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Council Memorandum
August 27, 2026
To:
From:
Via:
Re:
Honorable Mayor Blackburn and Members of the City Council Michael Calderwood, Fire Chief
Darcy Davidson, Fire Marshal
Mike Strong, Community De
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Geoff Patnoe, City Manager
Zone Zero Defensible Space ulations (Districts -All) {city ofCarlsbad Memo ID# 2026044 This memorandum provides an overview and impacts of "Zone Zero," the new mandatory defensible space regulations adopted by the California Board of Forestry and Fire Protection on August 19, 2026.
Background
CAL FIRE (the Office of the State Fire Marshal) determines and maps the severity of fire hazards for state and local jurisdictions. CAL FIRE released the final phase of its updated Fire Hazard Severity Zone maps in March 2025, after which local jurisdictions were required to officially adopt these mapped designations within their areas of responsibility.1 In Carlsbad, areas classified as very high fire hazard severity zones (VHFHSZ) were expanded in CAL FIRE's updated Fire Hazard Severity Zone map and now cover roughly one-third of the city-8,169 of 24,128 acres. This represents a 169% increase compared to the 2007 CAL FIRE maps. In practice, local jurisdictions are required to comply with state fire mitigation rules in these areas.
Around the same time (February 2025}, Governor Gavin Newsom issued an Executive Order (N-18-25} directing California Board of Forestry and Fire Protection (Board of Forestry) to accelerate the development and adoption of a new set of regulations that would effectively create "ember-resistant" zones around structures to mitigate wildfire risks.
Previously, California's defensible space requirements required property owners in designated VHFHSZ to maintain up to 100 feet of defensible space around structures within property boundaries. This area has been addressed through two progressively restrictive vegetation management zones, including the Oto 30-foot zone and the 30 to 100-foot zone. These defensible space requirements have been in place for decades and dictate how property owners must manage their yard areas through tree spacing, removing dead vegetation, and other precautions.
1 The city officially adopted CAL FIRE's updated Fire Hazard Severity Zone map on June 17, 2025, categorizing city areas into moderate, high, or very high wildfire risk. Additional background information is included in the June 10, 2025, City Council Staff Report.
Fire Department
2560 Orion Way I Carlsbad, CA 92010 I 442-339-2141 t
Council Memo -Zone Zero Defensible Space Regulations (Districts -All) August 27, 2026
On August 19, 2026, the Board of Forestry approved the Zone Zero regulations, which effectively replaced the above referenced standards. Zone Zero is a new category of defensible space around any occupied structure in the VHFHSZ intended to help prevent wildfire from reaching the structure, especially from wind-driven embers. The regulations implement AB 3074 (2020}, SB 504 (2024}, and AB 1455 (2025), which amended Public Resources Code section 4291 and Government Code section 51182. The regulation establishes a five-foot ember-resistant zone surrounding occupied structures located in the local responsibility area VHFHSZ. They add "Zone Zero" to California's existing defensible space framework, in which Zones 1 and 2 already cover Oto 30-feet and 30 to 100-feet.
The Zone Zero rules will take effect after the Office of Administrative Law (OAL} review and filing, anticipated for early to mid-September 2026. Zone Zero regulations will apply immediately to all new building permits upon the regulations' effective date, and then to existing structures over a phased-in period of three to five years after the effective date.
Discussion
The Board of Forestry's approval of Zone Zero represents a significant change in California's approach to defensible space by establishing a specific regulatory focus on the first five feet surrounding structures. The regulations provide an important opportunity to strengthen the city's existing wildfire mitigation efforts and improve the likelihood that homes will survive ember exposure during a wildfire.
What is Zone Zero?
Zone Zero is the area within five feet of a structure, measured from exterior walls and attached decks, stairs, or pergolas. The purpose of the regulation is to reduce the likelihood that embers will ignite combustible materials immediately adjacent to a structure and subsequently result in direct flame contact, radiant heat exposure, or ignition of the structure itself.
The adopted rule:
• Prohibits combustible materials in Zone Zero, including woody vegetation, bark and wood chip mulch, accumulated leaves and other vegetative debris, and requires roofs and gutters to be kept clear.
• Prohibits wooden fences attached to the structure. Requires fences and gates to have a five-foot noncombustible section where they attach to the structure. • Allows existing trees to remain, subject to maintenance. • Allows well-maintained, low, non-woody plants and lawns in the outer part of Zone Zero.
The effective date:
The new regulations will roll out in phases, as reflected below.2 2 Because the phase clocks run from the effective date, the exact calendar dates depend on when the OAL completes its review.
Council Memo -Zone Zero Defensible Space Regulations (Districts -All} August 27, 2026
• Phase 1 -immediately, on the effective date: All new structures in the VHFHSZ must comply upon the effective date, which is when the OAL approves, anticipated for early to mid-September 2026. All building permit applications filed with the city on or after the effective date are subject to the newly adopted regulations. • Phase 2 -within three years: All existing structures in the VHFHSZ must remove unpermitted combustible items within five feet of a home in the VHFHSZ. This includes removing combustible materials, cleaning gutters, trimming trees, and removing dead plants.
• Phase 3 -within five years: All existing structures in the VHFHSZ must replace combustible attached fences and gates, address vegetation under and around combustible decking and patios, provide under-deck enclosures, remove or replace vegetation in the under-eave safety zone, etc.
The phased approach gives the Fire Department time to develop support programs that help property owners comply with the new rules.
Next Steps
Given the significance of these changes and the number of residents impacted (nearly 10,000 residents), the city is committed to providing education, guidance, and support to help residents timely navigate the new regulations.
Community Education and Outreach
The Fire Department is working closely with the city's Communications & Engagement Department to implement a coordinated, multi-channel outreach effort. Planned activities include:
• Direct outreach to affected property owners, including targeted notification to residential and commercial properties within VHFHSZ.
• Educational resources, including a dedicated Zone Zero webpage, handouts and checklists, frequently asked questions, visual examples and an educational video. • Community engagement through a virtual town hall meeting, Community Connection events, HOA briefings, Public Safety Open House and other opportunities to provide information and answer questions.
• Courtesy property evaluations to help residents and businesses understand Zone Zero and identify steps they can take to prepare their properties. • Ongoing communications through social media and other city and Fire Department channels to share guidance and provide updates as implementation moves forward. • Internal education and coordination to ensure Fire Department personnel, city leadership, and other customer-facing staff are equipped with consistent information when responding to community questions.
Council Memo -Zone Zero Defensible Space Regulations (Districts -All) August 27, 2026
The overall approach is intended to make the transition as clear and manageable as possible while positioning the Fire Department as a resource for affected community members throughout the process. The campaign will give residents adequate time to understand the requirements, make informed property improvements, and incorporate Zone Zero into broader home-hardening and wildfire preparedness efforts.
Community Development Department Outreach to Customers
• Direct outreach to building permit applicants and permit holders to inform them about the new rules (Zone Zero Phase 1) and how and when they would apply to new structures in the VHFHSZ. All projects under construction before the OAL effective date may continue under existing approvals until completion. All projects in plan check prior to the OAL effective date have one year to complete the plan review process and obtain a building permit.
• Educational resources will be provided on line and in-person at the Development Services counter, including Zone Zero handouts and checklists, frequently asked questions, etc.
Projects under construction now may still want to consider removing combustible materials away from occupied structures to reduce out-of-pocket expenses for hardscaping, fence replacement, etc., in Zone Zero phases 2 and 3.
The Fire Department and Community Development Department will continue to monitor the state's rulemaking and implementation guidance and will return to the City Council with additional recommendations regarding local implementation, policy updates, staffing, inspection processes, and public outreach, as necessary.
cc: Sheila Cobian, Assistant City Manager
Cindie McMahon, City Attorney
Jeff Murphy, Deputy City Manager, Community Services
Christie Calderwood, Police Chief
Paz Gomez, Deputy City Manager, Public Works
Jesse Sanchez, Building Official
Scott Nightingale, City Planner
Jennifer True, Senior Assistant City Attorney
Amy Ventetuolo, Communication & Engagement Director
Jason Haber, Intergovernmental Affairs Director