest level of exit discharge of exits serving the dwelling unit or sleeping unit.

3. The building contains more than 16 dwelling units or sleeping units.

4. Congregate residences with more than 16 occupants.

Exceptions:

1. A fire alarm system is not required in buildings not more than two stories in height where all dwelling units or sleeping units and contiguous attic and crawl spaces are separated from each other and public or common areas by not less than 1-hour fire partitions and each dwelling unit or sleeping unit has an exit directly to a public way, egress court or yard.

2. Manual fire alarm boxes are not required where the building is equipped throughout with an automatic sprinkler system installed in accordance with Section 903.3.1.1 or 903.3.1.2 and the occupant notification appliances will automatically activate throughout the notification zones upon a sprinkler water flow.

3. 2. A fire alarm system is not required in buildings that do not have interior corridors serving dwelling units and are protected by an approved automatic sprinkler system installed in accordance with Section 903.3.1.1 or 903.3.1.2,

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provided that dwelling units either have a means of egress door opening directly to an exterior exit access that leads directly to the exits or are served by open-ended corridors designed in accordance with Section 1027.6, Exception 3.

Section 914.3.9 Fire Fighter Air Replenishment Systems. New high-rise buildings shall install an approved Fire Fighter Air Replenishment System (FARS) or equivalent equipment or systems as determined by the fire code official to provide a breathing air supply for firefighting self-contained breathing air tanks. Such system or equipment shall provide adequate pressurized breathing air supply through a permanent piping system or other means acceptable to the fire code official for the replenishment of portable life sustaining air equipment carried by fire department, rescue and other personnel in the performance of their duties. Design, installation, testing and maintenance of such air replenishment systems shall be made in accordance with Appendix Chapter F of the California Plumbing Code. Each property owner shall be responsible for maintaining such equipment or systems including annual air sampling and testing.

Exceptions:

1. Buildings equipped with Firefighter Access Elevators as required by Berkeley Building Code section 403.6.1

2. Where an alternate method of supplying breathing air replenishment is approved by the fire code official.

Chapter 11 of the California Fire Code is adopted in its entirety subject to the modifications thereto which are set forth below.

CHAPTER 11 – CONSTRUCTION REQUIREMENTS FOR EXISTING BUILDINGS SECTION 1103 FIRE SAFETY REQUIREMENTS FOR EXISTING BUILDINGS Section 1103.5 Sprinkler systems. An automatic sprinkler system shall be provided in existing buildings in accordance with Section 1103.5.1 through 1103.5.5.6.3 SECTION 1103.5.6 AUTOMATIC SPRINKLER REQUIREMENTS FOR EXISTING HOTELS
Section 1103.5.6.1 Definitions. For the purposes of this Section, the following terms shall be defined as follows:

1. “Hotel" shall mean any building, including motels, dormitories, rooming houses, fraternity houses and sorority houses, which contain six or more rooms which were intended or designed to be used, or which are used, for the purposes of renting, hiring or letting to residential occupants for sleeping purposes but shall not include apartment buildings as defined in this code.

2. "Story" is as defined in the Berkeley Building Code.

3. "First Story" is as defined in the Berkeley Building Code.

4. "Basement" is as defined in the Berkeley Building Code.

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5. “Balcony, Exterior Exit" shall mean a landing or porch projecting from the wall of a building which serves as a required exit. The long side shall be at least 50 percent directly open to the exterior, and the open area above the guardrail shall be so configured as to prevent the accumulation of smoke or toxic gases.

Application: This section shall apply to every hotel in which the rooms used for sleeping are rented or let above the ground floor, if the hotel was built prior to 1992, and also meets one of the following two conditions:

The height of the hotel is three or more stories or two stories plus an inhabited basement, which is used for purposes other than exclusively servicing the maintenance and other needs of the building; or the hotel contains 20 or more rooms, or regularly accommodates 20 or more residential occupants.

Exception: No hotel in which the exits from sleeping rooms lead either to the outside of the building either directly or via approved exit balconies with approved exterior stairways(s) in accordance with the requirements of the Berkeley Building Code is required to comply with this section.

Section 1103.5.6.2 Types of Fire Sprinklers. In the sleeping units of the building, only residential or quick response sprinkler heads shall be used.

Section 1103.5.6.3 Supervision of fire sprinkler systems. All automatic sprinkler systems installed under this subsection shall be monitored for supervision and alarms in accordance with Section 903.4.

Section 1103.7 Fire Alarm Systems. An approved fire alarm system shall be installed in existing buildings and structures in accordance with Sections 1103.7.1 through 1103.7.6 and provide occupant notification in accordance with Section 907.5 unless other requirements are provided by other sections of this code. Existing high-rise buildings shall comply with Section 1103.7.9. Where an automatic and manual or a manual fire alarm system is required by this code or Berkeley local ordinance, elimination of fire alarm boxes in buildings equipped with an approved sprinkler system is prohibited.

Exception: Occupancies with an existing, previously approved fire alarm system.

Section 1103.7.5.1 Group R-1 hotels, and motels, and congregate residences manual and automatic fire alarm system. A manual and automatic fire alarm system that activates the occupant notification system in accordance with Section 907.5 shall be installed in existing Group R-1 hotels, and motels, and congregate residences more thanwith three or more stories or with more than 20 or more sleeping units.

Exceptions:

1. A manual fire alarm system is not required in buildings less than two stories in height where all sleeping units, attics and crawl spaces are separated by 1-hour fire-resistance-rated construction and each sleeping unit has direct access to a public way, egress court or yard.

2. A manual fire alarm system is not required in buildings not more than three stories in height with not more than 20 sleeping units and equipped throughout with an automatic sprinkler system installed in accordance with Sections 903.3.1.1 or 903.3.1.2.

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3. Manual fire alarm boxes are not required throughout the building where the following conditions are met:

3.1. The building is equipped throughout with an automatic sprinkler system installed in accordance with Section 903.3.1.1 or 903.3.1.2.

3.2. The notification appliances will activate upon sprinkler water flow.

3.3. Not less than one manual fire alarm box is installed at an approved location.

Section 1103.7.6 Group R-2. A manual and automatic fire alarm system that activates the occupant notification system in accordance with Section 907.5 shall be installed in existing Group R-2 occupancies three or more stories in height or with 16 or more dwelling or sleeping units. Congregate residences shall retrofit existing manual-only fire alarm systems with manual and automatic fire detection. Other types of R-2 occupancies (such as apartment buildings) shall retrofit existing manual-only fire alarm systems with manual and automatic fire detection when the existing fire alarm control unit is replaced for any reason. Automatic detection shall be accomplished by use of a smoke detector (or heat detector as approved), which is system connected and electronically supervised. Detectors shall be installed in all interior corridors and common areas.

Exceptions:

1. Where each living unit is separated from other contiguous living units by fire barriers having a fire-resistance rating of not less than 3/4 hour, and where each living unit has either its own independent exit or its own independent stairway or ramp discharging at grade.

2. A separate fire alarm system is not required in buildings that are equipped throughout with an approved supervised automatic sprinkler system installed in accordance with Section 903.3.1.1 or 903.3.1.2 and having a local alarm to notify all occupants.

3. A fire alarm system is not required in buildings that do not have interior corridors serving dwelling units and are protected by an approved automatic sprinkler system installed in accordance with Section 903.3.1.1 or 903.3.1.2, provided that dwelling units either have a means of egress door opening directly to an exterior exit access that leads directly to the exits or are served by open ended corridors designed in accordance with Section 1027.6, Exception 3.

4. A fire alarm system is not required in buildings that do not have interior corridors serving dwelling units, do not exceed three stories in height and comply with both of the following:

4.1. Each dwelling unit is separated from other contiguous dwelling units by fire barriers having a fire-resistance rating of not less than ¾ hour.

4.2. Each dwelling unit is provided with smoke alarms complying with the requirements of Section 907.2.11.

Section 1103.7.10 Monitoring of Group R Occupancies. All existing R occupancies that are required to provide both a fire alarm and fire suppression system shall have the

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system monitored by a central station, remote supervising station, or proprietary supervising station.

Chapter 49 of the California Fire Code is adopted in its entirety subject to the modifications thereto which are set forth below.

CHAPTER 49 – REQUIREMENTS FOR WILDLAND-URBAN INTERFACE FIRE AREAS
SECTION 4902 DEFINITIONS
Section 4902.1 General. For the purpose of this chapter, certain terms are defined as follows:

DIRECTOR. Director of the California Department of Forestry and Fire Protection (CAL FIRE).

FIRE PROTECTION PLAN. A document prepared for a specific premises, project or development, either existing or proposed for a Wildland-Urban Interface (WUI) area. It describes ways to minimize and mitigate potential for loss from wildfire exposure.

FIRE HAZARD SEVERITY ZONES. Geographical areas designated pursuant to California Public Resources Codes, Sections 4201 through 4204 and classified as Very High, High, or Moderate in State Responsibility Area or as Local Agency Very High Fire Hazard Severity Zones designated pursuant to California Government Code, Sections 51175 through 51189.

The California Code of Regulations, Title 14, Section 1280 entitles the maps of these geographical areas as "Maps of the Fire Hazard Severity Zones in the State Responsibility Area of California."
FIRE ZONE ONE shall encompass the entire City of Berkeley except for Fire Zones Two and Three.

FIRE ZONE TWO encompasses those areas designated as Combined Hillside District in the Official Zoning map of the City of Berkeley and those areas designated as Very High in the official Fire Hazard Severity Zones (FHSZ) map of the California Department of Forestry and Fire Protection (CAL FIRE), as they may be amended from time to time. The following properties, not part of the Combined Hillside District, are included in Fire Zone Two under the Very High designation of the FHSZ map: the eastern section of the University of California, Berkeley main campus, block number 2042 (Alameda County Assessor’s parcel numbering (APN) system), to the east city line; all of the Clark-Kerr campus, block number 7690, to the east city line; all of block number 7680 in the City of Berkeley; portions of block number 1702 in the City of Berkeley. These additional parcels and their assigned street address are established in Section 19.28.030 of the Berkeley Municipal Code, Berkeley Building Code and are specified in Table 4902.1.

Table 4902.1

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Parcels Added to the Berkeley Combined
Hillside District
Parcel Number (APN) Address
048-7680-001-02
048-7680-002-01
048-7680-031-00
048-7680-019-00
048-7680-014-00
048-7680-032-01
048-7680-027-00
054-1702-067-00
054-1702-068-00
054-1702-069-00
054-1702-070-00
054-1702-063-00
054-1702-076-00
054-1702-075-00
054-1702-074-00
054-1702-073-00
054-1702-112-00
054-1702-123-01
054-1702-122-00
054-1702-120-01
054-1702-114-01
054-1702-115-00
054-1702-072-00
054-1702-071-00
054-1702-113-00
054-1702-116-00
3 Tanglewood Road
5 Tanglewood Road
7 Tanglewood Road
11 Tanglewood Road
19 Tanglewood Road
25 Tanglewood Road
29 Tanglewood Road
10 Tanglewood Road
18 Tanglewood Road
22 Tanglewood Road
28 Tanglewood Road
2701 Belrose Avenue
2715 Belrose Avenue
2721 Belrose Avenue
2729 Belrose Avenue
2737 Belrose Avenue
2801 Claremont Boulevard
2811 Claremont Boulevard
2815 Claremont Boulevard
2821 Claremont Boulevard
2816 Claremont Avenue
2820 Claremont Avenue
3005 Garber Street
3015 Garber Street
3020 Garber Street
3017 Avalon Avenue
Fire Zone Two is declared as a Very-High Fire Hazard Severity Zone and Wildland-Urban Interface area.

FIRE ZONE 3 encompasses those areas designated as Environmental Safety - Residential Districts on the Official Zoning Map of the City of Berkeley, as it may be amended from time to time. Fire Zone Three is declared as a Very-High Fire Hazard Severity Zone and Wildland-Urban Interface area.

FIRE ZONE 4 encompasses the area east of Grizzly Peak Boulevard and to the City boundary west, north and south. Fire Zone Four is declared as a Very-High Fire Hazard Severity Zone and Wildland-Urban Interface area.

FIRE-RESISTANT VEGETATION. Plants, shrubs, trees and other vegetation that exhibit properties, such as high moisture content, little accumulation of dead vegetation, and low sap or resin content, that make them less likely to ignite or contribute heat or spread flame in a fire than native vegetation typically found in the region.
[Note: The following sources contain examples of types of vegetation that can be considered fire-resistant vegetation (Fire-resistant Plants for Home

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Landscapes, A Pacific Northwest Extension publication; Home Landscaping for Fire, University of California Division of Agriculture and Natural Resources; Sunset Western Garden Book)].

IGNITION-RESISTANT MATERIAL. A type of building material that complies with the requirements in Section 704A.2 in the California Berkeley Building Code.

LOCAL RESPONSIBILITY AREAS (LRA). Areas of the state in which the financial responsibility of preventing and suppressing fires is the primary responsibility of a city, county, city and county, or district.

STATE RESPONSIBILITY AREA (SRA). Lands that are classified by the Board of Forestry pursuant to Public Resources Code Section 4125 where the financial responsibility of preventing and suppressing wildfires is primarily the responsibility of the state.

WILDFIRE. Any uncontrolled fire spreading through vegetative fuels that threatens to destroy life, property, or resources as defined in Public Resources Code, Sections 4103 and 4104.

WILDFIRE EXPOSURE. One or a combination of radiant heat, convective heat, direct flame contact and burning embers being projected by vegetation fire to a structure and its immediate environment.

WILDLAND-URBAN INTERFACE (WUI). A geographical area identified by the state as a "Fire Hazard Severity Zone" in accordance with the Public Resources Code, Sections 4201 through 4204, and Government Code, Sections 51175 through 51189, or other areas designated by the enforcing agency to be at a significant risk from wildfires. Berkeley Fire Zones 2 and 3 are designated as Wildland-Urban Interface areas. See Government Code Chapter 6.8 Very High Fire Hazard Severity Zones and Public Resources Code Article 9 Fire Hazard Severity Area for the applicable referenced sections.

SECTION 4903 PLANS
Section 4903.3 Submittal, approval and fees. When required to submit a Fire Protection Plan or Vegetation Management Plan for any reason the responsible party shall prepare or cause to be prepared a Fire Protection Plan in accordance with the latest standards of the Berkeley Fire Department. The Fire Protection Plan shall be submitted to, reviewed and approved by the Berkeley Fire Department and shall be enforced and maintained by the responsible party or their designated agent. The Berkeley Fire Department may charge an appropriate fee for the review, approval and processing of the Fire Protection Plan in accordance with the hourly rate established by City Council resolution.

SECTION 4904 FIRE HAZARD SEVERITY ZONES
Section 4904.4 Berkeley Fire Hazard Severity Zones.

FIRE ZONE TWO. Berkeley Fire Zone Two is designated a Very-High Fire Hazard Severity Zone and Wildland-Urban Interface Fire Area. All requirements of Berkeley Fire Code Chapter 49 (with the exception of Section 4907.6), and

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Berkeley Municipal Code Section 19.28.030 (Berkeley Building Code, Chapter 7A) and shall apply.

FIRE ZONE THREE. Berkeley Fire Zone Three is designated a Very-High Fire Hazard Severity Zone and Wildland-Urban Interface Fire Area. All requirements of Berkeley Fire Code Chapter 49 and Berkeley Municipal Code Section

19.28.030, Berkeley Building Code, Chapter 7A shall apply.

FIRE ZONE FOUR. Berkeley Fire Zone Four is designated a Very-High Fire Hazard Severity Zone and Wildland-Urban Interface Fire Area. All requirements of Berkeley Fire Code Chapter 49 and Berkeley Municipal Code Section

19.28.030 (Berkeley Building Code, Chapter 7A) and shall apply.

SECTION 4905 WILDFIRE PROTECTION BUILDING CONSTRUCTION
Section 4905.2 Construction methods and requirements within established limits.

Within the limits established by law, construction methods intended to mitigate wildfire exposure shall comply with the wildfire protection building construction requirements contained in the California Building Standards Code Berkeley Building Code and Berkeley Residential Code, including the following:

1. California Building Code, Chapter 7A.Chapter 7A of the Berkeley Building Code (B.B.C), Berkeley Municipal Code Section 19.28.030.

2. California Residential Code Section R337 of the Berkeley Residential Code (B.R.C.), Berkeley Municipal Code Section 19.29.050.

3. California Referenced Standards Code, Chapter 12-7A.

SECTION 4906 VEGETATION MANAGEMENT
Section 4906.5 Maintenance of existing vegetation. Maintenance and management of existing vegetation shall be in accordance with this Section and with Section 4907, “Defensible Space”.

Section 4906.5.1 Electrical Equipment Support Clearance. Persons owning, controlling, operating or maintaining electrical transmission or distribution lines shall have an approved program in place that identifies poles or towers with equipment and hardware types that have a history of becoming an ignition source, and provides a combustible free space consisting of a clearing of not less than 10 feet (3048 mm) in each direction from the outer circumference of such pole or tower during such periods of time as designated by the fire code official.

Exception: Lines used exclusively as telephone, telegraph, messenger call, alarm transmission or other lines classified as communication circuits by a public utility.

SECTION 4906.5.2 ELECTRICAL DISTRIBUTION AND TRANSMISSION LINE CLEARANCES.

Section 4906.5.2.1 General. Clearances between vegetation and electrical lines shall be in accordance with this section.

Section 4906.5.2.2 Trimming clearance. At the time of trimming, clearances not less than those established by Table 4906.5.2 should be provided. The radial clearances

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shown below are minimum clearances that should be established, at time of trimming, between the vegetation and the energized conductors and associated live parts.

Exception: The fire code official is authorized to establish minimum clearances different than those specified in Table 4906.5.2.2 when evidence substantiating such other clearances is submitted to the fire code official and approved.

TABLE 4906.5.2.2 – MINIMUM CLEARANCES BETWEEN VEGETATION AND

ELECTRICAL LINES AT TIME OF TRIMMING
Line Voltage

MINIMUM RADIAL CLEARANCE
FROM CONDUCTOR (feet)
[x 304.8 mm]
400 – 71,999 4
72,000 – 109,999 6
110,000 – 299,999 10
300,000 or more 15
Section 4906.5.2.3 Minimum clearance to be maintained. Clearances not less than those established by Table 4906.5.2.3 shall be maintained during such periods of time as designated by the fire code official. The site-specific clearance achieved, at time of pruning, shall vary based on species growth rates, the utility company specific trim cycle, the potential line sway due to wind, line sway due to electrical loading and ambient temperature, and the tree’s location in proximity to the high voltage lines.

Exception: The fire code official is authorized to establish minimum clearances different than those specified by Table 4906.5.2.3 when evidence substantiating such other clearances is submitted to the fire code official and approved TABLE 4906.5.2.3 – MINIMUM CLEARANCES BETWEEN VEGETATION AND

ELECTRICAL LINES TO BE MAINTAINED
Line Voltage
MINIMUM CLEARANCE (inches)
[x 25.4 mm]
750 – 34,999 6
35,000 – 59,999 12
60,000 – 114,999 19
115,000 –230,000 30-1/2
Section 4906.5.3 Electrical power line emergencies. During emergencies, the utility company shall perform the required work to the extent necessary to clear the hazard.

An emergency can include situations such as trees falling into power lines, or trees in violation of Table 4906.5.2.3.

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Section 4906.5.4 Correction of Condition. The fire code official is authorized to give notice to the owner of the property on which conditions regulated by Section 4906.5 exist to correct such conditions. If the owner fails to correct such conditions, the City of Berkeley is authorized to cause the same to be done and make the expense of such correction a lien on the property where such condition exists.

Section 4906.5.5 Clearance of Brush or Vegetative Growth from Roadways. The fire code official is authorized to cause areas within 10 feet (3048 mm) from the edge of the pavement on each side of portions of highways, streets and private roads which are improved, designed or ordinarily used for vehicular traffic to be cleared of flammable vegetation and other combustible growth. The fire code official is authorized to enter upon private property to do so.

Exception: Specimens of trees, ornamental shrubbery, or similar plants which are used as ground cover, if they do not form a means of rapidly transmitting fire from the native growth to any building or structure.

Section 4906.6 Unusual Circumstances. If the fire code official determines that difficult terrain, danger of erosion or other unusual circumstances make strict compliance with the clearance of vegetation provisions of Section 4906 undesirable or impractical, enforcement thereof may be suspended and reasonable alternative measures shall be provided.

Section 4906.7 Vegetation and combustible material hazards not otherwise regulated. No person who has any ownership or possessory interest in or control of a parcel of land shall allow to exist thereon any hazardous vegetation or combustible material which constitutes a fire hazard as determined by the Fire Code Official, regardless of the vegetation or material’s proximity to structures.

SECTION 4907 DEFENSIBLE SPACE
Section 4907.4 Specific requirements. Persons owning, leasing, controlling, operating or maintaining buildings or structures in, or upon Wildland-Urban Interface Fire Areas shall at all times comply with the specific requirements set forth within the references listed in Section 4907.3, as well as the following minimum requirements.

Persons owning, leasing or controlling land adjacent to such buildings or structures that are in the Wildland-Urban Interface Fire Area, regardless of the status of their land as developed or undeveloped, shall at all times comply with the specific requirements set forth within the references listed in Section 4907.3, as well as the following minimum requirements. The minimum area(s) of these properties that are required to comply with Section 4907.3 and the following requirements are to be based on a 100-foot distance from structures on all adjacent lands, unless the fire code official determines that compliance with section 4907.4, Item 2 is required.

Property owners are not required or authorized by this code to enter the properties of another person to implement the requirements of this Section. Persons described above shall at all times:

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1. Maintain an effective firebreak by removing and clearing away flammable vegetation and combustible growth from areas within 100 feet of such buildings or structures, but not beyond the property line.

In accordance with Government Code Section 51182, the amount and intensity of fuels management may vary within the 100-foot perimeter of the structure as determined by the inspecting fire department personnel, with more intense fuel reduction being used between 5 and 30 feet around the structure, and an ember-resistant zone being required within 5 feet of the structure based on regulations promulgated by the State Board of Forestry and Fire Protection; and
Exception: Specimens of trees, ornamental shrubbery, or similar plants which are used as ground cover, if they do not form a means of rapidly transmitting fire from the native growth to any building or structure.

2. Maintain additional fire protection or firebreak by removing brush, flammable vegetation and combustible growth located more than 100 feet from such buildings when the fire department determines that conditions exist which may cause a firebreak of 100 feet to be insufficient to provide reasonable fire safety against a wildfire burning under average weather conditions. This section does not require or authorize property owners to manage vegetation beyond their property lines; and.

Exception: Grass and other vegetation, located more than 30 feet (9144 mm) from buildings or structures, and less than four (4) inches (102 mm) in height above the ground need not be removed where necessary to stabilize the soil and prevent erosion.

3. Remove portions of trees which extend within 10 feet (3048 mm) of the outlet of a chimney or stovepipe; and

4. Maintain trees, shrubs and other plants free of dead wood where such plants are adjacent to, below or overhanging a building, windows, or attached decks; and

5. Maintain the roof and gutters of a structure free of leaves, needles or other dead vegetative growth and debris; and

6. Brush and debris do not need to be completely removed, but may be chipped into pieces less than three (3) inches in length, provided that the resulting mulch is less than three (3) inches deep; and

7. The trunks of trees are to be maintained so that they are free of hanging bark and debris to a height of at least eight (8) feet. Where understory vegetation is present hanging bark and debris must be removed to a height equivalent to four times the height of the understory vegetation or eight (8) feet, whichever is greater.

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8. Limb trees and shrubs by removing branches that are within eight feet (8 ft.) of the ground, or four times the height of the understory vegetation, whichever is greater. Where a tree / shrub is not adaptable to limbing to the height described above, use a combination of limbing and/or modify and remove fuels adjacent to and underneath the plant to provide clearance above grade that is equivalent to four times the height of the tallest understory fuel.

9. Relocate wood piles from within 30 feet of structures, or provide an alternative form of protection which will prevent the ignition of the pile or the transmission of fire to a structure.

Section 4907.6 Specific requirements. Effective ENTER DATE (March 1, 2026?) Berkeley Fire Zone 3 and 4 shall be subject to 4907.6 instead of 4907.4:

Performance-Based Approach: While this Section of the code has prescriptive standards that must be met as a baseline, it also adopts a performance-based approach. For situations that are not clearly covered by the prescriptive requirements of this Section, a performance-based approach using methods that are substantiated by evidence-based practices, research, or testing data deemed acceptable by the Fire Code Official may be used. The Fire Code Official reserves the authority to evaluate and approve proposed methods based on their ability to meet the established performance objectives.

This performance-based approach allows for innovation, adaptability, and site-specific solutions while maintaining the primary goal of reducing the ignition hazard to vegetation and structures.

Compliance shall be determined by the demonstrated ability of mitigation measures to meet the performance objectives, below. A variety of techniques, materials, and strategies may be used, provided they effectively achieve the following performance objectives:

1. Maintain defensible space that minimizes the potential that vegetation, debris or other combustible material on a parcel creates a Wildfire Exposure to structures and accessory structures on the property or adjacent properties.

2. Vegetation will be evaluated based on the type, density, configuration, and arrangement on a parcel and how those factors are likely to contribute, or prevent, the spread of fire by radiant heat, ember and direct flame. Each parcel must contribute to the resiliency and reduction of the wildfire hazard the community faces.

Note: Effectiveness of defensible space can be enhanced with improvements to the fire resistance of structures by completing “home hardening” retrofitting that is compliant with California Building Standards Code, including the following:

California Building Code, Chapter 7A, California Residential Code, Section R337, California Referenced Standards Code, Chapter 12-7A, or other features deemed acceptable by the Berkeley Building Official.

Persons owning, leasing, controlling, operating or maintaining buildings or structures in, or upon Wildland-Urban Interface Fire Areas shall at all times

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comply with the specific requirements set forth within the references listed in Section 4907.3, as well as the following minimum requirements.

Persons owning, leasing or controlling land adjacent to such buildings or structures that are in the Wildland-Urban Interface Fire Area, regardless of the status of their land as developed or undeveloped, shall at all times comply with the specific requirements set forth within the references listed in Section 4907.3, as well as the following minimum requirements. The minimum area(s) of these properties that are required to comply with Section 4907.3 and the following requirements are to be based on a 100-foot distance from structures on all adjacent lands, unless the fire code official determines that compliance with section 4907.6, Item 4 (below) is required.

Property owners are not required or authorized by this code to enter the properties of another person to implement the requirements of this Section.

Persons described above shall at all times:

3. Maintain an effective firebreak by removing and clearing away flammable vegetation and combustible growth from areas within 100 feet of such buildings or structures, but not beyond the property line.

In accordance with Government Code Section 51182, the amount and intensity of fuels management may vary within the 100-foot perimeter of the structure as determined by the inspecting fire department personnel, with more intense fuel reduction being used between 5 and 30 feet around the structure, and an ember-resistant zone being required within 5 feet of the structure.

4. Maintain additional fire protection or firebreak by removing brush, flammable vegetation and combustible growth located more than 100 feet from such buildings when the Fire Code Official determines that conditions exist which may cause a firebreak of 100 feet to be insufficient to provide reasonable fire safety against a wildfire burning under average weather conditions. This section does not require or authorize property owners to manage vegetation beyond their property lines.

Exception: Grass and other vegetation located more than 30 feet (9144 mm) from buildings or structures, and less than four (4) inches (102 mm) in height above the ground need not be removed where necessary to stabilize the soil and prevent erosion.

5. Zone 0: The Ember Resistant Zone
D. Maintain all ground areas within five (5) horizonal feet of any structure and any outbuildings, attached decks, stairs, hot tubs and the area under attached decks and stair landings free of combustible material including but not limited to vegetation (including vines), debris, wood mulch products, combustible fencing and gates (e.g.: wood/vinyl), playsets, plastic trash and recycle cans, trellises, pergolas, shade coverings, combustible planters, privacy walls, boats, RVs, vehicles, and other material that could be ignited by embers or direct flame.

Hardscape materials, such as gravel, pavers, concrete, and other noncombustible mulch materials are permitted. This zone extends vertically

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along and above the structure. Sections of trees or large bushes that are within this zone shall be removed unless such work would endanger the health of the tree. Tree limbs not removed shall comply with the remainder of this section.

Exception: Ornamental vegetation maintained in up to 10 small non- combustible planters with plants (no large bushes or trees) that can be easily moved indoors, or outside of Zone 0 on red flag days.

E. Remove all Hazardous Vegetation and Combustible Material capable of being ignited and endangering the Structure or attached deck as determined by the Fire Code Official or their designee.
a. Maintain 6 feet of vertical clearance between branches and all other parts of trees overhanging the roof or other portion of any Structure or attached deck.
b. Maintain any tree, shrub, or other plant adjacent to or overhanging any Structure or attached deck free of branches, dead limbs, or other Combustible Material.
c. Maintain the roof and roof gutters of any structure, and the surface of any attached deck free of leaves, needles, Hazardous Vegetation, and Combustible Materials.
d. Maintain trees to remove Ladder Fuels so that foliage, twigs, or branches are greater than 6 feet above the ground or surface fuels. e. Remove all branches within 10 feet of any chimney or stovepipe outlet. f. Storage of firewood, lumber, or other Combustible Material is not permitted.

6. Zone 1
a. Remove any privacy hedges or rows of bushes that will create a pathway for fire to reach a structure home.
b. Keep low-growing shrubs spaced apart or in small groupings (no more than 3 shrubs or a maximum of 10 feet wide and 10 feet apart from other plantings) that result in a discontinuous path of vegetation. c. If there are multiple structures, such as a shed, hot tub, and playset, ensure these structures are spaced at least 10 feet apart. Have at most three (3) of these structures within 30 feet of your home. d. Relocate exposed firewood piles outside of Zone 1 unless they are completely covered in a fire-resistant material.

7. Zone 2
a. All exposed wood piles must have a minimum of ten feet (10 ft.) of clearance, down to bare mineral soil, in all directions.

8. For both Zones 1 and 2:
a. Remove all flammable vegetation and combustible material capable of transmitting fire to a structure as determined by the Fire Code Official.

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b. Annual grasses must be removed or cut to less than 3 inches. c. Non-irrigated brush is not permitted.
b. Limb trees and shrubs by removing hanging bark, debris and branches that are within eight feet (8 ft.) of the ground, or four times the height of the understory vegetation, whichever is greater. Where a tree / shrub is not adaptable to limbing to the height described above, use a combination of limbing and/or modify and remove fuels adjacent to and underneath the plant to provide clearance above grade that is equivalent to four times the height of the tallest understory fuel. c. Brush and debris does not need to be completely removed, but may be chipped into pieces less than three (3) inches in length, provided that the resulting mulch is less than three (3) inches deep; and d. New trees shall be planted and maintained so that the tree’s drip line at maturity is a minimum of 10 feet from any structure.
e. The horizontal distance between crowns of trees shall not be less than 10 feet.
a. "Outbuildings" and Liquid Propane Gas (LPG) storage tanks shall have the following minimum clearance: ten feet (10 ft.) of clearance to bare mineral soil and no flammable vegetation for an additional ten feet (10 ft.) around their exterior.
b. Protect water quality. Do not clear vegetation to bare mineral soil and avoid the use of heavy equipment in and around streams and seasonal drainages. Vegetation removal can cause soil erosion, especially on steep slopes. Keep soil disturbance to a minimum on steep slopes.

Section 4907.5 Corrective Actions.The fire department is authorized to take enforcement actions as necessary to achieve compliance with Chapter 49 of this code, including but not limited those actions specified in Sections 104.13 (“Authority to arrest and issue citations”), 112.4 (“Violation penalties”) and 114.7 (“Summary abatement”) of this code, and as authorized by Berkeley Municipal Code, Chapter 1.24, “Abatement of Nuisances”, and in accordance with all other applicable portions of the Berkeley Municipal Code. Corrective actions may also include the use of abatement warrants and the imposition of property liens as appropriate and in accordance with law.

Section 4912 SUPPRESSION AND CONTROL OF HAZARDS IN WILDLAND-URBAN INTERFACE AREAS]
Section 4912.1 Permit. The fire code official is authorized to stipulate conditions for permits. Permits shall not be issued when public safety would be at risk, as determined by the fire code official.

Section 4912.2 Restricted Entry. The fire code official shall determine and publicly announce when Wildland-Urban Interface areas shall be closed to entry and when such areas shall again be opened to entry. Entry on and occupation of Wildland-Urban Interface areas, except public roadways, inhabited areas or established trails and camp sites which have not been closed during such time when the Wildland-Urban Interface areas are closed to entry, is prohibited.

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Exceptions:

1. Residents and owners of private property within Wildland-Urban Interface areas and their invitees and guests going to or being upon their lands;

2. Entry, in the course of duty, by peace officers, and other duly authorized public officers, members of a fire department and members of the United States Forest Service
Section 4912.3 Trespassing on Posted Property
Section 4912.3.1 General. When the fire code official determines that a specific area within a Wildland-Urban Interface Areas presents an exceptional and continuing fire danger because of the density of natural growth, difficulty of terrain, proximity to structures or accessibility to the public, such areas shall be closed until changed conditions warrant termination of closure. Such areas shall be posted as hereinafter provided.

Section 4912.3.2 Signs. Approved signs prohibiting entry by unauthorized persons and referring to this section shall be placed on every closed area.

Section 4912.3.3 Trespassing. Entering and remaining within areas closed and posted is prohibited.

Exception: Owners and occupiers of private or public property within closed and posted areas, their guests or invitees, and local, state and federal public officers and their authorized agents acting in the course of duty.

Section 4912.4 Smoking. Lighting, igniting or otherwise setting fire to or smoking tobacco, cigarettes, pipes or cigars in Wildland-Urban Interface areas are prohibited.

Exception: Places of habitation or within the boundaries of established smoking areas or campsites as designated by the fire code official.

Section 4912.5 Spark Arresters. Chimneys used in conjunction with fireplaces, barbecues, incinerators or heating appliances in which solid or liquid fuel is used, upon buildings, structures or premises located within Wildland-Urban Interface areas shall be provided with a spark arrester. See Berkeley Building Code Section 705A.5 for specifications.

Section 4912.6 Tracer Bullets, Tracer Charges, Rockets and Model Aircraft. Tracer bullets and tracer charges shall not be possessed, fired or caused to be fired into or across Wildland-Urban Interface areas. Rockets, model planes, gliders and balloons powered with an engine, propellant or other feature liable to start or cause fire shall not be fired or projected into or across Wildland-Urban Interface Areas.

Section 4912.7 Explosives and Blasting. Explosives shall not be possessed, kept, stored, sold, offered for sale, given away, used, discharged, transported or disposed of within Wildland-Urban Interface areas except by permit from the fire code official.

Section 4912.8 Fireworks. Fireworks shall not be used or possessed in Wildland- Urban Interface areas. The fire code official is authorized to seize, take, remove or cause to be removed fireworks in violation of this section.

Exception: Fireworks allowed by the fire code official under permit when not prohibited by applicable local or state laws, ordinances and regulations.

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Section 4912.9 Apiaries. Lighted and smoldering material shall not be used in connection with smoking bees in or upon Wildland-Urban Interface areas except by permit from the fire code official.

Section 4912.10 Open-Flame Devices. See Berkeley Fire Code Sections 308.1.6 Open Flame Devices and 308.1.6.1 Signals and Markers.

Section 4912.11 Outdoor Fires. Outdoor fires shall not be built, ignited or maintained in or upon Wildland-Urban Interface areas, except by permit from the fire code official.

Exception: Outdoor fires within habited premises or designated campsites, where such fires are built in a permanent barbecue, portable barbecue, outdoor fireplace, incinerator or grill and are a minimum of 30 feet (9144 mm) from a grass-, grain-, brush or forest- covered area.

Permits shall incorporate such terms and conditions, which will reasonably safeguard public safety and property.

Outdoor fires shall be prohibited in or upon Wildland-Urban Interface areas under the following conditions:

1. When red flag conditions exist as defined by the National Oceanic and Atmospheric Administration,

2. When a person age 17 or over is not present at all times to watch and tend such fire, or

3. When public announcement is made that open burning is prohibited.

Permanent barbecues, portable barbecues, outdoor fireplaces, fire pits or grills shall not be used if solid or liquid fueled.

Section 4912.12 Incinerators and Fireplaces. Incinerators, outdoor fireplaces, fire pits, permanent barbecues and grills shall not be built, installed or maintained in Wildland-Urban Interface areas without prior approval of the fire code official. Existing incinerators, outdoor fireplaces, fire pits, permanent barbecues and grills shall be maintained in good repair and in a safe condition at all times. Openings in such appliances shall be provided with an approved spark arrester, screen or door.

Exception: When approved, unprotected openings in barbecues and grills necessary for proper functioning shall be allowed.

Section 4912.13 Dumping. Garbage, cans, bottles, papers, ashes, refuse, trash, rubbish or combustible waste material shall not be placed, deposited or dumped in or upon Wildland-Urban Interface areas or in, upon or along trails, roadways or highways in Wildland-Urban Interface areas.

Exception: Approved public and private dumping areas.

Section 4912.14 Disposal of Ashes. Ashes and coals shall not be placed, deposited or dumped in or upon Wildland-Urban Interface areas.

Exceptions:

1. In the hearth of an established fire pit, camp stove or fireplace;

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2. In a noncombustible container with a tight-fitting lid, which is kept or maintained in a safe location not less than 10 feet (3048mm) from combustible vegetation or structures;

3. Where such ashes or coals are buried and covered with 1 foot (304.8mm) of mineral earth not less than 25 feet (7620 mm) from combustible vegetation or structures.

Section 4912.15 Use of Fire Roads and Firebreaks. Motorcycles, motor scooters and motor vehicles shall not be driven or parked upon, and trespassing is prohibited upon, fire roads or firebreaks beyond the point where travel is restricted by a cable, gate or sign, without the permission of the property owner(s). Vehicles shall not be parked in a manner, which obstructs the entrance to a fire road or firebreak.

Exception: Public officers acting within their scope of duty. Radio and television aerials, guy wires thereto, and other obstructions shall not be installed or maintained on fire roads or fire breaks unless located 16 feet (4877 mm) or more above such fire road or firebreak.

Section 4912.16 Use of Motorcycles, Motor Scooters and Motor Vehicles.

Motorcycles, motor scooters and motor vehicles shall not be operated within Wildland- Urban Interface areas, without a permit by the fire code official, except upon clearly established public or private roads. Permission from the property owner(s) shall be presented when requesting a permit.

Section 4912.17 Tampering with Fire Department Locks, Barricades and Signs.

Locks, barricades, seals, cables, signs and markers installed within Wildland-Urban Interface areas, by or under the control of the fire code official, shall not be tampered with, mutilated, destroyed or removed. Gates, doors, barriers and locks installed by or under the control of the fire code official shall not be unlocked.

Section 4912.18 Liability for Damage. The expenses of fighting fires and securing emergencies, which result from a violation of this code, Chapter 6.15.030 of the Berkeley Municipal Code (“Unauthorized barbecues and fire on public property”), Sections 13000-13011 of the California Health and Safety Code, Sections 4421-4446 of the California Public Resources Code, or Sections 451, 451.5, 452 or 455 of the California Penal Code is a charge against the person(s) whose violation of the code section(s) caused the fire. Damages caused by such fires shall constitute a debt of such person(s) and shall be collectable by the fire code official in accordance with Section 107.7 of the BMC.

Chapter 50 of the California Fire Code is adopted in its entirety subject to the modifications thereto which are set forth below.

CHAPTER 50 – HAZARDOUS MATERIALS – GENERAL PROVISIONS
SECTION 5001 GENERAL
Section 5001.7 Hazardous materials transportation restrictions. No vehicle containing hazardous materials, including a hazardous materials transportation tank truck, trailer, semi-trailer or tank wagon containing flammable or combustible liquids,

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hazardous chemicals, liquefied petroleum gases, poisonous gases, or cryogenic fluids, shall be operated on any city street without a permit from the fire code official. A map showing the proposed route of the vehicle shall accompany applications for such permits. If a permit is granted, the map shall be carried at all times in the vehicle and the vehicle shall not deviate from the approved route as shown on the map. Such a permit may contain conditions, including restrictions on the hours within which certain routes may be used and limitations on the size of the vehicle allowed to travel the approved route. No route shall be approved that includes passage over or adjacent to subway entry or vent structures, through the Northbrae Tunnel, in any area designated an environmental safety residential district by the City of Berkeley's Zoning Ordinance, or in an area which may be designated as a hazardous fire area. Departure from the approved route, travel outside the permitted hours, and violation of any vehicle size limitation imposed, or failure to carry a map showing route approval shall constitute a violation of this Code. The transportation of extremely hazardous materials may, in the discretion of the fire code official, require both a permit and accompaniment by a Fire Department or Police Department convoy. The following streets contain purge chamber openings which lead directly into the subway section of the Bay Area Rapid Transit (BART) System in Berkeley and their use by tank vehicles or trailers for transportation or delivery of flammable or combustible liquids, hazardous chemicals, liquefied petroleum gases, poisonous gases, or cryogenic fluids is prohibited and a violation of this Code:
a. On Addison Street between Martin Luther King Jr. Way and Oxford Street; b. On Shattuck Avenue between University Avenue and Dwight Way; c. On Virginia Street between Franklin and Sacramento Streets; d. On Sacramento Street between Virginia Street and Hearst Avenue; e. On Hearst Avenue between McGee Avenue and Milvia Street; f. On Adeline Street between Ward and Stuart Streets; and g. On Adeline Street between Ashby Avenue and Woolsey Street CHAPTER 56 – EXPLOSIVES AND FIREWORKS
SECTION 5601 GENERAL
5601.1.3 Fireworks. The possession, manufacture, storage, sale, handling and use of fireworks, including fireworks which are classified as Safe and Sane fireworks by the California State Fire Marshal’s Office, are prohibited within the City of Berkeley.

Exceptions:

1. Storage and handling of fireworks as allowed in Section 5604.

2. Manufacture, assembly and testing of fireworks as allowed in Section 5605 and Health and Safety Code Division 11.

31. The use of fireworks for fireworks displays, pyrotechnics before a proximate audience and pyrotechnic special effects in motion pictures, television, theatrical or group entertainment productions as allowed in Title 19, Division 1, Chapter 6 Fireworks reprinted in Section 5608 and Health and Safety Code

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Division 11 when stored, transported, handled and used under the required fire department permit(s) and in accordance will all applicable requirements of Chapter 56.

42. The possession, storage, sale, handling and use of specific types of Division

1.4G fireworks where allowed by applicable laws, ordinances and regulations, provided that such fireworks and facilities comply with NFPA 1124, CPSC 16 CFR Parts 1500 and 1507, and DOTn 49 CFR Parts 100– 185, as applicable for consumer fireworks and Health and Safety Code Division 11.

Section 5604.1 General. The storage and handling of explosives within City of Berkeley limits is prohibited. Storage of explosives and explosive materials, small arms ammunition, small arms primers, propellant- actuated cartridges and smokeless propellants in magazines shall comply with the provisions of this section Exception: Where expressly permitted by applicable laws, ordinances or regulations provided such storage and handling of explosives and explosive materials, small arms ammunition, small arms primers, propellant-actuated cartridges and smokeless propellants in magazines is conducted in accordance with Section 5604 and all applicable provisions of Chapter 56.

CHAPTER 57 – FLAMMABLE AND COMBUSTABLE LIQUIDS
SECTION 5701 GENERAL
Section 5701.4.1 Transfer of flammable and combustible liquids. Transfer to or from containers or mobile tanks, above ground or underground tanks of flammable and combustible liquids shall not be made from or on the street or public way except by written approval by the fire code official.

Exceptions:

1. Transfer of not more than 5 gallons flammable or combustible liquids using a listed or approved portable fuel container of not more than 5 gallons capacity.

2. The transfer of combustible liquids to or from approved, fixed mechanical or electrical system equipment such as a Standby or Emergency electric power generator when the transfer is completed by a commercial fuel vendor using approved dispensing equipment via a previously approved, fixed tank filling port which met code requirements at the time of installation.

SECTION 5704 STORAGE
Section 5704.2.11.1.1 Restrictions on underground storage tanks. The storage of flammable and combustible liquids in underground tanks is prohibited in all areas zoned solely for residential occupancies, closely built commercial properties, and any other area deemed unsafe by the fire code official.

Section 5704.2.13.1.4 Tanks abandoned in place. Tanks may be abandoned only under permit and following City of Berkeley Fire Department procedures. The owner shall demonstrate to the satisfaction of the City of Berkeley Toxics Management Division (TMD) that no unauthorized release has occurred. If the soil is contaminated, mitigation must be completed to the satisfaction of the Toxics Management Division (TMD). A notice shall be placed in the deed to the property. This notice shall describe

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the precise location of the closed underground storage tank, the hazardous substances that it contained, and the closure method. Tanks abandoned in place shall be as follows:

1. Flammable and combustible liquids shall be removed from the tank and connected piping.

2. The suction, inlet, gauge, vapor return and vapor lines shall be disconnected.

3. The tank shall be filled completely with an approved inert solid material.

4. Remaining underground piping shall be capped or plugged.

5. A record of tank size, location and date of abandonment shall be retained.

6. All exterior above-grade fill piping shall be permanently removed when tanks are abandoned or removed.

Section 5704.2.14 Removal and disposal of tanks. Removal and disposal of tanks shall comply with Sections 5704.2.14.1 and 5704.2.14.2. Removal of all tanks shall be authorized under a fire permit, abiding by City of Berkeley Fire Department procedures.

The applicant shall submit the following:

1. A site plan showing the location of the tanks.

2. A detailed description of the scope of work.

3. A site safety plan.

4. A vicinity map to the closest hospital, in an event of an emergency.

5. Proof of workers compensation insurance.

The owner shall demonstrate to the satisfaction of the City of Berkeley Toxics Division that no unauthorized release has occurred. If the soil is contaminated, mitigation must be completed to the satisfaction of the Toxics Division or the California Water Board.

CHAPTER 61 – LIQUIFIED PETROLEUM GASES
SECTION 6104 LOCATION OF LP-GAS CONTAINERS
Section 6104.1.1 Restrictions on storage of LP-gas containers. It shall be unlawful to store any liquefied petroleum gas cylinder with a capacity greater than 2-1/2 lbs. water capacity or a portable tank within any structure or building with an occupancy classification of A, R-1, R-2 or R-4, unless specifically authorized by this Code.

APPENDIX B – FIRE FLOW REQUIREMENTS FOR BUILDINGS
Section B105.2 (Appendix B), Table B105.2, “Required Fire-Flow for Buildings Other Than One- And Two-Family Dwellings, Group R-3 And R-4 Buildings And Townhouses” [Amended Table]
TABLE B105.2
REQUIRED FIRE·FLOW FOR BUILDINGS
OTHER THAN ONE· AND

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TWO-FAMILY DWELLINGS, GROUP R·3 AND R·4

BUILDINGS AND TOWNHOUSES

AUTOMATIC SPRINKLER
SYSTEM
(Design Standard)

MINIMUM FIRE-FLOW
(gallons per minute)

FLOW DURATION
(hours)
No automatic sprinkler system Value in Table B105.1(2) Duration in Table B105.1(2) Section 903.3.1.1 of the
California Fire Code
2550% of the value in
Table B105.1(2)a
Duration in Table Bl 05.1(2) at the
reduced flow rate
Section 903.3.1.2 of the
California Fire Code
2550% of the value in
Table B105.1(2)b
Duration in Table Bl05.1(2) at the
reduced flow rate
For SI: 1 gallon per minute= 3.785 Lim.
a. The reduced fire-flow shall be not less than 1,000 gallons per minute. b. The reduced fire-flow shall be not less than 1,500 gallons per minute.

APPENDIX L – REQUIREMENTS FOR FIRE FIGHTER AIR REPLENISHMENT

SYSTEMS
SECTION L104 DESIGN AND INSTALLATION
Section L104.5.1 Stored pressure air supply. A stored pressure air supply shall be designed based on Appendix Chapter F of the California Plumbing Code Chapter 24 of NFPA 1901 except that the provisions applicable only to mobile apparatus or not applicable to system design shall not apply. A stored pressure air supply shall store not less than 5,000 Standard Cubic Feet (SCF) of air or be capable of refilling not less than 50 empty breathing air cylinders of a size and pressure used by the fire department, whichever is greater.

Section 19.48.030 Validity. Should any section, paragraph, sentence or word of this Chapter or of the Code or Standards be declared invalid, all other portions of this Chapter shall remain in effect.

Section 2. Copies of this Ordinance shall be posted for two days prior to adoption in the display case located near the walkway in front of the Maudelle Shirek Building, 2134 Martin Luther King Jr. Way. Within 15 days of adoption, copies of this Ordinance shall be filed at each branch of the Berkeley Public Library and the title shall be published in a newspaper of general circulation.

Safer from Wildfires was created by an interagency partnership between Insurance Commissioner Ricardo Lara and the emergency response and readiness agencies in Governor Gavin Newsom's administration. Learn more at insurance. ca.gov
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• Class A fire-rated roof
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Clear the first 5 feet
Removing greenery and replacing wood
chips with stone or decomposed granite
5 feet around your home prevents fire
from getting a foot in the door.

Scan to find more resources
Keep embers out
Installing 1/16 to 1/8 inch
noncombustible, c
orrosion-resistant metal
mesh screens over attic vents can keep
wind-blown embers out of your house.

To apply for a designation certificate or learn more visit wildfireprepared.org.

How-To Prepare Your Home Checklist- August 2023
3 How-to Prepare Your Home Checklist
Wildfire Prepared Home Base Designation
Typically achieved through retrofits to existing homes —This group of required actions includes creating a 5-foot noncombustible home buffer, preparing the home’s exterior, and maintaining the deck/covered porch and yard. To receive a designation certificate, your home must meet all requirements listed for this level.

CREATE A 5-FOOT HOME BUFFER (0-5 FEET)

1. Create a 5-foot noncombustible buffer around your home and decks. ☐ Remove ALL vegetation and combustible ground covers such as wood mulch within 5 feet of your home. This means all bushes, grass/artificial turf, flowers, trees, succulents, etc., down to bare dirt or hardscape. ☐ Remove trees and trim branches that overhang the 5-foot area; the home buffer extends to the sky. Don’t forget your deck too.
☐ Install hardscape: Clear the 5 feet around your home including decks/covered porches, under and around the stairs to bare dirt. You may also, use hardscapes such as gravel, pavers, river rocks, DG base, steppingstones, or concrete to create an attractive noncombustible buffer zone. ☐ Replace combustible (wood/vinyl) fencing, posts, and gates within 5 feet of the home with a noncombustible fence, such as metal (aluminum, chain link, or iron) or concrete blocks.
☐ Remove vines from the home, pergolas, fences, and within 5 feet. ☐ Clear and maintain the 5-foot noncombustible buffer area. • Clear tree debris, weeds, leaves, and grass regularly. • Do not park or store any vehicles, boats, RVs, trailers, or ATVs within 5 feet of the home. Ideally, relocate these stored items in a closed garage or park them at least 30 feet away from the home. • Remove all combustible items such as firewood, potted plants, outdoor furniture, trash cans, pet houses, lawn tools, sheds, hot tubs, etc., from this zone.

PREPARE YOUR HOME’S EXTERIOR

2. Check and maintain your roof and gutters.
☐ Clear all tree debris from your roof and gutters regularly. ☐ Replace a wood shake/shingle roof with a Class A fire-rated roof cover such as asphalt shingles, tile, slate, or metal. Barrel tile and some metal must also include bird stops at the edges, to prevent intrusion under the tile by birds or other wildlife.
☐ Replace plastic/vinyl gutters and downspouts with metal.

3. Ensure a 6-inch vertical clearance on exterior walls. ☐ Ensure there is a minimum of 6 vertical inches (measured from the ground up and from any attached horizontal surface like a deck) of noncombustible siding material around your home. This can include fiber-cement, brick, stone, stucco, or exposed concrete foundation. Additionally, metal flashing can be used above deck walking surfaces and posts.
5-foot Home Buffer Tips:
o Use a measuring tape from the base of the walls and deck to measure out to 5 feet. If you have a covered porch, it should be measured out to 5 feet from the cover, including vertical supports. o Homeowners with less than 5-feet of setback will have to work with neighbor(s) to create and maintain the 5-foot buffer zone.

Wood and vinyl fences
when ignited can
provide a pathway for
fire to reach your home.
6-inch clearance: Embers
accumulate against
homes at the base of
exterior walls and on other
horizontal surfaces like
decks that can ignite the
home.

During a wildfire, embers
can travel miles ahead
of a fire front and
accumulate at the base
of your home’s exterior
walls and within the first
5 feet. By implementing
a 5-foot
noncombustible buffer
zone, you significantly
reduce the chances of
your home being ignited
by wildfire.

To apply for a designation certificate or learn more visit wildfireprepared.org.

How-To Prepare Your Home Checklist- August 2023
4 4. Install ember-resistant vents.
☐ Install ember-resistant vents or cover all existing vents with 1/8-inch metal wire mesh.
☐ Ensure your dryer vent has working louvers or a flap to reduce ember entry. Due to its design and function, wire mesh should not be used on dryer vents.

Note: Plumbing vents are excluded from these requirements.

MAINTAIN DECKS & YARD (5-30 FEET)

5. Clear and maintain decks and covered porches.

On the surface of a deck, patio, or under a covered porch:
☐ Clear all tree debris regularly.
☐ Remove large rugs and combustible furniture such as wood, wicker, or plastic. Use noncombustible cast aluminum or metal furniture instead. ☐ Ensure if you have a few small items, they can easily be moved inside on Red Flag days and keep them out of the 5-foot buffer.
o You may have up to 10 small, noncombustible terra cotta or ceramic planters with small flowers or plants; avoid woody vegetation or trees in the pots.
o You may have a few cushions and a small door mat.
☐ Remove combustible structures such as a pergola or gazebo from wood or composite decks. You may replace it with a noncombustible material such as metal.
☐ Retrofit vinyl/wood pergolas within 30 feet with all the following:
o Place pergola on a noncombustible surface and include the surrounding 5-foot noncombustible buffer.
o Remove 50% of the slats or cover the roof with a Class A material such as metal or asphalt shingles.
o Install 6 inches of noncombustible siding material to the bottom of the posts where they meet the ground. Materials can include metal flashing, concrete block, fiber cement siding, or stone/brick veneer.
☐ Remove all accessories from the structures such as hanging plants, vines, and any curtains/drapes/ screens.
☐ Remove hot tubs from underneath a covered porch and from combustible (wood or composite) decks. Place hot tubs to at least 10 feet away from the home if located on a noncombustible patio material such as stones, pavers, or concrete. Ensure it includes the surrounding 5-foot noncombustible buffer and 6 vertical inches of noncombustible material such as flashing.

Note: Detached decks, covered porches, and pergolas within 30 feet of the home must meet the same requirements as attached decks.

Underneath the walking surface of a deck:
☐ Remove anything stored under the deck or stairs.
☐ Remove all vegetation—including grass or weeds—from under the deck and stairs.

Wind-blown embers can
enter your home through
vents in your attic, roof,
gables, and crawlspace
and ignite materials
inside.

Decks attached to or built
near your home provide a
path for fire to reach your
home. Reducing or
eliminating the
vulnerabilities of a deck or
porch—including items on
top of or underneath—
reduces the chance your
home ignites.

Vent Tips
o Check your current vent mesh size using a golf tee or the tip of a pen. If the tee does not fit through the mesh openings, it is the correct size. o You can cover your current vents by installing the 1/8-inch metal mesh from the inside or outside.

To apply for a designation certificate or learn more visit wildfireprepared.org.

How-To Prepare Your Home Checklist- August 2023
5 ☐ Install 6 inches of noncombustible siding material to the bottom of the posts where they meet the ground.
☐ Include a 5-foot noncombustible buffer around deck and stairs. ☐ Additionally, for decks with a walking surface at a height of 4 feet or less from the ground, enclose the area underneath with one of the following:
• Install 1/8-inch or finer metal wire mesh around the outer edge of the walking surface extending to the ground, or
• Install a noncombustible wall covering.

6. Maintain the yard, trees, and structures from 5 to 30 feet. ☐ Maintain the yard
• Cut grass to no more than 4 inches and keep watered.
• Routinely clear tree debris such as leaves and pine needles. • Remove dead vegetation, including piles from pruning. Firewood should be stored 30 feet from any structures.
☐ Trim trees
• Remove tree limbs less than 6 feet from the ground.
• Trim upper branches of trees to ensure at least 10 feet of space between the canopies of neighboring trees.
☐ Maintain shrubs
• Choose low-growing, fire-resistant plants.
• Relocate any shrubs located under or near trees.
• Keep low-growing shrubs spaced apart or in small groupings (no more than 3 shrubs or a maximum of 10 feet wide and 10 feet apart from other plantings) that will result in a discontinuous path of vegetation.
• Remove any privacy hedges or rows of bushes that will create more fuel and a pathway for fire to reach your home.
☐ Maintain structures within 30 feet of your home (i.e., sheds, hot tubs, pergolas, and playsets)
• Place structures at least 10 feet away from the home or any attached decks.
• Create a 5-foot noncombustible buffer around and under each structure.
• Clear all vegetation such as vines growing on and tree branches overhanging these structures.
• Ensure there is a minimum of 6 vertical inches (measured from the ground) of noncombustible siding material at the base of each structure or any horizontal surfaces, such as a hot tub, just as you would for your home. For an elevated structure like a shed, enclose the base with no larger than 1/8-inch or finer metal wire mesh. • If you have multiple structures, such as a shed, hot tub, and playset, ensure these structures are spaced at least 10 feet apart. Have at most 3 of these structures within 30 feet of your home.
• Move large stationary propane tanks to 30 feet away from the home. If there is not an option to move the tank 30 feet from your home, it should be placed a minimum of 10 feet from the home and one of the following:
• Buried underground.
• Enclosed on all 4 sides with concrete block, 1/8-inch mesh over the top for ventilation, and 5-feet of noncombustible groundcover surrounding the structure.* *This is a suggestion, retrofit in coordination with your propane provider.

Note: Best practice is to place structures 30+ feet away from your home. To meet the Plus level designation, it is required to have all structures placed at least 30 feet from the home.

Embers blown from
miles away can
easily start spot fires
around your home.

Creating and
maintaining
defensible space on
your property will
slow the spread of
fire and reduce
flame intensity near
your home. By
spacing out bushes
and trees, you are
removing ladder
fuels that allow fire
to spread and
reducing the
intensity of a fire
near your home.

For low decks, enclose
the area underneath to
keep debris and
embers out which can
easily ignite a deck
from underneath.

Office of the City Manager
2180 Milvia Street, Berkeley, CA 94704 ● Tel: (510) 981-7000 ● TDD: (510) 981-6903 ● Fax: (510) 981-7099 E-Mail: [email protected] Website: https://berkeleyca.gov/

ACTION CALENDAR
February 11, 2025
To: Honorable Mayor and Members of the City Council
From: Paul Buddenhagen, City Manager
Submitted by:

David Sprague, Fire Chief
Subject: Effective Mitigations for Berkeley’s Ember Resilience (EMBER): Building Code Amendments

RECOMMENDATION
Staff will return to Council by the end of 2025 with a resolution for the triannual adoption of the existing Berkeley Building, Historical and Fire Codes that will be applicable to Berkeley Fire Zone 3 and 4. These amendments to the 2025 California Building Standards will strengthen defenses against ignition of structures from embers, radiant heat and direct flame impingement during wildfire. Staff seeks Council’s input on this proposal and plan to return to Council at the end of 2025 with a resolution proposed for adoption that incorporates the Council’s feedback.

The amendments may include but are not limited to requiring Class A roofs during partial replacement of non-compliant roof and roof structures, requiring replacement of combustible siding with California Building Code (CBC) Chapter 7A compliant siding during partial replacements, installation of metal gutters and screens, installation of Chapter 7A compliant vents or vent screens, replacement of combustible decks and fences with Chapter 7A compliant materials and design during partial replacement, and six inches of vertical separation measured from the ground to any combustible siding.

Because of the fiscal impact that some of this work will have for homeowners, staff plans to investigate Federal, State or Municipal programs that would provide incentives and loans for improvements to existing non-compliant homes that focus on the highest priority items, such as roof material, siding, decks, ember resistant vents, and a 6” vertical separation between the siding and the ground at the base of a home near the foundation.

FISCAL IMPACTS OF RECOMMENDATION
A considerable amount of staff time will be required to research and draft these code amendments. There may also be additional revenue resulting from modifications to the code that require additional or more expansive building and fire permits.

EMBER: Building Code Amendments WORKSESSION
February 11, 2025

CURRENT SITUATION AND ITS EFFECTS
Chapter 7A of the California Building Code sets fire-resistant construction requirements for buildings in wildfire-prone areas, focusing on materials and designs that reduce the risk of ignition from direct flame, radiant heat and embers.

Compliance with Chapter 7A – especially when coupled with code compliant defensible space - has been shown to significantly increase structure survival rates and would be necessary for a parcel to achieve full protection from direct flame, radiant heat and embers. Chapter 7A requires construction features such as Class A non-combustible roof assemblies, double-pane windows, ember-resistant vents, gutter guards, non- combustible exterior walls, under-floor protection such as gypsum sheathing, and decks made from approved non-combustible material. Retroactive enforcement of Chapter 7A of the Building Code would be ideal but is not legally possible and would create a substantial burden on residents. It is important to note that Chapter 7A is designed to work in concert with, and not as a substitute for, defensible space recommendations proposed within the EMBER initiative.

The State already mandates that new homes built in a Very High Fire Hazard Severity Zone meet the requirements of Chapter 7A. However, only 50 homes in Berkeley’s Very High Fire Hazard Severity Zone, and around 10 in the proposed Fire Zone 4, were built since these code changes went into effect in 2008. Given this reality, the challenge to the community is how to “harden” the ignition prone, pre-2008 constructed homes so there is a contiguous buffer of homes that will resist ignition as a neighborhood.

Further, some structures in the Very High Fire Hazard Severity Zone still have wood shake roofs. Under the current code, homeowners are permitted to repair up to 50% of a wood shake roof (over a five-year period). In the 1991 Oakland-Berkeley Hills Fire, it was estimated that each burning home with a wood shake roof contributed to the ignition of ten other homes1. This analysis will include a recommendation to close this loophole and require that a wood shake roof be entirely replaced when any portion of it requires replacement. In our region, San Rafael2 has adopted a similar measure.

BACKGROUND AND DISCUSSION
New construction in Berkeley Fire Zone 2 and 3 is already required to be compliant with California Building Code (CBC) Chapter 7A. Chapter 7A requires measures such as Class A non-combustible roofs, double-pane windows, ember-resistant vents, gutter guards, non-combustible exterior walls, under-floor protection such as gypsum sheeting, and decks made from approved non-combustible material. However, only approximately 1 Bryner, 2000
2 https://www.cityofsanrafael.org/question/shake-and-wooden-roofs-are- prohibited/#:~:text=Following%20City%20Council%20action%20in,replaced%20by%20May%2031%2C% 202027.

EMBER: Building Code Amendments WORKSESSION
February 11, 2025

50 homes in the current CalFIRE Very High Fire Hazard Severity Zone and approximately 10 homes within the new proposed Berkeley Zone 4 were built since these code changes went into effect in 2008. The challenge to the community is how to “harden” the ignition prone, pre-2008 constructed homes.

By focusing education, incentives, and enforcement on these adjoining properties we can achieve network effects and create a wildfire buffer. Contiguous properties that implement the scientifically validated best practices described above will form a resilient unit, rather than a scattered, salt-and-pepper approach with some mitigated properties surrounded by those with unmitigated hazards. Post-incident analysis of the Camp Fire in Paradise shows that, had the town of Paradise met the parameters that follow, a 53% reduction (minimally) in loss would have occurred.

ENVIRONMENTAL SUSTAINABILITY AND CLIMATE IMPACTS
Wildfires that transition to a structure-to-structure conflagration have acute and far- reaching consequences, not only for the environment and climate but also for the stability and well-being of impacted communities. These fires release large amounts of pollutants into the air, including soot and carbon dioxide, which contribute to climate change and degrade air quality. Additionally, toxic byproducts from burning structures, vehicles, and other synthetic material can pose significant health risks to residents and responders.

The water used to combat these fires is often sourced from the city's potable water supply. Once used, it can become contaminated with chemicals, ash, and debris, potentially polluting groundwater and local waterways.

The destruction of homes, businesses, and critical infrastructure leads to substantial economic burdens that jeopardize the financial stability of impacted communities.

Rebuilding efforts require significant financial investment, as well as the production, transportation, and installation of new materials—all of which generate additional emissions. For individual residents, the loss of a home or business can lead to long- term financial instability, displacement, and increased insurance costs.

Beyond the physical and financial toll, these disasters leave lasting emotional and psychological scars on affected communities. Residents may experience trauma, anxiety, and grief, particularly when lives are lost, homes are destroyed, or neighborhoods are permanently altered. The social fabric of a community can be disrupted as families and businesses struggle to recover, sometimes forcing relocation and reducing neighborhood cohesion.

Investing in a strong fire code is one tool the city uses to reduce the frequency and severity of fires. Effective fire prevention also contributes to environmental sustainability by reducing emissions, preserving water resources, and minimizing the need for costly rebuilding efforts. A commitment to strong fire safety regulations ultimately benefits the entire community—protecting public health, safeguarding financial resources, and ensuring a resilient and sustainable future.

EMBER: Building Code Amendments WORKSESSION
February 11, 2025

RATIONALE FOR RECOMMENDATION
The fire and seismic danger and other local conditions justify the research and potential local amendments that are stricter than the California Building Code.

CONSIDERATIONS FOR COUNCIL
We live in a fire dependent landscape and it is inevitable that a wildfire will impact the city again.

So, the question is, if not this, then what? All the home hardening mitigation measures described in this staff report, along with Zone 0 must be implemented on a sufficient number of contiguous parcels in a neighborhood for the wildfire hazard to be meaningfully reduced. Doing anything less has been validated to be almost meaningless with regard of hazard reduction.

If we are unwilling or unable to move forward with EMBER, then the best use of our wildfire funds may be to continue to prepare to move residents out of the way of a fast- moving wildfire and prepare for substantially greater loss and the burden of rebuilding.

CONTACT PERSON
David Sprague, Fire Chief, 510-981-3473[Phone Number]
Attachments:
1: California Department of Insurance Safer from Wildfire Standard[Title or Description of Attachment]
2: IBHS Wildland Fire Embers and Flames: Home Mitigations That Matter

RESOLUTION NO. ##,###-N.S.

EMBER: BUILDING CODE AMENDMENTS
WHEREAS, enacted in 2008, Chapter 7A of the California Building Code sets fire- resistant construction requirements “home hardening” for buildings in wildfire-prone areas, focusing on materials and designs that reduce the risk of ignition from direct flame, radiant heat and embers, and
WHEREAS, home hardening is designed to work in concert with, and not as a substitute for, defensible space, including Zone 0, and
WHEREAS, the State already mandates that new homes built in a Very High Fire Hazard Severity Zone meet the requirements of Chapter 7A. However, only 50 homes in Berkeley’s Very High Fire Hazard Severity Zone, and
WHEREAS, in the 1991 Oakland-Berkeley Hills Fire, it was estimated that each burning home with a wood shake roof contributed to the ignition of ten other homes, and WHEREAS, the challenge to the community is how to “harden” the ignition prone, pre- 2008 constructed homes so there is a contiguous buffer of homes that will resist ignition as a neighborhood.

NOW THEREFORE, BE IT RESOLVED that the Council of the City of Berkeley adopts a resolution directing the City Manager to research and propose amendments to the existing Berkeley Building, Historical and Fire Codes in the next triannual code adoption process adopting amendments to the 2025 California Building Standards that will strengthen defenses against ignition of structures from embers, radiant heat and direct flame impingement during a wildfire.

BE IT FURTHER RESOLVED that these amendments may include but are not limited to requiring Class A roofs during partial replacement of non-compliant roof and roof structures, requiring replacement of combustible siding with California Building Code (CBC) Chapter 7A compliant siding during partial replacements, installation of metal gutters and screens, installation of Chapter 7A compliant vents or vent screen, replacement of combustible decks and fences with Chapter 7A compliant materials and design during partial replacement, and six inches of vertical separation measured from the ground to any combustible siding.

BE IT FURTHER RESOLVED that due to the fiscal impact that some of this work will have for homeowners, the City Manager will investigate Federal, State or Municipal programs that would provide incentives and loans for improvements to existing non- compliant homes that focus on the highest priority items, such as roof material, siding, decks, ember resistant vents, and a 6” vertical separation between the siding and the ground at the base of a home near the foundation.

February 11, 2025

Safer from Wildfires was created by an interagency partnership between Insurance Commissioner Ricardo Lara and the emergency response and readiness agencies in Governor Gavin Newsom's administration. Learn more at insur ance.ca.gov
Safer from Wildfires is a ground-up approach to wildfire resilience with three layers of protection — for the structure, the immediate surroundings, and the community. Following these achievable steps can help you save money on your insurance.

Protect your home
or business
Protect the
whole community
Protect the
immediate surroundings
Safer from Wildfires
Being
Can Help With Your Insurance

Do more, save more
Every action under Safer from Wildfires will qualify you for an insurance discount.

By doing more, you can save more.
• Class A fire-rated roof
• 5-foot ember-resistant zone around the structure
• Noncombustible 6 inches at the bottom of walls
• Ember- and fire-resistant vents
• Double pane windows or added shutters
• Enclosed eaves
• Cleared vegetation and debris from under decks
• Move sheds and outbuildings at least 30 feet away
• Trim trees and remove brush in compliance with state and local defensible space laws • Neighborhoods can form a Firewise USA community
• Cities, counties, and local districts can become certified as a Fire Risk Reduction Community 3 Ways to Get Started with Safer from Wildfires
Don’t know where to start? Here are 3 low-cost steps you can take today.

Be safer together
With Firewise USA, communities as
small as 8 dwelling units or as big as
2,500 can create an action plan and
start being safer together. Firewise USA
is a nationally recognized program
with proven results, sponsored by the
National Fire Prevention Association.

Clear the first 5 feet
Removing greenery and replacing wood
chips with stone or decomposed granite
5 feet around your home prevents fire
from getting a foot in the door.

Scan to find more resources
Keep embers out
Installing 1/16 to 1/8 inch
noncombustible
, corrosion-resistant metal
mesh screens over attic vents can keep
wind-blown embers out of your house.

1 IBHS RESEARCH
WILDLAND FIRE EMBERS AND FLAMES:

Home Mitigations That Matter
Faraz Hedayati, PhD
Stephen L. Quarles, PhD
Steven Hawks
April 2023

2 Contents
Contents .......................................................................................................................................................................................................................................... 2 Executive Summary .............................................................................................................................................................................................................. 3 Mitigations Against Embers and Flames ..................................................................................................................................................... 3 Wildfire Mitigation Issues in Brief.............................................................................................................................................................................. 5 Mechanisms of Ignition ..................................................................................................................................................................................................... 6 Mitigations That Matter ..................................................................................................................................................................................................... 7 Roof ............................................................................................................................................................................................................................................... 7 Gutters and Downspouts ...........................................................................................................................................................................................8 Vents .......................................................................................................................................................................................................................................... 10 Vertical Ground Clearance ....................................................................................................................................................................................... 11 Fuel Management in Zone 0 ................................................................................................................................................................................ 13 Vegetation in Zone 0................................................................................................................................................................................................. 14 Fences in Zone 0 ........................................................................................................................................................................................................... 16 Attached Decks ............................................................................................................................................................................................................. 17 Fuel Management Beyond Zone 0 ................................................................................................................................................................. 18 Vegetation Beyond Zone 0.................................................................................................................................................................................. 18 Accessory Structures and Outbuildings ................................................................................................................................................... 19 Fences Outside of Zone 0 ..................................................................................................................................................................................... 21 Eaves and Soffits ............................................................................................................................................................................................................. 22 Exterior Wall Covering/Cladding ...................................................................................................................................................................... 23 Exterior Glass (Windows, Skylights, and Glass Within Doors).................................................................................................. 25 Exterior Doors.................................................................................................................................................................................................................... 26 Bay Windows ..................................................................................................................................................................................................................... 27 Takeaways................................................................................................................................................................................................................................... 28 References .................................................................................................................................................................................................................................. 29

Insurance Institute for Business & Home Safety 3
Executive Summary
In a wildfire, buildings ignite through a complex ignition mechanism linked to embers and flames. Due to the variety of possible ignition scenarios, a single hardening strategy is not effective at reducing the chance homes will ignite. To meaningfully reduce the risk, a two-tiered approach that applies the current state of the science is necessary and must include:

1. foundational, systemic protection of a home against embers

2. an additional layer of mitigations to guard against flame exposure Wildland Fire Embers and Flames: Home Mitigations That Matter discusses available literature on the vulnerability of each component of the home and the need for this systematic, all-inclusive application of these mitigations.

Mitigations Against Embers and Flames

Roofs As a large, elevated surface with complex geometry and a range of slopes, roofs are prone to ember accumulation and eventual ignition if the roof is not fire resistant. A Class A roof covering reduces this vulnerability.

Gutters In gutters, leaves and pine needles accumulate, providing embers with a susceptible fuel bed. Gutters should be kept clean with a noncombustible cover to limit debris accumulation. Noncombustible gutters also shield the fascia board from flame exposure.

Vents Vents are exposed to flames and embers. Protect the vent from flames by choosing vents made of a noncombustible material. Vent openings must be protected with a 1/8 -inch or finer noncombustible mesh screen to prevent large embers from entering the house and igniting the house from the inside. Similarly, dryer vents should have a noncombustible louver or flap.

Zone 0 Winds carry debris and embers during wildfires, which settle near homes as the wind interacts with the structure. Combustibles should be kept at least 5 feet from the home to minimize the risk of short flames to the home and provide no fuel for embers to land on. A well -maintained Zone 0 with no combustibles also ac ts as a fuel break to stop surface fires approaching the home and reduce the likelihood of home ignition.

Fences Combustible fences provide a path of fuel for fire to reach a home. Even for homes with noncombustible cladding, flames from a burning fence can threaten eaves and nearby windows. Installing a noncombustible fence inside Zone 0 breaks the path of fire to a home.

The combination of trapped debris between back -to-back fences and the fence itself creates an extremely susceptible fuel bed for embers. This fence design should be avoided in the WUI.

Decks Deck assemblies (walking surfaces, joists, and posts) are vulnerable to embers and flames. Embers can fall between deck boards and ignite the joists beneath or combustibles in the underdeck area. The odds of underdeck flame impingement are minimized if the underdeck area is well -maintained with no combustible materials.

Where decks are low to the ground, enclosing the underdeck area with 1/8 -inch or finer

Insurance Institute for Business & Home Safety 4
noncombustible mesh reduces the likelihood of debris and ember accumulation. A solid walking surface limits the ignition potential of the deck joists as no e mbers can reach them; this means the joists are unlikely to become a pathway for fire to reach the home.

To best reduce the odds of deck ignition, choose a noncombustible deck assembly (including joists, railings, posts, and walking surface).

Accessory
Buildings
When spot fires ignite accessory buildings like sheds and gazebos, short local flames transform into tall flames that radiate significant amounts of heat and/or touch nearby buildings. To limit these kinds of exposures, all accessory buildings wit hin 30 ft of the home should be built with the same mitigation measures as the home.

Eaves The geometry of eaves traps heat from flames and hot gases. While field evidence of ignitions is anecdotal, protecting eaves with noncombustible soffits mitigates the ignition potential.

Walls When flying embers hit a wall, the embers lose their kinetic energy, fall to the ground, and accumulate. A 6-inch vertical noncombustible clearance at the base of exterior walls limits the exposure to siding from embers.

While a 6-inch vertical clearance protects a wall from embers, more action is needed to provide protection from flames. Their geometry makes walls suitable recipients of radiation and flame contact in WUI fires. The spread of flame through walls can be slow, but surface flame spread on combustible siding occurs quickly. This exposes windows and eaves to direct flame contact and can begin the cascade of damage for a home.

Noncombustible cladding eliminates the chance of such flame exposures.

Windows Windows are vulnerable to flame contact and radiation. Multipaned windows are more resilient by providing multiple layers of protection before flames can penetrate the home. Tempered glass further increases resilience because of its higher resistance to flame radiation.

Doors Flames are less likely to reach exterior doors with proper defensible space around the home. However, wind -blown embers may still accumulate at the base of a door or penetrate small openings around the door and ignite the door jamb. Therefore, t he entire door assembly should be mitigated. Fire -rated doors are the most practical solution due to the lack of noncombustible door assemblies (door jamb) on the market.

Bay
Windows
The geometry of bay windows traps heat underneath them. While field evidence of ignitions is anecdotal, enclosing this area with noncombustible materials eliminates the risk.

Insurance Institute for Business & Home Safety 5
Wildfire Mitigation Issues in Brief
The socioeconomic impact of wildfires on communities has long -lasting consequences when homes are damaged or destroyed. In addition to immediate costs such as fire suppression and rebuilding, local and national businesses are also affected by interruptions in labor, supply chain, demand for goods and services (Dale, 2010), and even virtual needs such as video streaming platforms. To protect communities from these broad impacts, every home within the community must take specific actions to mitigate the risk of wildfire.

Wildfire loss estimates are influenced by drought and climate trends, population growth in high -hazard areas, and construction culture in wildfire -prone areas (Aon Benfield 2016; Kramer et al., 2019 ). From 1980 to 2021, about 70% of losses due to wildfires in the United States happened in California (Smith, 2020). The rapid development of land in California has outpaced the enhancement of scientific measures to estimate the wildfire risk, evaluate building materials, and provide policy makers with methodical long -term views (Moore, 1981). The California Department of Forestry and Fire Protection (CAL FIRE) took steps to respond to this need in 1982 by introducing the Fire Hazard Severity Zone maps. These maps were then updated in 2007 with three levels of increasing fire hazard severity across California, namely medium, high, and very high. Structures built in the State Responsibility Area (SRA) and high and very high fire hazard severity zones in the Local Responsibility Areas (LRAs) must meet specific building materials, systems, and assembly requirements. The California Building Code Chapter 7A ( denoted as Chapter 7A in this document) outlines these minimum requirements (California State Fire Marshal, 2022).

Buildings constructed with fire -resistant materials, such as those built in compliance wi th the 2007 or newer edition of Chapter 7A, can be less vulnerable to wildfires (Miller et al., 2022). After analyzing survived structures from wildfi res in Southern California, Syphard et. al (2017) concludes that buildings with vinyl window frames, stucco exterior construction, dual-paned windows, and tile roofs had a higher survival rate.

Recently built structures were more likely to use these materials. However, Knapp et al. (2021) did not find the effects of Chapter 7A–compliant buildings to be statistically significant to the survival rate. This finding could be a result of the requirements of Chapter 7A, which are limited to building materials, systems, and assemblies, while the hazards that local fuel around a building can create is not considered. The hazard intensity from local fuels can vastly vary, which directly influences the performance of different building materials (Caton et al., 2017 ). To address this issue, California’s Board of Forestry and Fire Protection is currently amending the requirements for maintain ing a defensible space, 0 –30 ft and 30 –100 ft, near buildings (Board of Forestry and Fire Protection, 2018). Acknowledging the threat of embers, the Board of Forestry and Fire Protection assembled a group of subject matter experts and stakeholders to update the regulations and include requirements for 0 –5 ft (called Zone 0), which is under development . The lack of clarity in Chapter 7A regarding the building features a nd associated regulations is apparent (Intini et al., 2020); one of which is the requirements for defensible space, specifically 0–5 ft from the building. This will be discussed in detail subsequently. In addition, Chapter 7A provides several prescriptive and performance-based options for compliance of each built environment component addressed in the code.

A user could assume that these options provide comparable fire protection, but since a range of ignition - resistant material options can comply, these options do not provide comparable fire protection. Also, as previously mentioned, the enforcement of Chapter 7A is limited to new construction in the SRA and the very high fire hazard severity zones in the LRAs. These provisions are currently not applicable to existing structures unless the local jurisdiction has included such a provision through a locally adopted ordinance.

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In response to the need to quantify the performance of different components and provide clear guidance to maintain a defensible space, IBHS published the S uburban Wildfire Adaptation Roadmaps (Insurance Institute for Business & Home Safety, 2021 ). Fuel management, decks, fences, building shapes, exterior walls, roofs, vents, and eaves are addressed in this report. Individually and collectively, resilie nt choices in these eight areas reduce the likelihood of ignition that result in catastrophic building loss in a community threatened by wildfire. While there are some actions that are obvious and follow conventional wisdom, other actions are less obvious and require an expert opinion until research can provide more insight. While Chapter 7A provides a range of prescriptive and performance -based options, the Suburban Wildfire Adaptation Roadmaps discriminate the fire performance of individual building compo nents based on their characteristics and fill the gap on defensible space guidance.

Mitigating Wildland-Urban Interface (WUI) fire hazards is often viewed as either a voluntary “every little bit helps” or a “one-size-fits-all” effort (Maranghides et al., 2022a). Yet both approaches leave significant gaps and create a false sense of risk reduction (Maranghides et al., 2022a; Penman et al., 2015). Research shows if a house meets the group of recommendations in the Suburban Wildfire Adaptation Roadmaps, there will be a reduced possibility of ignition compared to a house that does not (Cohen, 2000; Maranghides et al., 2021a). The impact of these recommendations would be greater if all buildings in a neighborhood took these measures.

Mechanisms of Ignition
Buildings are ignited by embers and flames during wildfires. Flying embers and wind -blown, ground - traveling burning debris are by far the m ost prevalent attack mechanisms threatening structures during a wildfire. CAL FIRE identified embers as the major cause of home loss (Mell et al., 2010). Potter and Leonard (2011) reported that “well over 90% of houses were ignited in the absence of direct flame attack or radiant heat (exceeding 12 kW/m2) from the main fire front.” Hence, embers cause a great deal of damage, whether directly or indirectly.

Direct ignition by embers happens wh en embers land and accumulate on combustible components of the building and ignite these components or when embers enter the building through openings and ignite interior materials. Small-scale (Richter et al., 2022) and full-scale experimental studies (Cohen, 2000; Davis, 1990; Hedayati et al., 2022; Suzuki et al., 2017) demonstrate that accumulated embers are capable of directly igniting common combustible building components. Embers can also penetrate through openings and ignite the combustibles, such as furniture, inside a building (Quarles et al., 2010; Robertson, 2013).

Indirect ignition by embers occurs when embers accumulate on combustibles near a building and ignite these materials. The resulting flames ignite a component of the building by radiant heat and/or direct flame contact. These spot fires typically have notably lower intensity relative to the main fire front (Potter & Leonard, 2011 ), but under favorable conditions , these spot fires can spread to nearby structures. It is important to note that only tall, thick flames can radiate suffic ient heat to ignite buildings, while smaller flames need to be close or in contact with the building to cause ignition (Himoto, 2022).

After wildfires, unburned tree canopies are commonly found in close proximity to areas destroyed by a crown fire. These unburned areas are commonly referred to as “islands .” This pattern contrasts with the

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damage pattern often seen in floods where areas within the flood zone are contiguously destroyed. Fire spreads when the conditions for combustion —the fire triangle —are met along its path. Combustion requirements in the fo rest apply equally to WUI fires where structural and wildland fuels are present (Cohen, 2000). Reducing the vuln erability of buildings to embers and flames would result in “islands” of homes and buildings in the WUI within the path of a wildfire.

Although experimental and numerical studies providing information about ember storms in the WUI exist, predicting the path and accumulation position of embers is challenging. During flight, embers follow an unpredictable flight path influenced by building features and environmental parameters. The geometric characteristics of buildings, density of buildings in a community, and characteristics of receptive fuel beds affect ember accumulation, as does the shape of the embers, fuel from which the embers were generated, and local wind patterns, particularly wind vortices (Caton et al., 2017; Hedayati et al., 2019; Nguyen & Kaye, 2021).

Buildings can be affected by multiple sources of ignition during a wildfire, including radiative heat transfer from flames, convective heating from wind-blown plumes, continuous or intermittent flame contact, and localized heating from spot fires near the building (Himoto, 2022). This complex thermal exposure requires systematic fuel management and home hardening strategies to bend down the risk curve. In the WUI, ember-caused spot fires can use vulnerable homes as fuel to grow beyond a local threat into tall flames and lead to extreme fire behavior threatening neighboring homes. While it may be possible to identify the likely ignition pathway in an ember storm for an isolated house, chaotic ember accumulation patterns in communities make it nearly impossible to identify a single vulnerable component for a home in a community. Accepting these complexities of ember -caused ignitions, hardening t he home and its immediate surroundings against all known ember vulnerabilities requires a systematic, all -inclusive hardening approach in the entire community. If all components of a home in a community are hardened against embers, the odds of a house becoming engulfed in tall, thick flames and radiating substantial heat to its surroundings are reduced. This allows the first responders to address spot fires early and prevent the spot fire from growing into a suburban conflagration.

Mitigations That Matter
A home is a system of components. To mitigate the risk of wildfire, all components vulnerable to embers and flames must be mitigated systematically. The available literature about the vulnerability of each component is discussed subsequently.

Roof
Wind patterns near buildings heavily influence ember distribution patterns and accumulation locations.

Because roofs are a large, elevated surface with complex geometry and a range of slopes, they are prone to ember accumulation during ember storms. The re gions on the rooftop where embers reach stability and rest are also a complex function of roof geometry, particularly roof valleys. Roof valleys are often covered with organic debris, which is particularly susceptible to ignition from embers (Nguyen & Kaye, 2021).

The vulnerability of roofs to ember storms is well studied. Several retrospective studies have reported a statistical correlation between wood roofing and building losses due to ember exposure (Davis, 1990; Foote

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et al., 2011 ). Moore (1981) reported that out of 1,850 homes, 50% of homes with wood roofs within 30 ft of burning vegetation ignited while only 24% of homes with fire-resistant roofs ignited in the 1961 Bel Air Fire in Southern California. Foote (1994) found the degree of flammability of the roof had a significant impact on home survival where h omes with nonflammable roofs had a 70 % survival rate compared to 19% for homes with flammable 1 roofs. After the 1991 Oakland Hills Fire in California, it was estimated that each burning home with a non-fire-retardant-treated wood shake roof contributed to the ignition of ten other homes (Bryner, 2000).

Standard test methods such as ASTM E108 (American Society for Testing and Materials, 2020) and UL 790 (Underwriters Laboratories, 2022 ) evaluate the fire performance of different roofing materials. In 2020, IBHS released a report on the vulnerability of different roofing materials and roof geometry and updated the report in 2021 (Insurance Institute for Business & Home Safety, 2021).

Roof: As a large, elevated surface with complex geometry and a range of slopes, roofs are prone to ember accumulation and eventually ignition if the roof is not fire resistant. A Class A roof covering reduces this vulnerability.

Gutters and Downspouts
Gutters are a prime location for leaves and pine needles to accumulate, which can expose the edge of the roof to direct flames during wildfires (Sindelar, 2011). Figure 1a shows a defended home in the Camp Fire (2018) in Butte County, California, where the evidence suggests that embers ignited debris in the gutter and caused damage to the roof deck. Likely due to intervention from first responders, the damage was contained to the gutter and roof edge and did not spread to the rest of the home. IBHS’s research highlighted a similar vulnerability for gutters, as can be seen in Figure 1b. Note that the time it takes for the vinyl gutter to melt and fall might exceed the required time to ignite the roof deck.

1 There is no clear definition of flammability in this study. It’s likely limited to non-fire-retardant-treated wood shakes.

Figure 1. Direct flame contact to the edge of the roof caused by ignited debris in the gutters during ember storms (a) in the Camp Fire (2018) in County, California (home defended by first responders), and (b) a vinyl gutter melts off a house during testing at the IBHS Research Center.
a
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Frequent clearing of gutters of all debris would reduce this vulnerability. A noncombustible gutter is an excellent choice when the fascia board is not covered with a metal drip edge . Recent testing by IBHS shows noncombustible gutters provide protection for fascia boards or rafter tails, dependin g on the construction type, against flames. Figure 2 shows photographs taken during experiments at the IBHS Research Center evaluating building -to-building fire spread. In this test, half of the fascia board was covered with a metal gutter and half of it w as not covered. The uncovered portion ignited, which caused some damage to the building’s roof deck. Figure 2b compares the covered and uncovered parts of the fascia board after the test. In another test, a vinyl gutter was exposed to a flame source 20 ft away. The vinyl gutter melted and exposed the fascia board to flame contact about 10 minutes after ignition, shown in Figure 2c.

Figure 2. A noncombustible gutter can provide protection for the fascia board if a metal drip edge is not installed. (a) shows fascia board ignition during the experiment and (b) shows the fascia board condition after the test. In (c), a vinyl gutter deformed due to radiant heat/intermittent flame contact and fell off. a
b
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Gutters and Downspout s: In gutters, leaves and pine needles accumulate, providing embers with a susceptible fuel bed. Gutte rs should be kept clean with a noncombustible cover to limit debris accumulation. Noncombustible gutters also shield the fascia board from flame exposure.

Vents
Unless a home has been built with an unvented design, unconditioned areas (e.g., attic and crawl spaces) must be ventilated to avoid elevated moisture and temperature conditions . Since 2016, Chapter 7A has required new vents to be resistant to embers and flames as tested by ASTM E2886 (American Society for Testing and Materials, 2014); this requirement will be added to the International Wildland-Urban Interface Code in 2024. Recent full-scale tests at IBHS show that ASTM E2886 –compliant vents do not allow large embers to pass through. The embers c ollected behind these vents were small and incapable of igniting combustibles in the attic, as seen in Figure 3a.

However, older and inadequately protected vents can provide a pathway for fire and specifically for wind- blown embers to enter the building (Caton et al., 2017 ; Manzello et al., 2007 ; Quarles, 2017 ; Quarles & Gorham, 2019). Installing vents with metal mesh screens is an accepted mitigation strategy to prevent large embers, depending on the mesh size, from entering bu ildings (Hakes et al., 2017 ). Sharifian Barforoush and Du Preez (2022) identified eight different mechanisms when embers interacted with mesh screens: passing, stopping, splitting, shattering, pausing, bouncing, slipping, and wandering. Sharifian Barforoush and Du Preez report that, except for some long needle -shaped embers, the 1/16 -in. mesh screen was highly effective against both large and small embers; Figure 3b demonstrates how embers could pass through unprotected vents in their experiment.

The mesh screen protecting a vent opening should be large enough to allow proper ventilation for the building, but small enough to keep larger embers from entering. The surface area of embers depends on several factors, including wind speed and type of fuel from which the ember originated. During a Joint Fire Science Program–funded research project between University of North Carolina at Charlotte, University of Maryland, IBHS, and other collaborators, the ember (firebrand) production from different structural and vegetative fuels was investigated (Bahrani et al., 2020; Hedayati et al., 2019; Hedayati et al., 2020). The results showed that the mass and size of embers fol lowed a right -skewed distribution. The histogram and cumulative density function for pine tree embers are shown in Figure 3c. Common mesh screen sizes for commercially available vents are 1/4 -in. and 1/8-in. The opening size of a 1/ 8-in. mesh screen is about 0.06 sq in. This point is highlighted on the graph in Figure 3c, which shows that about 38% of the embers were smaller than 0.06 sq in. Manzello et al. (2011) also reported that smaller mesh size reduced the ember penetration ratio, defined as the number of embers leaving from the mesh and the number of embers arriving at the mesh for a given time interval.

When considering defensive measures, it becomes apparent why vents need to be protected. Firefighters can suppress small flames and burning components when they see the fire, but when embers enter through vents, the house is ignited from the inside. When the fire begins inside the house, first responders

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have little chance of suppressing the fire because the fire can become large before it is visible from the exterior.

Vents: Vents, including dryer vents, are exposed to flames and embers. Protect the vent from flames by choosing vents made of a noncombustible material. Vent openings must be protected with a 1/8 -in. or finer noncombustible mesh screen to prevent large embers from entering the house and igniting it from the inside. Similarly, dryer vents should have a noncombustible louver or flap.

Vertical Ground Clearance
Wind-blown objects, embers, and debris tend to accumulate at the base of a wall following a change in the wind flow (Manzello et al., 2011). These wind-blown debris are often lower-density fine fuels that can be Figure 3. (a) Embers get stuck on the outside of an ASTM E2886–compliant vent until they become small enough to penetrate through during building separation tests at IBHS and (b) embers passing through the vents when no mesh is used (Sharifian Barforoush & Du Preez, 2022); image used with permission. (c) Size distribution of embers from pine trees. a
b
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easily ignited and expose the building cladding to short flames (Manzello et al., 2012b). The importance of ground clearance to reduce ignition potential of a home has been reported in post -event investigations (Quarles et al., 2013).

Full-scale experiments at IBHS (Quarles et al., 2023 ) and the Fire Research Wind Tunnel Facility in Japan demonstrated that accumulation of embers at the base of an exterior wall can ignite cladding wall is in contact with embers and debris (Manzello et al., 2011 ; Manzello et al., 2012a ; Nazare et al., 2021 ; Suzuki & Manzello, 2017). Manzello et al. (2017) exposed corner assemblies to embers with different types of mulch at the base with 102 mm (4 in.) and 203 mm (8 in.) vertical noncombustible clearance. At a 203 mm vertical clearance, the Japanese cypress mulch and pine bark nugget mulch ignited the corner assemblies, but the shredded hardwood mulch did not ignite the corner assembly. At a 102 mm vertical clearance, the Japanese cypress mulch ignited the corner assembly.

This vulnerability has been observed by the authors of this paper in previously unpublished ember exposure tests at the IBHS Research Center. During these tests, the base of the wall segments with wood siding ignited numerous times. From these observations, the authors tested different vertical separation Figure 4. Ember accumulation at the base of the wall causing ignition (a and b) at the IBHS Research Center, (c) in the post-Camp Fire (2018) investigation in Butte County, California, and (d) at the base of a wall in the Glass Fire (2020) in Napa and Sonoma Counties, California, which did not have the opportunity to grow because of a noncombustible vertical clearance. a
b
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distances between the ground and the base of the combustible cladding to mitigate this, shown in Figure 4b. Direct ignition of the wall occurred only during the no-clearance tests.

Debris piling up against the base of walls during wildfire events can create a susceptible fuel for embers to land on. Depending on the amount of debris, the size and intensity of these small flames can vary.

Because a 6-in. vertical clearance was already required for combustible wood siding by the International Residential Code since 2000 for moisture degradation issues, IBHS began recommending a 6 -in. vertical clearance to mitigate this ember vulnerability in 2013 (International Code Council, 2000 ). In Australia, a more conservative 400 mm —or 15 in. —clearance is recommended where a wall meets any horizontal projection including the ground, decks, or roof sections (Queensland Government & Commonwealth Scientific and Industrial Research Organization, 2020 ). A dditional future research is needed to better understand debris accumulation.

Vertical Ground Clearance: Elevated winds during wildfires cause burning debris to roll and become trapped against walls. When flying embers hit a wall, the embers lose their kinetic energy, fall to the ground, and accumulate at the base of the wall or very close to it. A vertical noncombustible clearance of at least 6 in. at the base of exterior walls limits the exposure to siding from these hot, burning objects.

Fuel Management in Zone 0
The importance of fuel treatment and management near buildings (e.g., creating and maintaining an effective “defensible space”) to minimize the likelihood of flame contact and extended radiant heat exposure to reduce the risk from wildfire has been studied experimentally (Cohen, 2000, 2004), in post- event investigations (Insurance Institute for Business & Home Safety, 2020; Maranghides et al., 2022a), and by scholars active in the public policy arena (Miller et al., 2022). Historically, there have been two defensible space zones: generally described as 0–30 ft and 30 –100 ft or to the property lin e; however, the two zones vary in size in different guidelines (Board of Forestry and Fire Protection, 2018 ; Dennis, 2003 ; Federal Emergency Management Agency, 202 0). According to Moo re (1981), prior to the 1970s, the insurance industry used four levels of “brush clearance,” namely 0 –30 ft, 30 –60 ft, 60 –100 ft, and 100+ ft for hazard mapping purposes, which is a similar concept to defensible space. The University of Nevada, Reno’s Living with Fire program has advocated for a near-home noncombustible zone since 1991 (Smith & Adams, 1991).

Since 2011, IBHS has advocated for dividing the 0 –30 ft zone into two separate zones (0 –5 ft and 5 –30 ft) because of the importance of ember accumulations and ignitions of combustible materials near the building, which create a critical threat to the building from potential small flames. During an ember storm created at the IBHS Research Center, as shown in Figure 4a, the accumulation of embers within the first 5 ft of the building is clear (Quarles et al., 2023). Embers accumulate at the base of the wall and within the first 5 ft from the building. Accumulation of embers in the vicinity of obstacles is also reported by Suzuki and Manzello (2017).

Any combustibles in the 0 –5 ft zone are exposed to ember accumulation and potential ignition. Clearing this area of all combustible materials—vegetative and nonvegetative—plays an important role in reducing the likelihood of home ignition. Quarles and Smith (2011) studied the fire behavior of eight different kinds of mulch, namely: composted wood chips, medium pine bark nuggets, pine needles, shredded western red cedar, Tahoe chips, Tahoe chips with fire retardant, single layer Tahoe chips, and shredded rubber. They reported that, “with the exception of the composted wood chips, all of the mulch treatments

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demonstrated active flaming combustion” and that “shredded rubber, pine needles and shredded western red cedar demonstrated the most hazard ous fire behavior” (Quarles & Smith, 2011 ). The fire behavior of surface fuels like mulch markedly change with wind and slope (Sánchez-Monroy et al., 2019 ).

Hedayati et. al (2018) exposed the cladding of a full -scale building to an 80 kW gas burner for 15 min and monitored the temperature on the wall when the test building was oriented at different angles to the wind. Hedayati et al. report that when the flame was more than 5 ft away from the building, the ignition potential was significantly lower than at closer distances.

Investigations after wildfire events revealed increased vulnerability to the home from nearby combustibles.

The investigation performed after the Grass Valley Fire (2008) in San Bernardino County, California, by Cohen and Stratton reported that in most cases, the destruction was not because of high-intensity flames, which are typically thick with large surface area. Instead, Cohen and Stratton found embers ignited the buildings directly or ignited a spot fire near the building where surface fuel touched wood siding (Cohen & Stratton, 2008). In Butte County, California, the National Institute of Standards and Technology’s (NIST) post-Camp Fire (2018) report also provided examples where overhanging trees within the 0–5 ft zone could ignite the building (Maranghides et al., 2021a). As shown in Figure 5d from NIST’s post-Camp Fire report, a fence was about 6 ft away from the building and branches from a tree extending towards the house appear longer than 1 ft. In other words, the branches were in the 0–5 ft zone and contributed to a pathway for fire. This vulnerability has also been highlighted in the IBHS post-Glass Fire (2020) investigation in Napa and Sonoma Counties, California. In this case, vegetation was observed to provide a pathway for ignition when plants—even in small amounts—touch the building as shown in Figure 5b. The h ouse in Figure 5b was likely defended by first responders during the event.

At this time, little research has been done to understand the flammability of specific plant species and how they create a vulnerability for a home. Without a species -specific und erstanding of the vulnerability, current field observations and laboratory experiments support no vegetation in Zone 0 until additional research has been conducted.

Vegetation in Zone 0
Vegetative fuel—including dead, organic mulch—can generate a fire pathway when touching a building.

As previously mentioned, t he accumulation of embers near buildings can ignite these fuels (Manzello et al., 2006; Suzuki et al., 2015). In either scenario, the vegetative fuel can allow flames to reach the building's cladding. As shown in Figures 5a and b, investigations following the Glass Fire (2020) in Napa and Sonoma Counties, California, highlighted this pathway where embers landed in the front yard and ignited the wood mulch. The mulch carried the fire all the way to the home, ignited the hot tub, and damaged the building.

Note the landscape barrier, which separates wood mulch with mineral soil. There is no visible damage to the building where the wood mulch is not present against the home. This can also be observed at another home in Figure 5c where the fire stops as the soil covering changes from wood mulch to gravel.

When evaluating available vegetation within the first 30 ft of homes affected by the Witch Creek Fire (2007) in San Diego County, California , it was found that 67% of homes with unmaintained vegetation were destroyed, while only 32% of homes with maintained defensible space were destroyed (Maranghides et al., 2013). Analyzing over 2,000 structures in San Diego County, Syphard et al. (2014) concluded that structures were more likely to survive a fire with an effective defensible space “immediately adjacent” to them.

Syphard et al. also report ed that reducing woody vegetation cover up to 40% immediately adjacent to

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structures and preventing vegetation from overhanging or touching structures were the most effective actions.

Using Principal Components Analysis (PCA) and Generalized Additive Mixed Models on data from 27 independent forest fires in New South Wales, Australia , Penman et al. (2018) concluded that vegetation touching houses likely caused ignition of the house once that vegetation ignited. It is difficult to distinguish between vegetation touching houses, garden cover, and overhanging vegetation in this study, which was a
Figure 5a-b. Example of vegetation in small amounts located in Zone 0 creating a pathway for fire spread: (a) Wood mulch provided a pathway for fire to get close to the building and ignite a hot tub during the Glass Fire (2020) in Napa and Sonoma Counties, California; (b) Ground-level plants during the Glass Fire (2020). b

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an uncertainty source in their PCA analysis. While Gibbons et al. (2012) reported similar results, Wilson and Ferguson reported that vegetation very cl ose to the siding and touching the roof did not increase the destruction rate of buildings (Wilson & Ferguson, 1 986). As a caveat, Wilson and Ferguson focused on vegetation in contact with the roof rather than any other components.

Analyzing pre- and post -fire aerial imagery and connecting the results to the insurance claims d ata, ZestyAI concluded that if the first 0 –5 ft around buildings were maintained to a light vegetation density, the likelihood of destruction was about 2 times lower compared to buildings with high density vegetation in the first 0–5 ft (Arrowsmith et al., 2021). The report goes on to say, “having heavy vegetation, more than 50% coverage, (including brush, trees, and shrubs) immediately around the home can nearly double the chance of destruction.”
Given the challenging nature of predicting wildfire occurrence and growth, homeowners often have little to no time to prepare for an approaching wildfire. Therefore, consistent maintenance of Zone 0 is required when a wildfire is not threatening.

Vegetation in Zone 0: Wind carries debris and embers during wildfires, which settle near homes as the wind slows down and interacts with the structure. Combustibles should be kept at least 5 feet from homes to minimize the risk of short flames to the homes and to provide no fue l for embers to land on. A well - maintained Zone 0 with no combustibles also acts as a fuel break to stop surface fires approaching the home and reduces the likelihood of home ignition.

Fences in Zone 0
Structural fuels, fences, and decks in contact with or within 5 ft of the main building can also provide a pathway for fire to spread. Laboratory tests and post -event investigations (Butler et al., 2022 ; Insurance Institute for Business & Home Safety, 2020) show the vulnerability of combustible fences, as seen in Figure 6a-d.

Figure 5c-d. Example of vegetation in small amounts located in Zone 0 creating a pathway for fire spread: (c) Tree branches overhanging Zone 0 burn during the Camp Fire (2018) in Butte County, California, and provide a pathway for fire to reach a home (Maranghides et al., 2021a), used with permission; (d) Low-intensity surface fire (ember caused) stopped as it met gravel during the Glass Fire (2020), view from the deck to the backyard. d
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Fences in Zone 0: Combustible fences provide a path of fuel for fire to reach a home. Even for homes with noncombustible cladding, flames from a burning fence can threaten vulnerable components such as eaves and nearby windows. Installing a noncombustible fence inside Zone 0 breaks the path of fire to a home.

Attached Decks
Attached decks are another structural fuel that can exist in Zone 0. Dossi et al. (2022) recently introduced a Wildfire Resistance Index for buildings in California and Portugal. For buildings in California, Dossi et al. reported that building features, such as vent screens and decking material , are highly correlated to the damage level of the building, and protecting these features increases the survival likelihood of the building.

Once ignited, decks can expose a building’s cladding (siding), exterior wall components such as windows and doors, and the under -eave area to flames and radiant heat , as shown in Figure 7 . In a wildfire, decks are typically exposed to embers on their top surface and flame impingement on the underside (Hasburgh et al., 2017; Leonard, 2019; Manzello & Suzuki, 2019 ; Meerpoel-Pietri et al., 2021 ). Given that the majority of homes in a wildfire ignite due to embers, if the underdeck area is clear of combustible materials, the risk of flame impingement to the underside of the deck is reduced, except for decks built on a slope. Keeping the underdeck area clear of combustible materials is especially important for low elevation decks where Figure 6. Examples of combustible fencing providing a pathway for fire to the house, damaging the noncombustible siding and eave (a and b) in the Glass Fire (2020) in Napa and Sonoma Counties, California, defended; (c) in the Camp Fire (2018) in Butte County, California, defended by first responders (Insurance Institute for Business & Home Safety, 2020); and (d) at the IBHS Research Center where the arrows indicate the direction of fire spread. d
c
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the maintenance of the underdeck area is troublesome, and in the case of ignition, flames can reach the joists and ignite them. Without an underdeck flame impingement, the only threat to the d eck is from embers accumulating on the deck surface, where embers typically accumulate in the between -board gaps on the joist or at the corners where the deck assembly meets the siding (Manzello & Suzuki, 2014 , 2019; Quarles & Standohar-Alfano, 2018).

Hedayati et al. (2022) reported that the substructure of the decks plays a major role in its vulnerability to flame impingement from below. Once the joists ignite due to the initial flame impingement exposure, the joists can burn for an extended period and continuously expose the bottom side of the deck boards to flames. Hedayati et al. reported that boards above a joist did not burn intensely if the joist wasn’t engulfed in flames.

Attached Decks: Deck assemblies (walking surfaces, joists, and posts) are vulnerable to embers and flames. Embers can fall between deck boards and ignite the joists beneath or combustibles in the underdeck area. The odds of underdeck flame impingement are minimized if the underdeck area is well- maintained with no combustible materials. Where decks are low to the ground, enclosing the underdeck area with 1/8-in. or finer noncombustible mesh reduces the likelihood of debris and ember accumulation.

A solid walking surface limits the ignition potential of the deck joists as no embers can reach them; this means the joists are unlikely to become a pathway for fire to reach the home (Hedayati et al., 2022 ). To best reduce the odds of deck ignition, choose a noncombustible deck assembly (including joists, railings, posts, and walking surface).

Fuel Management Beyond Zone 0
While Zone 0 is designed to minimize the threat of localized fires from embers and creeping fires (Ascoli et al., 2018), the area beyond Zone 0 also plays a role in protecting the structure in a wildfire . A structure with fire-resistant or noncombustible materials is more likely to withstand a creeping fire than a fire with tall flames (Maranghides et al., 2022a ; Syphard & Keeley, 2019 ). Moreover, suppression efforts by first responders are more effective if they can enter the parcel without risking their safety (Penman et al., 2015).

With effective structural and vegetative fuel management beyond Zone 0, the threat of tall, thick, high - intensity flames frequently resulting from flying embers is reduced.

Vegetation Beyond Zone 0
Reducing the threat of tall, thick, high-intensity flames can typically be achieved by creating discontinuity between trees and bushes in both the horizontal and vertical directions. Statistical analysis of post -event investigations reveals that vegetative fuels located near buildings add to the vulnerability of the structure.

The Ramsay et al. (1987) post-Ash Wednesday Bushfire analysis reported that the amount and type of vegetation near houses was an important factor in their damage state. Houses were more likely to have survived when they did not have dense vegetation around them. Cohen and Butler (1996) modeled radiative heat transfer from burning vegetation and concluded that veg etation thinning within 40 m (131 ft) of a building mitigates ignition. Analyzing post -fire data collected in Southern California, Miner (2014) concluded that reducing vegetation density by 25% is sufficient to reduce the risk. Miner also mentioned that in the short term, the most important action is to remove flammable vegetation adjacent to or overhanging homes. Gibbons et al. (2018)analyzed about 500 homes affected by Southern Australia bush fires and reported that removing vegetation close to homes is “at the forefront of mitigations.” The study

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concluded that removal of shrubs and trees upwind of the house reduces the risk of house loss more effectively than removing trees very close to the house. Samora -Arvela et al. (2023) analyzed pos t-fire investigation data in Portugal and reported that the presence of trees and bushes within a radius of 30 m (98 ft) from the buildings was the most important determining factor in the degree of damage or destruction of the buildings.

Post-fire investi gations show mixed findings on the vulnerability of trees near buildings. Numerous examples of destroyed buildings surrounded by green trees show that nearby trees do not always increase the vulnerability of a structure (Candian Broadcasting Corporation, 2018 ). Nonflammable vegetation between the fire and the home can be beneficial to protecting the home from embers and radiant heat (Foote et al., 1991 ). Conversely, Manzello and Suzuki (2021) show that a noble fir tree can intensely ignite under ember exposure, demonstrating the species-to-species variability in risk.

Vegetation Beyond Zone 0: It is clear that more methodical research is needed to investigate home vulnerabilities to nearby burning vegetation considering vegetation type and density, horizontal and vertical connectivity, and relative location t o the home under windy and sloping conditions. Additional research would define terms such as “low flammability vegetation”(Anderson, 1970), “irrigated vegetation” (Valachovic et al., 2021 ), and “sparse out vegetation” (Valachovic et al., 2021 ) used in ex isting literature.

While the vast majority of post -event investigations advocate for the removal of dense vegetation on a parcel, studies like Foote et al. (1991) demonstrate uncertainty and the need for further research. Until additional research is available, the consensus among research groups and practitioners follows the conceptual spacing of vegetative fuels to reduce fire spread. Trees and shrubs beyond Zone 0 should be spaced following a crown-to-crown distance and vertical clearance of 10 ft (Colorado State Forest Service, 2012) .

Accessory Structures and Outbuildings
Fire spread between buildings can cause widespread damage within a community (Cohen, 1995; Himoto, 2022; Maranghides et al., 2021b ; Rehm et al., 2002 ). The spread rate is influenced by slope, building size, distance between buildings, and wind direction and intensity (Cohen, 1995; Yuan et al., 2022). Because of the complexity of building -to-building fire spread, most efforts to understand t his phenomenon are limited to reduced -scale tests (Cicione et al., 2019 ; Narayanan et al., 2022 ) or numerical and stochas tic modeling (Cheng & Hadjisophocleous, 2009; Huang, 2020; Masoudvaziri et al., 2021). There have been a few experimental studies regarding fire spread between buildings; most of these studies have been based on radiation from flames jetting out through openings during an internal fire (Yuen et al., 2021).

During wildfires, on the other hand, the entire structure could be engulfed in flames, which leads to a drastically different fire behavior. Using some limited field observations, McG uire (1965) developed a theoretical model that calculates building separation based on the size of the buildings and the percent of openings on the building’s exterior. McGuire’s calculations are based on the ratio of the radiant heat intensity at the receiving surface to that at one or more radiating surfaces. His calculations suggest a 53-ft separation for a structure 10 -ft by 25-ft with 100% opening (almost the entire building in flames). Himoto et al. (2018) studied three arrays of mock buildings with dimensions of 3.6 -m by 3.6-m (11.8-ft by 11.8 -ft).

About 260 kg (573 lb) of wood cribs were loaded into the buildings. Buildings were separated by 0.5 m (1.6 ft) within the array, and the arrays were separated by 3.6 m (11.8 ft). Following the first fire, 15 out of 18 model houses were burned due to successive fire spreads that lasted about 50 min with a 1.6 m/s (3.5 mph)

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ambient wind. A study by Hasami (1997) examined the spread of fire from a heptane and propane burner to one three-story building (13.6-m by 9.1-m by 11.69-m, or 44.6-ft by 29.8-ft by 38.4-ft) and the spread of fire to two two-story buildings (roughly 4.5-m by 10-m by 7-m, or 14.7-ft by 33-ft by 22.9-ft). Approximately 3 m (9.8 ft) separated the burners from the main buildings, and 4.5 m (14.7 ft) separated the main building from the secondary buildings. The results of his tests are not available in English , but because of its relevance, the methodology is covered in this paper . Yuan et al. (2022) examined fire spread in wood buildings and observed that the fire spread from one wood building to three other wood buildings within 30 min of igniting the first. Configurations on b oth flat ground and an uphill slope show a reverse trend between building distance and thermal radiation.

Note that none of the experiments mentioned above incorporate the effects of wind on building -to- building fire spread. To fill this gap, IBHS committ ed to studying wind -driven building -to-building fire spread and the first phase of the project —fire spread from approximately 300 -sq-ft outbuildings —is currently under investigation. Fire spread from outbuildings to a main structure is a common fire spread mechanism in the WUI, as shown in Figure 8. Preliminary results indicated that a burning shed 30 ft away from the main structure would result in repairable damage to the main structure. Figure 9 shows two of these experiments. This research will be published in 2023.

Accessory Structures and Outbuildings: When accessory buildings ignite, usually due to spot fires spreading, short local flames transform in to tall flames that radiate significant amounts of heat and/or touch nearby buildings. To limit these kinds of exposures, all accessory buildings like sheds and gazebos within 30 ft of the home should be built with the same mitigation measures as the home.

Figure 8. Example of a shed damaging the main structure on a parcel in the Glass Fire (2020) in Napa and Sonoma Counties, California. In photo (a), a shed was about 6 ft away from the main structure (suppressed by first responders and the homeowner).

In photo (b), an attached outbuilding completely burned and damaged the main structure (suppressed by first responders). b
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Fences Outside of Zone 0
Real-world WUI fires have shown that fences located beyond Zone 0 contribute to fire spread in communities (Insurance Institute for Business & Home Safety, 2020; Maranghides et al., 2013; Maranghides & McNamara, 2016 ), as can be seen in Figure 10 . Australian researchers investigated the effectiveness of noncombustible and combustible fences in preventing bushfire spread. After ignition, the combustible fences ceased to act as barriers and contributed to the fire spread (Johnsson, 2018; Leonard et al., 2006).

In a recent study from NIST (Butler et al., 2022 ), the vulnerability of fences was examined. This research concluded that when combustible objects burn in close proximity, fire hazards are disproportionately higher. When a fire occurs, surface fuels—such as mulch and vegetative debris—burning close to the fence result in extreme fire behavior. In the NIST study, fires burned along mulch lining the base of a single fence row and parallel fences. An inferno consumed the fence pairs when positioned close together. The single fence row burned more quickly with mulch or debris present at the base than without mulch or debris.

Compared with fences where mulch or debris was not located at their base, individual fence rows burned Figure 9. Photographs of a wind-driven building-to-building fire spread experiment at the IBHS Research Center showing (a) a burning woodshed positioned 30 ft from the main building and (b) a burning metal shed positioned 10 ft from the main building. In both cases, the open shed door is facing the main building.

Figure 10. In the Glass Fire (2020) in Napa and Sonoma Counties, California, (a) a combustible fence provided a pathway for fire to spread uphill and damage both homes during fire, and (b) a wood fence spread fire and led to a cascade of damage (defended). b
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more slowly. According to the report, in a WUI environment, fences should not be built parallel to each other, even within 1 m (3 ft) of each other, as shown in Figure 11 . Along with providing fire a conduit, this design introduces severe flame and radiation hazards to the neighborhood.

Debris accumulated between back -to-back fences is rarely removed. Highly susceptible surface fuel trapped in a conduit-like channel is hazardous as it creates ladder fuel. When ignited, fire can rapidly grow and “carry the fire along toward your house in a matter of a few minutes, not hours” (National Institute of Standards and Technology, 2022).

Fences Outside of Zone 0: The combination of trapped debris between back -to-back fences and the fence itself creates an extremely susceptible fuel bed for embers. This construction method should be avoided in the WUI.

Eaves and Soffits
The under -eave area of b uildings—whether vent ed or unvented—is vulnerable to fire. Eaves are constructed in two basic ways: open eaves and enclosed or soffited eaves. In open eaves, the roof rafters that extend beyond the exterior wall are visible. Open eave construction is typical in the western Uni ted Figure 11. Fire behavior between parallel fences (a) 0.6 ft apart, (b) 1 ft apart, (c) 1.5 ft apart, (d) 2 ft apart, and (e) 3 ft apart and longer fence (Butler et al., 2022), used with permission.
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States. In enclosed or soffited eaves , the rafters are protected by a panel. The enclosing panel can be installed horizontally (extending from the roof edge back to the exterior wall) or parallel to the roof slope.

The overhang can protect walls from the rain and sun, but the overhang can also exacerbate wildfire exposure. The eave is susceptible to wind-blown embers and flames if nearby vegetation or combustible siding ignites. A 2008 FEMA guideline (Federal Emergency Management Agency, 2008) states that wider overhangs can be more vulnerable because wider overhangs trap more heat and embers. This is particularly true for buildings on sloping terrain with an open-eave design.

Experimental studies typically use open eaves as a “worst-case scenario,” which is usually used to create guidance (Manzello et al., 2012b ; Maranghides et al., 2022b ). Syphard & Keeley (2019) concluded from a statistical analysis of structure loss in California between 2013 and 2018 that enclosed eaves had a highly significant protective effect compared to no eaves and open eaves as seen in the relative r isk ratios. The existence of “temporary fuels” such as vehicles near the building also pose a direct flame contact and radiant heat threat to the eaves. Quarles et al. (2011) exposed soffited and open eaves to flame contact and radiant heat. Quarles et al. reported that open -eave designs that incorporate a fascia board are more vulnerable to direct flame contact exposures compared to soffited-eave designs. However, the open-eave design performed better against radiant heat exposure. It should be noted that most of the post -fire observations about eaves are anecdotal (Quarles et al., 2010 ) and more research on the vulnerability of eaves from surrounding fuels is needed.

Eaves and Soffits: The geometry of eaves traps heat from flames and hot gases. While field evidence of ignitions is anecdotal, protecting the eaves with noncombustible soffits mitigates the ignition potential.

Exterior Wall Covering/Cladding
Exterior walls are vulnerable to flames and radiant heat because of their geometry and area. Reentrant corners, an inside corner to the building, are particularly vulnerable. Ignition of siding can result in rapid fire growth (Green et al., 2022 ). When siding ignites, the heat can penetrate through the exterior surface to the underlying layers including sheathing and studs.

Investigating flame spread over combustible exterior wall s, the Institute for Research in Construction of the National Research Council of Canada concluded that some combustible claddings support “unlimited vertical flame spread” (Oleszkiewicz, 1990). Maranghides and Johnsson (2008) reported that flames jetting out of a window ignited a mock wall assembly 6 ft away —the minimum home separation distance required by some building codes —in 80 sec; these tests were performed with no wind. Post-fire investigations report that fire can also grow on the surface, spreading laterally and specifically vertically, and expose other components on the wall such as windows and under -eave vents to flames, as demonstrated in Figure 12 (Insurance Institute for Business & Home Safety, 2020; Maranghides et al., 2015; Quarles et al., 2013).

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Exterior Wall Covering/Cladding: While a 6 -in. vertical clearance protects a wall from embers, more action is needed to provide protection from flames. Their geometry makes walls suitable recipients of radiation and flame contact in WUI fires. The spread of flame through walls can be slow, but surface flame spread on combustible siding occurs quickly. This exposes windows and eaves to direct flame contact and can begin the cascade of damage for a home. Noncombustible cladding eliminates the chance of such flame exposures.

Figure 12. IBHS post-fire investigations show: (a) fire penetration through combustible cladding and vertical flame spread during the Glass Fire (2020) in Napa and Sonoma Counties, California, likely from a burning vehicle; (b) radiant heat damage from surrounding fires (located more than 50 ft away) damaged the vinyl siding, also during the Glass Fire (2020); (c) T1-11 siding ignited due to fire from surrounding vegetation, likely suppressed by first responders during the Camp Fire (2018) in Butte County, California; (d) fire penetration through combustible cladding during the Waldo Canyon Fire (2012) in El Paso County, Colorado (Maranghides et al., 2015); and (e) in the laboratory, the siding of the building ignited during IBHS’s full-scale wind- driven building-to-building fire spread tests.
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Exterior Glass (Windows, Skylights, and Glass Within Doors) Windows and other glazing create a discontinuity in the cladding of a building. The cavity and edge effects at the discontinuities cause some inevitable installation vulnerabilities (Jensen, 2013 ; Manzello & Suzuki, 2021; Šadauskienė et al., 2022). Hence, the entire opening (windowpane[s], window frames, and fasteners) are vulnerable to radiative and convective heating, as displayed in Figure 13. Studies show that a thermal insult results in a temperature gradi ent between different parts of the window assembly and can cause different types of failure (Cuzzillo & Pagni, 1998; Gao et al., 2013). Double-paned windows are mandatory in many parts of the western United States for energy efficiency purposes. These windows are typically annealed glass and can withstand about 25 kW/m 2 of thermal exposure (Quarles & Gorham, 2020 ). In comparison to single-paned systems, double-paned systems consistently perform better in terms of fire barrier performance (Shields et al., 2005 ). If the windowpanes are tempered, the resistance increases to about 40 kW/m2 (Babrauskas, 2003), which is not an uncommon heat exposure in a wildfire.

Cohen (1995) exposed different types of windows to heat flux intensities of 9.3 kW/m2 , 13.6 kW/m2, and 17.7 kW/m2. Cohen reported that annealed single-paned windows and the outer pane of annealed double - paned windows broke at all three heat fluxes . The inner pane of annealed double -paned survived at 9.3 kW/m2. However, at higher heat fluxes, the second annealed pane of the double-paned windows also failed in 75% of the tests. Both single-paned and double-paned tempered windows survived.

Figure 13. Vulnerability of windows: (a) glazing collapsed in Neos Voutzas-Mati, Greece (2018) due to the combustion of a pine tree (Peñaloza et al., 2021), used with permission; (b) windows damaged by radiation from a burning fence about 10 ft away during the Glass Fire (2020) in Napa and Sonoma Counties, California, where the arrow indicates the direction of radiation; (c) the outer tempered pane of a window fell out during an IBHS full-scale test; (d) window damage following the Grass Valley Fire (2006) in San Bernardino County, California, due to a burning building about 40 ft away, documented by Stephen L. Quarles. © 2018 David Caballero
© Stephen L. Quarles
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IBHS’s recent findings show that the tempered outer pane of a double-paned window fails after about 10 min of exposure to the heat of a burning shed 30 ft away, and therefore it is necessary to have both panes tempered. The performance of a glazing unit depends on multiple factors including heat intensity, the air gap between the two panes, and breakage behavior of the first pane; these factors are not well understood (Wang et al., 2017).

Exterior Glass: Windows are vulnerable to flame contact and radiation. Multipaned windows are more resilient by providing multiple layers of protection before flames can penetrate the home. Tempered glass further increases resilience because of its higher resistance to radiation.

Exterior Doors
Like other parts of the building envelope, exterior doors can be exposed to flames, radiant heat, and embers. NIST’s post-Waldo Canyon Fire (2012) investigation in El Paso County, Colorado, reports doors as a frequent damaged component of the building (Maranghides et al., 2015). Maintaining a proper defensible space around the building reduces the potential thermal insults from flames. However, embers can still accumulate at the base of a door and potentially penetrate through the door jamb. IBHS’s post-Marshall Fire (2021) investigation in Boulder County, Colorado, showed limited damage to exterior doors due to ember accumulation at the base, as can be seen in Figure 14a. Figure 14b demonstrates ignition of the door jamb due to ember penetration of a home during research experiments at the IBHS Research Center.

Figure 14. (a) Post-Marshall Fire (2021) investigation in Boulder County, Colorado, showing evidence of ignition from an accumulation of embers and debris at the base of the door; (b) Embers charred the threshold during the Victorian Bushfire (2009) in Australia (Leonard, 2009), used with permission; (c) Embers ignite the door jamb at the IBHS Research Center. a
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This highlights the importance of the door assembly rather than the door itself. It should be mentioned that most of the evidence regarding external doors is anecdotal and more research in this area is needed.

Exterior Doors: Flames are less likely to reach exterior doors if there is proper defensible space around the home. However, wind -blown embers may still accumulate at the base of a door or penetrate small openings around the door and ig nite the door jamb. Similar to other components, the entire door assembly should be mitigated. Fire -rated doors are the most practical solution due to the lack of noncombustible door assemblies (door jamb) on the market.

Bay Windows
Existence of combustible materials, either accumulated debris, plants, or other fuels, adds a vulnerability to bay windows. Similar to low -elevation decks, bay windows trap debris as well as heat and embers due to their geometry. The evidence around bay windows is anecdotal and limited to post-event investigations (Maranghides et al., 2015 ). In the wake of the Glass Fire (2020) in Napa and Sonoma Counties, C alifornia, IBHS investigated this vulnerability. As shown in Figure 1 5, the vegetation underneath the open bay window was mostly consumed, while the vegetation beyond it was less so.

Enclosed Space Underneath Bay Windows: The geometry of bay windows traps heat underneath them.

While field evidence of ignitions is anecdotal, enclosing this area with noncombustible materials eliminates the risk.

Figure 15. Heat trapped underneath bay windows caused the vegetation in this area to burn disproportionally to its surroundings during the Glass Fire (2020) in Napa and Sonoma Counties, California.

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Takeaways
Outdoor fire behavior, especially in the WUI where fuels are more diversified, is a highly complex phenomenon dominated by embers, which attack communities during wildfires. Depending on the condition of the recipient fuels that embers land on, the characteristics of the embers themselves, and environmental conditions, embers can burn out, start small flames, or grow to large flames. Embers, small flames, and large flames all pose different threats to homes. Large flames radiate enough energy to ignite combustible building materials without coming in contact with the building. However, small flames need to be in very close proximity or even touching the building component to ignite them.

Vulnerable homes in the path of wildfires may become fuel for the fire with devastating, long-term impacts on communities. Due to the variety of possible ignition scenarios, a single hardening strategy is not effective at reducing the chance homes ignite. A systematic approach is necessary to harden homes against embers and flames because the mitigations against each are different.

Embers threaten a home directly and indirectly. Embers can start small spot fires near homes, which often propagate and can indirectly ignite a home. To minimize the threat of direct ignition by embers, a properly maintained Class A roof is required. It is necessary for all vents to have a mechanism that minimizes ember entry into the building. The footprint of a home should have a 6-in. noncombustible vertical clearance to limit direct contact between rolling, burning debris and any combustible components of the exterior wall.

To minimize the threat of indirect ember ignition, maintained defensible space is needed, with special attention given to the development and maintenance of Zone 0.

Tall flames rad iate substantial heat, spread rapidly , and are more difficult to suppress . However, their spread can be predicted more easily. Several factors affect the radiant heat intensity emitted by flames including their height, width, thickness, and the distance be tween the flame and surrounding fuels . Tall flames require vertically oriented fuel so noncombustible or fire-resistant materials are best suited to limit the possibility of tall flames. Increasing the distance between the potential source and the potential target is another effective way to reduce the spread of fire.

To protect a home from flames, all main vertical surfaces of the home, namely siding, windows, and exterior doors should be held to the highest fire resistance standard. Back-to-back fence rows should be removed.

The eaves and area beneath bay windows should be enclosed to minimize heat trapping in these areas.

Deck assemblies should be noncombustible or have solid walking surfaces with no gaps.

A tiered system of home hardening developed using the current state of the science in wildfire mitigation includes a foundational systemic protection of a home against embers and an additional layer of systemic protection to guard against vulnerabilities to flame exposure. As IBHS and others continue research, new findings must be considered for updates to this functional 2 -tiered systematic approach. While no home is fire-proof, systematically applying known mitigation strategies will reduce th e chance a home is lost in a wildfire.

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NIST Technical Note 2205

WUI Structure/Parcel/Community
Fire Hazard Mitigation Methodology

Alexander Maranghides
Eric D. Link
Steven Hawks
Jim McDougald
Stephen L. Quarles
Daniel J. Gorham
Shonali Nazare

This publication is available free of charge from:

https://doi.org/10.6028/NIST.TN.2205

NIST Technical Note 2205

WUI Structure/Parcel/Community
Fire Hazard Mitigation Methodology

Alexander Maranghides
Eric D. Link
Shonali Nazare
Engineering Laboratory, NIST

Steven Hawks
Jim McDougald
California Department of Forestry and Fire Protection (CAL FIRE)

Stephen L. Quarles
Daniel J. Gorham
Insurance Institute for Business & Home Safety (IBHS)

This publication is available free of charge from:
https://doi.org/10.6028/NIST.TN.2205

March 2022

U.S. Department of Commerce
Gina M. Raimondo, Secretary

National Institute of Standards and Technology
James K. Olthoff, Performing the Non-Exclusive Functions and Duties of the Under Secretary of Commerce for Standards and Technology & Director, National Institute of Standards and Technology

Certain commercial entities, equipment, or materials may be identified in this document in order to describe an experimental procedure or concept adequately.

Such identification is not intended to imply recommendation or endorsement by the National Institute of Standards and Technology, nor is it intended to imply that the entities, materials, or equipment are necessarily the best available for the purpose.

NIST policy is to use the International System of Units (SI) in all publications.

However, in this document, units are presented in the system prevalent in the relevant discipline, although in some cases more than one system of units may be presented.

National Institute of Standards and Technology Technical Note 2205 Natl. Inst. Stand. Technol. Tech. Note 2205, 77 pages (March 2022) CODEN: NTNOEF

This publication is available free of charge from:
https://doi.org/10.6028/NIST.2205

iii
This publication is available free of charge from: https://doi.org/10.6028/NIST.TN.2205 Abstract
In the last twenty years, wildland-urban interface (WUI) fires have grown in severity and size. The structures destroyed by WUI fires have devastated entire communities and have cost billions of dollars while significantly impacting the social fabric and economic well- being of entire regions. Structure losses are attributed to exposures from both embers (firebrands) and fire (radiation and/or convection). As structure losses continue to increase, there is a growing need for a comprehensive hazard assessment and mitigation methodology to harden appropriate structures and parcels effectively and efficiently against ember and fire exposures. To address this need, the National Institute of Standards and Technology (NIST), the California Department of Forestry and Fire Protection (CAL FIRE), and the Insurance Institute for Business & Home Safety (IBHS) embarked on a sixteen-month collaborative effort, culminating in this Hazard Mitigation Methodology (HMM).

The HMM provides an implementable path forward by considering the spatial relationships between fuels, exposures, and hardening at the structure and parcel levels. The HMM demonstrates how complex structure hardening is, and how and why hazards associated with both fire and ember exposures need to be mitigated. By describing the relationships between exposure and hardening within the methodology, HMM highlights situations where structure hardening does not provide sufficient protection in the absence of parcel hardening. The HMM also addresses housing density, structure separation distance, and parcel layouts. The methodology was explicitly designed to address the current building stock, i.e., to solve retrofit challenges, and efforts were made to limit retrofit expenses. While the methodology was developed primarily for retrofits, the presented strategy can also be applied to new construction.

This science-based methodology uses the knowledge collected from post-fire field observations spanning a dozen years and tens of thousands of hours of field data integration and analysis. Additionally, the HMM utilizes the latest technical knowledge gained from laboratory and large-scale research in fire propagation and hazard mitigation in the WUI.

This report documents the methodology and addresses the critical issues of mitigation effectiveness at the parcel and community levels. The impacts of partial mitigation at the parcel and community level were addressed for different types of WUI communities.

Key words
community hazard reduction; disaster resilience; ember; firebrand; hazard mitigation; large outdoor fires; parcel hardening; retrofit; structure separation distance; wildfire; wildland- urban interface; WUI

iv
This publication is available free of charge from: https://doi.org/10.6028/NIST.TN.2205 Table of Contents
Abstract ................................................................................................................................... iii Table of Contents ................................................................................................................... iv List of Figures ......................................................................................................................... vi Glossary ................................................................................................................................ viii

1. Introduction ......................................................................................................................... 1

2. WUI Definition .................................................................................................................... 3

3. Defining WUI by Structure Separation Distance ............................................................ 7

4. WUI Hazard Mitigation Methodology ............................................................................ 16

4.1. Introduction .................................................................................................................. 16

4.2. Quantifying Ember and Fire Exposures ....................................................................... 17

4.2.1. Embers ................................................................................................................... 17

4.2.2. Fire ......................................................................................................................... 18

4.3. Structure Ignition Pathways ......................................................................................... 19

4.3.1. Impact of Parcel Boundaries on Code Application ............................................... 20

4.3.2. Impact of Linear Features on Fire Spread ............................................................. 21

4.3.3. Impact of Fuel Agglomeration on Fire Spread ...................................................... 23

5. Hazard Mitigation at the WUI ......................................................................................... 27

5.1. Using the HMM ........................................................................................................... 30

5.2. Fuels Spacing ............................................................................................................... 30

5.3. Fuel Density in Different WUI Types .......................................................................... 34

5.4. Factors Influencing Structure Survivability ................................................................. 40

5.4.1. Effects of Defensive Actions on Structure Survivability ...................................... 40

5.4.2. Impacts of Structure Mitigation Compliance on Structure Resilience .................. 41

5.4.3. Impacts of Community Mitigation Compliance on Community Resilience ......... 42

5.4.4. Effects of Housing Density on Mitigation Strategies ............................................ 43

6. Frequently Asked Questions ............................................................................................ 45

7. Comparison of this Hazard Mitigation Methodology with National and International WUI Codes ............................................................................................................................. 47

8. Summary ............................................................................................................................ 48 Acknowledgments ................................................................................................................. 52 References .............................................................................................................................. 53 Appendix A. Home Hardening Requirements ................................................................ 57 Appendix B. Comparison of Existing Codes and Standards ......................................... 65

v
This publication is available free of charge from: https://doi.org/10.6028/NIST.TN.2205 List of Tables
Table 1. WU
I definitions. ......................................................................................................... 6 Table 2. WUI Types classified by structure separation distance (SSD) and typical parcel size. ................................................................................................................................................... 8

Table 3. Structure and parcel hardening effectiveness. .......................................................... 29 Table 4. Parcel layout and fuel placement in different WUI Types visualized in Figures 17 through 20. .............................................................................................................................. 34

Table 5. Defensive actions identified in NIST post-fire case studies. ................................... 40 Table 6. HMM items completely included in selected existing WUI building codes. .......... 47

Table A. Structure and attached combustible hardening against ignition from embers. ....... 58 Table B. Surrounding parcel hazard mitigation – hardening structure and attached combustibles against ignition from fire (radiation, convection). ............................................ 62 Table C. Primary parcel hazard mitigation – hardening structure and attached combustibles against ignition from fire (radiation, convection). .................................................................. 63 Table D. Structure hazard mitigation – hardening structure and attached combustibles against ignition from fire (radiation, convection). .............................................................................. 64 Table E. Comparison of selected existing WUI building codes. ........................................... 66

vi
This publication is available free of charge from: https://doi.org/10.6028/NIST.TN.2205 List of Figures
Figure 1. The neighborhood of Coffey Park in Santa Rosa, CA is an example of WUI Type 2 (High Density Interface – Interior). For SI: 1 ft = 0.305 m, 1 ac = 0.4 ha. ............................... 9 Figure 2. An example of structure density of the Mountain Shadows neighborhood in Colorado Springs, CO is shown in Map Figure 13 from NIST TN 1910 [4] (units modified).

Insets show the highest density area (yellow) and associated lot size distribution. ............... 10

Figure 3. Varying structure separation distances in the Mountain Shadows neighborhood of Colorado Springs, CO are shown in Map Figure 14 from NIST TN 1910 [4] (units modified).

The inset highlights an area of very low SSD. For SI: 1 ft = 0.305 m, 1 ac = 0.4 ha. ............ 11

Figure 4. WUI Type 6: Low Density Intermix Rancho Santa Fe, CA. .................................. 12 Figure 5. WUI Type 6: Low Density Intermix, The Trails, Rancho Bernardo, CA. Note irrigated lawns, long paved driveways, pools and tennis courts. Some structure-to-structure distances are representative of Moderate Density Intermix (lower part of image). Also note limited high density non-irrigated vegetative loading. ........................................................... 13

Figure 6. WUI Type 6: Low Density Intermix: Concow, CA. Note the overall large SSD and structures located within the wildland vegetation. Note the imagery is taken after the 2018 Camp Fire................................................................................................................................ 14

Figure 7. WUI fire hazard mitigation is a balance between two input dials—reducing exposure and increasing structure hardening. ......................................................................... 17 Figure 8. Parcel-level combustible features that can contribute to various structure ignition pathways. Highlighted in white are hazards that NIST and IBHS have performed extensive study of.................................................................................................................................... 20

Figure 9. Existing codes are parcel centric. Residential structures are similarly located in Scenario A and B; however, the parcel division in Scenario A allows placement of an auxiliary structure too close to the neighboring primary structure when the parcels are considered independently........................................................................................................ 21

Figure 10. Illustration of numerous fire spread pathways among neighboring parcels via linear features and other combustibles. Inset photographs are from field observations and experiments. ............................................................................................................................ 22

Figure 11. Parallel western red cedar fences burning with an applied wind of 13 mi/h (6 m/s) (left two images) compared to a single burning fence (right). ................................................ 23

Figure 12. Spatial relationships between fuels on two adjacent parcels. Sheds are spaced appropriately from the residences and other fuels, except fences, on their respective lots.

However, Shed A-1 is too close to Residence B, and both sheds act as an agglomerated fuel package along the property border. The sheds and fences will substantially increase the exposures from the red highlighted area, igniting the structures. ........................................... 24

Figure 13. Fuel on Lot B is adequately spaced from Residence B; however, fuel is agglomerated at the fence, which opens the pathway to Residence A. Ignition on Lot B may still result in pathway shown, gazebo→fence→RV→Residence A, despite noncombustible fence attachments on both residences. .................................................................................... 25