____________________________________________________________________________________
FOR CITY CLERK ONLY
Council Meeting:
Disposition:
Agenda Item: 5.a
Meeting Date: May 20, 2024
SAN RAFAEL CITY COUNCIL AGENDA REPORT
Department: Community Development
Prepared by: Don Jeppson, AIA CBO
Chief Building Official
Cory Bytof
Sustainability Program Manager
City Manager Approval: ______________
TOPIC: ORDINANCE AMENDING GREEN BUILDING CODES
SUBJECT: AN ORDINANCE AMENDING TITLE 12 (BUILDING REGULATIONS) OF THE SAN
RAFAEL MUNICIPAL CODE, BY AMENDING THE CALIFORNIA ENERGY CODE, THE 2022 CALIFORNIA GREEN BUILDING STANDARDS CODE FOR ELECTRIC VEHICLE CHARGERS, THE 2022 CALIFORNIA MECHANICAL CODE, AND THE 2022 CALIFORNIA PLUMBING CODE; ADDING A NEW CHAPTER 12.360 WITH ADMINISTRATIVE AND PROGRAM REGULATIONS ON MODEL REACH CODES;
AND ADOPTING FINDINGS OF FACT SUPPORTING THE AMENDMENTS TO THE CODES.
RECOMMENDATION:
Waive further reading of the Ordinance, refer to it by title only and introduce the Ordinance.
BACKGROUND:
The State of California Code of Regulations Title 24 construction codes are updated and published on a three-year cycle. The California Building Standards Commission publishes the triennial codes, and State law mandates that these codes become effective throughout California 180 days after the publication date. The current cycle of State construction codes became effective on January 1, 2023. Local jurisdictions are permitted to further amend the published codes to address local climatic, geological, or topographical conditions. On November 21, 2022, the City Council adopted the Title 24 State Building Code in its entirety with minor amendments.
Each three-year code cycle, the State also updates the Green Building section of the Title 24 codes and provides potential Green Building “reach” codes to local jurisdictions that go above the State code. These reach codes are encouraged to adopt more stringent local amendments to help drive greenhouse gas (GHG) reductions and inform future State code updates. Often, these more stringent reach codes include stronger energy and water efficiency requirements, among other things. On December 5, 2022, the City Council adopted local green building reach codes requiring enhanced electric vehicle charging requirements for new construction as well as requirements precluding the use of natural gas in new residential development and precluding natural gas line extensions and expansions in existing residential SAN RAFAEL CITY COUNCIL AGENDA REPORT / Page: 2
properties, among other things. Due to the 9th Circuit decision in the California Restaurant Association v. City of Berkeley case, staff recommends repealing those portions of the code precluding the use of gas in new residential development and precluding gas line extensions and expansions in existing residential properties, among other things. The proposed ordinance reflects these changes.
The State develops “intervening codes” mid-way between the three-year code updates, which typically have minor adjustments to the codes for various reasons. Those intervening codes automatically go into effect halfway through the code cycle without any action required by local jurisdictions. However, on occasion, these intervening codes are more significant, as is the case this year. Staff recommends updating our local codes to reflect some of those changes since some of them affect the City’s electric vehicle reach code.
Finally, when the City Council adopted the last round of green building reach codes in 2022, staff was directed to analyze reach code options for existing buildings since the City is mostly built out and will need to address emissions from its existing building stock to meet Climate Action Plan goals. Staff has been researching and developing an existing building renovation reach code with the help of community members, including representatives from our Planning Commission and Design Review Board.
The proposed ordinance would amend Title 12 of the City’s local Building Standards codes to include these new reach codes and make minor adjustments to the new State requirements to accommodate the City’s existing electric vehicle charger requirements, which are in some cases more stringent than the State. These amendments would also remove the prior natural gas prohibitions in the City’s previous reach code since a legal challenge occurred in the interim that now precludes such a requirement. This challenge was to the City of Berkeley in which the 9th Circuit Court determined that Berkeley’s prohibition on the installation of new gas pipeline connections was preempted by federal law. By extension, this applies to all local jurisdictions, including San Rafael.
Attachment 1 is the complete ordinance being proposed. Below is a brief summary of each of these code areas to be amended:
2022 Green Building Standards Code for Electric Vehicle Chargers: The provisions of this code apply to the installation of electric vehicle charging infrastructure, including equipment, fixtures, and fittings, including receptacles, charging equipment, software, and load management.
New chapter 12.360 – Single Family Model Reach Code – FlexPath: The provisions of this new chapter of the code specify additional energy efficiency and renewable energy measures for additions, alterations, and remodels of Covered Single-Family Projects.
After the introduction of this ordinance and public hearing, the ordinance would return to the City Council for final adoption at the next regularly scheduled meeting on June 3, 2024. After final adoption, the ordinance with these code amendments would be effective as soon as approved by the California Energy Commission, sometime after July 1, 2024, and most likely before September 2024. Building permit applications filed with the City prior to the effective date would not be subject to these amendments, nor the gas line prohibitions in the previous reach code.
ANALYSIS:
The staff recommendation requires amendments to four sections of Title 12 of the San Rafael Municipal Code as described below.
California Mechanical Code and Plumbing Code Amendments.
SAN RAFAEL CITY COUNCIL AGENDA REPORT / Page: 3
The purpose of the changes to the California Mechanical and Plumbing Codes is to remove from Title 12 previous amendments prohibiting gas on new construction and limiting gas expansion on existing singlefamily dwellings, thereby returning the codes to their base original language and requirements. This proposed ordinance adds language to Title 12, indicating that the City has no local amendments to the California Mechanical or Plumbing Codes. This method and format of indicating in Title 12 building codes that have not been amended specifically helps the community to identify clearly what has been amended or not amended by the City. This format and method have been used in the last two State code cycles and has been supported by the community.
California Green Building Code Amendments
The purpose of the changes to the California Green Building Standards Code Amendments is to incorporate new intervening code requirements for electric vehicle charging infrastructure into our local electric vehicle charging infrastructure reach codes. Since our local reach codes are more robust in some cases and we refer applicants to our local code this will make it easier to administer for both applicants and staff.
California Energy Code Amendments
The purpose of the changes to the California Energy Code is twofold. First, this amendment removes the City’s prior reach code amendment that disallows gas infrastructure in most new construction and additional gas infrastructure for existing single-family homes. The second purpose of these changes is to reduce the greenhouse gas (GHG) emissions associated with the renovation of existing single-family homes, including town homes and duplexes, by requiring additional energy efficiency measures for projects over 500 square feet in size. The requirements would apply to larger projects that often trigger a variety of codes, including mechanical, electrical, and plumbing. These extend far beyond a typical bathroom or kitchen remodel and instead apply to things like additions and renovations of multiple rooms in a building. They would also apply to accessory dwelling units (ADUs) but not to junior accessory dwelling units (JADUs) since ADUs are greater than 500 square feet.
Staff recommend a new approach, called the “Flex Path”, whereby project applicants will have the choice to select from a table of measures that reduce energy use in buildings. This can be found on page 5 of the ordinance labeled as Table 12.360A. To comply with this policy, an applicant will identify the required target score that applies to their home’s construction year at the top of the table. Then, they are free to install any combination of measures from the table that adds up to that required target score. These scores were developed with the assistance of two local architects and builders who have served on the Planning Commission and Design Review Board. The target scores were set to ensure that projects can meet the totals easily enough without having to choose electrical appliances while also ensuring significant energy savings and, in most cases, ongoing utility cost savings as well. These cost savings are demonstrated in Attachment 2, the California Codes and Standards Cost Effectiveness Study. The Codes and Standards team also developed a Frequently Asked Questions document, which can be found in Attachment 3.
The proposed new reach code for existing building renovations is similar to those adopted by the County of Marin and the Towns of Fairfax and San Anselmo, with some differences to better meet the needs of the City’s residents and building community. For example, San Rafael’s target scores are slightly lower than those of the County. Also, San Rafael maintains the State-recommended building vintages and different scores for each, while the County requires the same score regardless of a home’s vintage. In addition, to capture more projects, the City chose to reduce the square footage threshold from the 750 square feet the County is using to 500 square feet. All of these changes were carefully selected in consultation with community advisors and the State Codes and Standards Team and were reviewed by an ad hoc subcommittee consisting of Councilmembers Bushey and Llorens Gulati. More information on SAN RAFAEL CITY COUNCIL AGENDA REPORT / Page: 4
the policy development, including discussions on co-benefits and social equity, can be found in Attachment 4.
The Community & Economic Development department approves between 40-60 of these types of projects annually. It is estimated that enacting these reach codes would reduce emissions from these buildings by between 10-22% compared to not complying with our reach code. This reach code is intended as a way to begin to address existing buildings in a moderate fashion with the ability to learn as it is applied and to be able to enhance the Flex Path with other interventions or increase the target scores as time goes on. As part of staff’s commitment to equity, flexibility, and accessibility, there are exceptions built in as well as ways to give credit for energy efficiency measures already completed by applicants in prior projects. For example, if an applicant installed a solar system in the past several years that meets the requirements of the table, they would get credit for that. In addition, this Flex Path is seen as a means to encourage applicants to consider all the ways they can achieve energy and emissions reductions, including through air sealing, renewable energy installations, and the switch to electrical systems when appropriate.
Additionally, the ordinance includes a “catch-all” exemption which ensures that any one gas appliance is not prohibited by the ordinance. If a proposed project effectively results in the preclusion of the use of an appliance covered by the EPCA, the building official may waive any requirements of the ordinance causing such effective prohibition.
COMMUNITY ENGAGEMENT:
The City participated in a Steering Committee for a County of Marin-led “model reach code” development process, which resulted in the current reach code proposal. The Committee engaged and garnered feedback from individuals from a wide range of industries and organizations through surveys, interviews, focus groups, and meetings. They received feedback from city, town, and County staff; community-based organizations including environmental, affordable housing, senior/aging-in-place, and equity priority advocates; building community members including developers, architects, realtors, contractors, and Marin Builders Association; utilities including MCE and PG&E; and town and city commission, subcommittee, and City Council members. In addition, City staff have worked closely with the State Codes team and two local architects and builders in developing this proposal.
FISCAL IMPACT:
There is no fiscal impact associated with this action.
ENVIRONMENTAL REVIEW:
The proposed ordinance has been determined to be exempt from the California Environmental Quality Act (CEQA), pursuant to 14 CCR Section 15061(b)(3) since it can be seen with certainty that the adoption of this Ordinance would not have the potential for causing a significant effect on the environment. (14 Cal. Code Regs. Section 15061(b)(3), ‘general rule’ provision). The Ordinance is also exempt from the requirements of CEQA pursuant to CEQA Guidelines sections 15307 and 15308 as an action by a regulatory agency taken to protect the environment and natural resources.
OPTIONS:
The City Council has the following options to consider on this matter:
1. Consider public comment/testimony and introduce the Ordinance for adoption as proposed.
2. Consider public comment/testimony and introduce the Ordinance with amendments as directed by the Council.
SAN RAFAEL CITY COUNCIL AGENDA REPORT / Page: 5
3. Do not introduce the Ordinance and provide alternative directions to staff.
RECOMMENDED ACTION:
Waive further reading of the ordinance, refer to it by title only and introduce the Ordinance.
ATTACHMENTS:
1. Ordinance
2. California Codes and Standards Cost Effectiveness Study
3. FAQs: Single Family FlexPath Reach Codes
4. Policy Snapshot: Building Reach Code Proposal for Existing Construction 1 ORDINANCE NO.
AN ORDINANCE OF THE SAN RAFAEL CITY COUNCIL AMENDING TITLE 12 (BUILDING
REGULATIONS) OF THE SAN RAFAEL MUNICIPAL CODE, BY AMENDING THE CALIFORNIA ENERGY CODE, THE 2022 CALIFORNIA GREEN BUILDING STANDARDS CODE FOR ELECTRIC VEHICLE CHARGERS, THE 2022 CALIFORNIA MECHANICAL CODE, AND THE 2022 CALIFORNIA PLUMBING CODE; ADDING A NEW CHAPTER 12.360 WITH ADMINISTRATIVE AND PROGRAM REGULATIONS ON MODEL REACH CODES; AND ADOPTING FINDINGS OF FACT SUPPORTING THE AMENDMENTS TO THE CODES.
THE CITY COUNCIL OF THE CITY OF SAN RAFAEL DOES ORDAIN AS FOLLOWS:
DIVISION 1. AMENDMENTS TO TITLE 12 OF THE MUNICIPAL CODE.
Section 1. Repeal Ordinance No. 2022
Ordinance No. 2022 of the San Rafael City Council amending Chapters 12.235, 12.245, and
12.250 of Title 12 of the San Rafael Municipal Code is hereby repealed.
Section 2. Adoption of and Amendments to Construction Codes Chapters 12.220, 12.235, 12.245, and 12.250 of the San Rafael Municipal Code are hereby amended to read as follows:
CHAPTER 12.220 – CALIFORNIA ENERGY CODE AMENDMENTS
12.220.010 General. For purpose of this Chapter:
Deleted language from the base code has been stricken through.
Replacement language to the base code has been underlined.
12.220.020 Amendments. The 2022 California Energy Code is amended or modified as follows:
Amend Section 150.0 to read as follows:
Single-family residential buildings shall comply with the applicable requirements of Sections 150(a) through 150.0(v); in addition, Covered Single Family Projects shall comply with the applicable requirements of Section 12.360 of the SRMC.
NOTE: The requirements of Sections 150.0(a) through 150.0(v) apply to newly constructed buildings. Sections 150.2(a) and 150.2(b) specify which requirements of Sections 150.0(a) through 150.0(v) also apply to additions or alterations, with the exception that Covered Single Family Projects shall also be required to comply with Section 12.360 of the SRMC.
CHAPTER 12.235 - CALIFORNIA GREEN BUILDING STANDARDS CODE AMENDMENTS
12.235.010 General. For purpose of this Chapter:
2 Deleted language from the base code has been stricken through.
Replacement language to the base code has been underlined.
12.235.020 Amendments. The 2022 California Green Building Standards Code is amended or modified as follows:
Delete Section 4.106.4.1 and replace in its entirety to read as follows:
4.106.4.1 New One- And Two-Family Dwellings and Town-Houses. For each dwelling unit, install a 40 ampere 208/240 volt dedicated EV branch circuit, capable of supporting Level 2 EVSE, terminating with a receptacle or an EV charger in close proximity to the vehicle charging area.
Delete Subsection 4.106.4.1.1 in its entirety.
Subsection 4.106.4.2 [unchanged].
Amend Subsection 4.106.4.2.2 item 1(b) to read as follows (other subsections remains unchanged):
b. Multifamily parking facilities. Forty (40) Eighty-five (85) percent of the total number of parking spaces shall be equipped with low power Level 2 EV charging receptacles. EV charging receptacles required by this section shall be located in at least one assigned parking space per dwelling unit where assigned parking is provided but need not exceed forty (40) eighty-five (85) percent of total number of assigned parking spaces provided on site.
Exception: Areas of parking facilities served by parking lifts, including but not limited to automated mechanical-access open parking garages as defined in the California Building Code; or parking facilities otherwise incapable of supporting electric vehicle charging.
Amend Subsection 4.106.4.2.2 item 2(b) to read as follows (other subsections remains unchanged):
b. Multifamily parking facilities. Ten (10) Fifteen (15) percent of the total number of parking spaces shall be equipped with Level 2 EV chargers. At least fifty (50) percent of the required EV chargers shall be equipped with J1772 connectors. Where common use parking or unassigned parking is provided, EV chargers shall be located in common use or unassigned parking areas and shall be available for use by all residents or guests.
CHAPTER 12.245 - CALIFORNIA MECHANICAL CODE AMENDMENTS
12.245.010 No amendments. The 2022 California Mechanical Code is not amended or modified.
CHAPTER 12.250 - CALIFORNIA PLUMBING CODE AMENDMENTS
12.250.010 No amendments. The 2022 California Plumbing Code is not amended or modified. 3 Section 3. Addition of new Chapter 12.360 with administrative and program regulations on Model Reach Code.
Chapter 12.360 of the San Rafael Municipal Code is hereby added to read as follows:
CHAPTER 12.360 – SINGLE FAMILY MODEL REACH CODE - FLEXPATH
12.360.010 Purpose. The purpose of this chapter is to specify additional energy efficiency and renewable energy measures for additions, alterations and remodels of Covered Single Family Projects.
12.360.020 Definitions. For the purpose of this chapter, the following definitions shall apply:
1. “Single Family Building” shall mean any of the following:
a. Residential building of Occupancy Group R-3 or under the California Residential Code with two or fewer dwellings.
b. A townhouse.
c. A building of Occupancy Group R-3.1, or
d. A building of Occupancy Group U when located on a residential site. e. JADUs or ADUs that are not part of multifamily.
2. “Covered Single Family Project” shall mean the addition, alteration, or remodel of a Single Family Building originally permitted for construction before 2011 that affects a floor area which exceeds 500 square feet of existing floor area and/or new floor area.
When any changes are made in the building, such as walls, columns, beams or girders, floor or ceiling joists and coverings (subfloor and drywall), roof rafters, roof diaphragms, foundations, piles or retaining walls or similar components, the floor area of all rooms affected by such changes shall be included in computing floor areas for purposes of applying this definition.
This definition does not apply to project scopes that are solely limited to any of the following: the replacement and upgrading of residential roof coverings, exterior wall finishes and/or floor finishes; alterations that add no more than 75 square feet of fenestration; alterations that add no more than 16 square feet of skylight area with a maximum U-factor of 0.55 and a maximum SHGC of 0.30; alterations that are limited to providing access for persons with disabilities; or voluntary state seismic retrofit program. A Covered Single Family Project shall not include a project that is considered to be a newly constructed building under the California Energy Code, Title 24, Part 6.
12.360.020 Scope. In addition to all requirements of the California Energy Code applicable to Single Family Building additions and alterations, the provision of this chapter shall apply to all Covered Single Family Projects.
12.360.020 Requirements. A Covered Single Family Project shall install a set of measures based on the building vintage from the Measure Menu in Table 12.360B, to achieve a total Measure Point Score that is equal to or greater than the Target Score in Table 12.360A. In addition, all mandatory measures listed in Table 12.360B shall be installed. Installed measures shall meet the specifications in Table 12.360C. 4 Building vintage is the year in which (1) a building permit for construction of the structure was submitted, as documented by building department records, or (2) a building permit was issued for an addition or alteration that satisfied the Performance Standards (California Energy Code, Title 24, Part 6, Section 150.1(b)) in effect at time of building permit issuance, whichever is later. Unless otherwise specified, the requirements shall apply to the entire dwelling unit, not just the additional or altered portion. Measures from the Measure Menu table that already exist in the home may be counted towards compliance with these requirements. Measures from the Measure Menu table that are to be installed to satisfy requirements under the California Energy Code, Title 24, Part 6, may not count towards compliance with these requirements. Where these requirements conflict with other California Energy Code requirements, the stricter requirements shall prevail.
Exceptions
1. If the applicant demonstrates that the Energy Budget of the building under the proposed project would be less than or equal to the Energy Budget of the building under the proposed project if it included any set of measures that would achieve compliance under this chapter 12.360. For purposes of this section “Energy Budget” shall have that meaning set forth in CBC section 100.1(b), as that section may be amended.
2. Mobile Homes, Manufactured Housing, or Factory-built Housing as defined in Division 13 of the California Health and Safety Code (commencing with Section 17000 of the Health and Safety Code).
3. Due to conditions specific to the project, if it is technically or economically infeasible to achieve compliance, the Building Official may reduce the Target Score and/or waive some or all of the mandatory requirements.
4. A measure that is necessary for compliance is prohibited because of a covenant or other deed restriction on the property, such as a homeowners association covenant.
5. The Building Official may reclassify the vintage of the building based on existing conditions.
6. An applicant who resides in the dwelling unit and qualifies as a low-income utility customer, or is the owner of the dwelling unit which is occupied by a dependent who qualifies as a low-income utility customer, may comply by either a) installing the duct sealing measure, the lighting measure and water heating package, or b) installing at least 1 kW of solar PV that meets the requirements of 2022 Title 24 Reference Appendix JA11. A low-income utility customer is anyone who is eligible for the California Alternative Rates for Energy (CARE) or Family Electric Rate Assistance Program (FERA) program. A Covered Single Family Project that consists solely of medically necessary improvements or solely of seismic safety improvements.
7. Nothing in this ordinance shall be construed so as to prohibit any one appliance covered by the Energy Policy and Conservation Act (EPCA) (42 U.S.C. 6292(a).) Should an applicant establish that this ordinance, as applied, prohibits a covered appliance in the applicant’s project, the Building Official shall waive that portion of the ordinance causing such prohibition.
5 Table 12.360A
Target Scores, Climate Zone 2
Building Vintage Pre-1978 1978-1991 1992-2010
Target Score 12 8 4
Table 12.360B
Measure Menu, Climate Zone 2
The measures in the Measure Menu shall conform to the specifications in Table 12.360C.
ID Measure
Building Vintage
Pre-1978 1978-1991 1992-2010
E1 Lighting Measures Mandatory
E2 Water Heating Package 1 1 1
E3 Air Sealing 2 2 1
E4 Attic Insulation (R-38) 6 2 1
E5 Duct Sealing 6 4 1
E6 New Ducts + Duct Sealing 9 6 2
E7 Windows 5 3 3
E8 Wall Insulation (R-13) 7 -- --
E10 Raised floor insulation (R-19)/(R-30) 8/10 8/9 --
FS1 Heat Pump Water Heater Replacing Gas 12 12 12
FS2 High Eff. Heat Pump Water Heater Replacing
Gas 14 14 14
FS3 Heat Pump Water Heater Replacing Electric 4 4 4
FS4 High Eff. Heat Pump Water Heater Replacing
Electric 6 6 6
FS5 Heat Pump Space Heater 23 18 15
FS6 High Eff. Heat Pump Space Heater 25 19 17
FS7 Dual Fuel Heat Pump Space Heater 20 15 14
FS8 Heat Pump Clothes Dryer 2 2 2
FS9 Induction Cooktop 1 1 1
PV Solar PV 16 15 13
6 Table 12.360C
Measure Specifications
ID Energy Measure Specification
Energy Measures
E1 Mandatory - Lighting Measures – Replace all interior and exterior screw-in incandescent, halogen, and compact fluorescent lamps with LED lamps. Install photocell controls on all exterior lighting luminaires.
E2 Water Heating Package: Insulate all accessible hot water pipes with pipe insulation a minimum of ¾ inch thick. This includes insulating the supply pipe leaving the water heater, piping to faucets underneath sinks, and accessible pipes in attic spaces or crawlspaces. Upgrade fittings in sinks and showers to meet current California Green Building Standards Code (Title 24, Part 11) Section 4.303 water efficiency requirements.
Exception: Upgraded fixtures are not required if existing fixtures have rated or measured flow rates of no more than ten percent greater than 2022 California Green Building Standards Code (Title 24, Part 11) Section 4.303 water efficiency requirements.
E3 Air Sealing: Seal all accessible cracks, holes, and gaps in the building envelope at walls, floors, and ceilings. Pay special attention to penetrations including plumbing, electrical, and mechanical vents, recessed can light luminaires, and windows. Weather-strip doors if not already present. Verification shall be conducted following a prescriptive checklist that outlines which building aspects need to be addressed by the permit applicant and verified by an inspector. Compliance can also be demonstrated with blower door testing conducted by a certified HERS Rater no more than three years prior to the permit application date that either: a) shows at least a 30 percent reduction from pre-retrofit conditions; or b) shows that the number of air changes per hour at 50 Pascals pressure difference (ACH50) does not exceed ten for Pre-1978 vintage buildings, seven for 1978 to 1991 vintage buildings and five for 1992-2010 vintage buildings. If combustion appliances are located within the pressure boundary of the building, conduct a combustion safety test by a professional certified by the Building Performance Institute in accordance with the ANSI/BPI-1200-S-2017 Standard Practice for Basic Analysis of Buildings, the Whole House Combustion Appliance Safety Test Procedure for the Comfortable Home Rebates Program 2020 or the California Community Services and Development Combustion Appliance Safety Testing Protocol.
E4 R-38 Attic Insulation: Attic insulation shall be installed to achieve a weighted assembly Ufactor of 0.025 or insulation installed at the ceiling level shall have a thermal resistance of R-38 or greater for the insulation alone. Recessed downlight luminaires in the ceiling shall be covered with insulation to the same depth as the rest of the ceiling. Luminaires not rated for insulation contact must be replaced or fitted with a fire-proof cover that allows for insulation to be installed directly over the cover.
Exception: In buildings where existing R-30 is present and existing recessed downlight luminaires are not rated for insulation contact, insulation is not required to be installed over the luminaires.
E5 Duct Sealing: Air seal all space conditioning ductwork to meet the requirements of the California Energy Code 150.2(b)1E. The duct system must be tested by a HERS Rater no more than three years prior to the Covered Single Family Project permit application date to verify the duct sealing and confirm that the requirements have been met. This measure may not be combined with the New Ducts and Duct Sealing measure in this Table.
7 Exception: Buildings without ductwork or where the ducts are in conditioned space.
E6 New Ducts, R-6 insulation + Duct Sealing: Replace existing space conditioning ductwork with new R-6 ducts that meet the requirements of 2022 Title 24 Section 150.0(m)11. This measure may not be combined with the Duct Sealing measure in this Table. To qualify, a preexisting measure must have been installed no more than three years before the Covered Single Family Project permit application date.
E7 Windows: Replace at least 50% of existing windows with high performance windows with an area-weighted average U-factor no greater than 0.30.
E8 R-13 Wall Insulation: Install wall insulation in all exterior walls to achieve a weighted Ufactor of 0.102 or install wall insulation in all exterior wall cavities that shall result in an installed thermal resistance of R-13 or greater for the insulation alone.
E9 Reserved for future use
E10 R-19 / R-30 Floor Insulation: Raised-floors shall be insulated such that the floor assembly has an assembly U-factor equal to or less than U-0.037 / U-0.034 or shall be insulated between wood framing with insulation having an R-value equal to or greater than R-19 / R30.
Fuel Substitution Measures
FS1 Heat Pump Water Heater (HPWH) Replacing Gas: Replace existing natural gas water heater with a heat pump water heater.
FS2 High Efficiency Heat Pump Water Heater (HPWH) Replacing Gas: Replace existing natural gas water heater with heat pump water heater with a Northwest Energy Efficiency Alliance (NEEA) Tier 3 or higher rating.
FS3 Heat Pump Water Heater (HPWH) Replacing Electric: Replace existing electric resistance water heater with a heat pump water heater.
FS4 High Efficiency Heat Pump Water Heater (HPWH) Replacing Electric: Replace existing electric resistance water heater with heat pump water heater with a Northwest Energy Efficiency Alliance (NEEA) Tier 3 or higher rating.
FS5 Heat Pump Space Heater: Replace all existing gas and electric resistance primary space heating systems with an electric-only heat pump system.
FS6 High Efficiency Heat Pump Space Heater: Replace all existing gas and electric resistance primary space heating systems with one of the following:
A. A ducted electric-only heat pump system with a SEER2 rating of 16.5 or greater, an EER2 rating of 12.48 or greater and an HSPF2 rating of 9.5 or greater; or B. A ductless mini-split heat pump system with a SEER2 rating of 14.3 or greater, an EER2 rating of 11.7 or greater and an HSPF2 rating of 7.5 or greater FS7 Dual Fuel Heat Pump Space Heater: Either
A. Replace all existing gas and electric resistance primary heating systems with a hybrid gas and electric heat pump system, or
B. Install an electric-heat pump system in tandem with a gas furnace and install controls to operate the heat pump to use the existing gas furnace for backup heat only.
FS8 Heat Pump Clothes Dryer: Replace existing electric resistance clothes dryer with heat pump dryer with no resistance element and cap gas line.
FS9 Induction Cooktop: Replace all existing gas and electric resistance stove tops with inductive stove top and cap the gas line.
Solar PV and Electric-Readiness Measures
PV Solar PV + Electric Ready Pre-Wire: Install a solar PV system that meets the requirements of California Energy Code Section 150.1(c)14. In addition, upgrade the 8 panelboard to meet the requirements of Item ER1 in this Table and install any one other measures from Item ER2.
DIVISION 2. FINDINGS.
The San Rafael City Council finds that the scientific evidence has established that natural gas combustion as well as leakage occurring during natural gas procurement, transportation, storage, and distribution produce significant greenhouse gas emissions that contribute to global warming, climate change and sea level rise.
California Health and Safety Code Sections 17958.5, 17958.7, and 18941.5 require that findings be made in order to change or modify building standards found in the California Building Standards Code based on local climatic, geologic, or topographic conditions. Therefore, the San Rafael City Council hereby finds that these changes or modifications to the California Green Building Standards Code, the California Plumbing Code and the California Mechanical Code as adopted in Chapter 12.200 of the San Rafael Municipal Code are reasonably necessary because of the following local climatic, geological, and topographical conditions:
I. Climatic conditions:
a) Most of the annual rainfall in San Rafael occurs during the winter, it receives no measurable precipitation between May and October. During this time, temperatures average between 70 and 90 degrees. These conditions eliminate most of the moisture in the natural vegetation and heavily wooded hillsides. The area also suffers periodic droughts that can extend the dry periods to other months of the year. These conditions can be further exacerbated by occasional off-shore hot, dry, Santa-Ana winds; all of which contribute to an elevated fire hazard.
Further, global warming due to climate change is making these conditions worse, extending the dry period by a full month in the spring and summer and exacerbating drought conditions.
b) The seasonal climatic conditions during the late summer and fall create severe fire hazards to the public health and welfare in the City. The hot, dry weather can result in wildland fires on the brush covered slopes adjacent to the majority of neighborhoods west of highway 101.
c) Local amendments to the municipal code pursuant to this ordinance are reasonably necessary to achieve greenhouse gas emission reductions that reduces the risks of climate shocks such as wildfires and drought, which will then reduce risks of physical damage to critical infrastructure, property loss, and loss of life. In addition, reducing electricity demand and encouraging on-site renewable energy and emergency backup reduces fire potential and reduces health and safety impacts to residents during public safety power shut offs. d) Most of the annual rainfall in San Rafael occurs during the winter, and some portions of San Rafael are subject to tidal influences, thus there are times that flooding conditions occur in low-lying areas. Much of San Rafael from downtown to the Canal, along San Pedro Road and south to the Richmond San Rafael Bridge 9 are lower than high tide and susceptible to flooding and sea level rise caused by climate change. San Rafael is expected to experience one foot of additional sea level rise in the coming decades. Local amendments to the municipal code pursuant to this ordinance are reasonably necessary to achieve greenhouse gas emission reductions that reduces the risks of flooding due to sea level rise, which will then reduce risks of physical damage to critical infrastructure, property loss, and loss of life.
II. Geologic conditions:
a) San Rafael lies near several earthquake faults, including the very active San Andreas Fault, there are significant potential hazards such as road closures, fires, collapsed buildings, and isolation of residents requiring assistance. b) Many areas of the city, including some highly developed industrial and commercial areas, are located on bay alluvial soils which are subject to liquefaction in the event of an earthquake.
c) The City includes hillsides with narrow and winding access, which makes timely response by fire suppression and emergency response vehicles difficult. d) Local amendments to the municipal code are reasonably necessary to reduce natural gas use thereby reducing the potential for leaks as well as the potential for fires caused by leaks during seismic events.
III. Topographic conditions:
a) Much of San Rafael is located in hilly areas, and many of the residential areas are heavily landscaped, and many exist adjacent to hilly open space areas which are characterized by dry vegetation and have limited access. In addition, the steepness of grades located in the hills and canyons results in narrow and winding roads, and limited water supply, making timely access, rescue and firefighting activities by emergency providers difficult.
b) The major arterial route between San Francisco and Marin and Sonoma County areas, Highway 101, bisects the City of San Rafael; should that highway become impassable, alternative routes via surface streets in San Rafael may cause heavy traffic congestion, limiting emergency access.
More specifically, the above modified building standards are listed below with the corresponding climatic, geological, or topographical condition which necessitates the modification.
CEgC Section Numbers Climatic, geological and topographical condition 150.0. Ia, Ib, IIc, IIIa,
CalGreen Section Numbers
4.106.4.1. Ia, Ib, IIc, IIIa,
4.106.4.2.2 1(b) Ia, Ib, IIc, IIIa,
4.106.4.2.2. 2(b) Ia, Ib, IIc, IIIa,
Title 12 Municipal Code
12.360 Ia, Ib, IIc, IIIa,
10 DIVISION 3. CALIFORNIA ENVIRONMENTAL QUALITY ACT (CEQA) This Ordinance is exempt from the California Environmental Quality Act (CEQA), pursuant to 14 CCR Section 15061(b)(3), since it can be seen with certainty that the adoption of this Ordinance would not have potential for causing a significant effect on the environment. (14 Cal. Code Regs.
Section 15061(b)(3), ‘general rule’ provision). The Ordinance is also exempt from the requirements of CEQA pursuant to CEQA Guidelines sections 15307 and 15308 as an action by a regulatory agency taken to protect the environment and natural resources.
DIVISION 4. SEVERABILITY.
If any section, subsection, sentence, clause or phrase of this Ordinance is for any reason held to be invalid, such decision shall not affect the validity of the remaining portion of this Ordinance.
The City Council of the City of San Rafael hereby declares that it would have adopted the Ordinance and each section, subsection, sentence, clause or phrase thereof, irrespective of the fact that any one or more sections, subsections, sentences, clauses or phrases shall be declared invalid.
DIVISION 5. EFFECTIVE DATE OF ORDINANCE.
This Ordinance shall be published once, in full or in summary form, before its final passage, in a newspaper of general circulation, published and circulated in the City of San Rafael and shall be in full force and effective thirty (30) days after its adoption, upon approval of the California Energy Commission or the date of the California Building Standards Commission (CBSC) accepts the ordinance for filing, whichever is later. If published in summary form, the summary shall also be published within fifteen (15) days after the adoption, together with the names of those Council members voting for or against same, in a newspaper of general circulation published and circulated in the City of San Rafael, County of Marin, State of California.
THE FOREGOING ORDINANCE was first read and introduced at a regular meeting of the San Rafael City Council on the 20th day of May 2024, and was passed and adopted at a regular meeting of the San Rafael City Council on the 3
rd day of June 2024 by the following vote, to wit:
AYES: COUNCILMEMBERS:
NOES: COUNCILMEMBERS:
ABSENT: COUNCILMEMBERS:
______________________________
Kate Colin, Mayor
Attest:
_____________________________
LINDSAY LARA, City Clerk
Prepared by:
Alea German, Claudia Pingatore, Ada Shen, & Keith Saechao, Frontier Energy, Inc Misti Bruceri, Misti Bruceri & Associates, LLC
Prepared for:
Kelly Cunningham, Codes and Standards Program, Pacific Gas and Electric Last modified: 2024/04/26
Revision: 1.2
Attachment 2
Cost-Effectiveness Analysis: Single Family New Construction Legal Notice
This report was prepared by Pacific Gas and Electric Company and funded by the California utility customers under the auspices of the California Public Utilities Commission.
Copyright 2022, Pacific Gas and Electric Company. All rights reserved, except that this document may be used, copied, and distributed without modification.
Neither PG&E nor any of its employees makes any warranty, express or implied; or assumes any legal liability or responsibility for the accuracy, completeness or usefulness of any data, information, method, product, policy or process disclosed in this document; or represents that its use will not infringe any privatelyowned rights including, but not limited to, patents, trademarks or copyrights.
Acronym List
2023 PV$ – Present value costs in 2023
ACH50 – Air Changes per Hour at 50 pascals pressure
differential
ACM – Alternative Calculation Method
ADU – Accessory Dwelling Unit
AFUE – Annual Fuel Utilization Efficiency
B/C – Lifecycle Benefit-to-Cost Ratio
BEopt – Building Energy Optimization Tool
BSC – Building Standards Commission
CA IOUs – California Investor-Owned Utilities
CASE – Codes and Standards Enhancement
CBECC-Res – Computer program developed by the California Energy Commission for use in demonstrating
compliance with the California Residential Building
Energy Efficiency Standards
CFI – California Flexible Installation
CFM – Cubic Feet per Minute
CO2 – Carbon Dioxide
CPAU – City of Palo Alto Utilities
CPUC – California Public Utilities Commission
CZ – California Climate Zone
DHW – Domestic Hot Water
DOE – Department of Energy
DWHR – Drain Water Heat Recovery
EDR – Energy Design Rating
EER – Energy Efficiency Ratio
EF – Energy Factor
Cost-Effectiveness Analysis: Single Family New Construction GHG – Greenhouse Gas
HERS Rater – Home Energy Rating System Rater
HPA – High Performance Attic
HPWH – Heat Pump Water Heater
HSPF – Heating Seasonal Performance Factor
IECC – International Energy Conservation Code
IOU – Investor Owned Utility
kBtu – kilo-British thermal unit
kWh – Kilowatt Hour
LBNL – Lawrence Berkeley National Laboratory
LCC – Lifecycle Cost
LLAHU – Low Leakage Air Handler Unit
LSC – Long-term System Cost (2025 Title 24, Part 6 compliance metric) MF – Multifamily
NEEA – Northwest Energy Efficiency Alliance
NEM – Net Energy Metering
NPV – Net Present Value
NREL – National Renewable Energy Laboratory
PG&E – Pacific Gas and Electric Company
POU – Publicly-Owned-Utilities
PV – Photovoltaic
SCE – Southern California Edison
SDG&E – San Diego Gas and Electric
SEER – Seasonal Energy Efficiency Ratio
SF – Single Family
SMUD – Sacramento Municipal Utility District
SoCalGas – Southern California Gas Company
TDV – Time Dependent Valuation (2022 Title 24, Part 6 compliance metric) Therm – Unit for quantity of heat that equals 100,000 British thermal units Title 24 – Title 24, Part 6
TOU – Time-Of-Use
UEF – Uniform Energy Factor
VLLDCS – Verified Low Leakage Ducts in Conditioned Space ZNE – Zero-net Energy
Cost-Effectiveness Analysis: Single Family New Construction Summary of Revisions
Date Description Reference (page or section)
9/12/2022 Original Release (1.0) N/A
3/25/2024 Updated analysis (1.1) • New simulation results with latest CBECC-Res version (Section 2.1.1)
• Updated utility cost estimates using
recent utility tariff and net billing
tariff (Section 2.1.3)
• New measure costs for heat pumps,
batteries, and PV (Section 3.3)
• Revised packages (Section 3.4)
• Revised Results, Summary,
References, and Appendices
(Sections 4-7)
4/26/2024 Corrected errors (1.2) • Corrected incorrect results in Tables 16-19, 23, 26
Cost-Effectiveness Analysis: Single Family New Construction
TABLE OF CONTENTS
Executive Summary..........................................................................................................................................................1 1 Introduction................................................................................................................................................................4 2 Methodology and Assumptions...............................................................................................................................5
2.1 Analysis for Reach Codes..................................................................................................................................................... 5
2.1.1 Modeling ....................................................................................................................................................................... 5
2.1.2 Cost-effectiveness ........................................................................................................................................................ 5
2.1.3 Utility Rates................................................................................................................................................................... 7
2.2 Greenhouse Gas Emissions ................................................................................................................................................. 8
2.3 Energy Design Rating........................................................................................................................................................... 8 3 Prototypes, Measure Packages, and Costs............................................................................................................9
3.1 Prior Reach Code Research ................................................................................................................................................. 9
3.2 Prototype Characteristics...................................................................................................................................................... 9
3.3 Measure Definitions and Costs ........................................................................................................................................... 12
3.3.1 Efficiency, Solar PV, and Batteries ............................................................................................................................. 12
3.3.2 Electrification............................................................................................................................................................... 17
3.4 Measure Packages ............................................................................................................................................................. 22 4 Results......................................................................................................................................................................24
4.1 Compliance Results: All-Electric vs. Mixed Fuel Code Minimum ........................................................................................ 24
4.2 All-Electric Code Minimum Results ..................................................................................................................................... 26
4.3 All-Electric Efficiency, PV, and Battery Results................................................................................................................... 29
4.4 Mixed Fuel Results ............................................................................................................................................................. 31
4.5 Greenhouse Gas Reductions.............................................................................................................................................. 33
4.6 Sensitivity Analysis ............................................................................................................................................................. 35
4.6.1 CARE Rate Comparison ............................................................................................................................................. 36
4.6.2 Utility Infrastructure Cost Sensitivity............................................................................................................................ 38
4.6.3 Utility Rate Escalation................................................................................................................................................. 39 5 Summary ..................................................................................................................................................................42 6 References ...............................................................................................................................................................46 7 Appendices ..............................................................................................................................................................48
7.1 Map of California Climate Zones......................................................................................................................................... 48
7.2 Utility Rate Schedules......................................................................................................................................................... 49
7.2.1 Pacific Gas & Electric.................................................................................................................................................. 50
7.2.2 Southern California Edison ......................................................................................................................................... 57
7.2.3 Southern California Gas.............................................................................................................................................. 61
7.2.4 San Diego Gas & Electric............................................................................................................................................ 62
7.2.5 City of Palo Alto Utilities.............................................................................................................................................. 68
7.2.6 Sacramento Municipal Utilities District (Electric Only)................................................................................................. 70
7.2.7 Fuel Escalation Assumptions...................................................................................................................................... 72
7.3 Summary of Efficiency Measures........................................................................................................................................ 74
7.4 Summary of Applicable Prescriptive Base case Measures ................................................................................................. 76 Cost-Effectiveness Analysis: Single Family New Construction
LIST OF TABLES
Table 1: Utility Tariffs Used Based on Climate Zone ............................................................................................................................ 7 Table 2: Prototype Characteristics........................................................................................................................................................ 9 Table 3: Base case Characteristics of the Prototypes ........................................................................................................................ 11 Table 4: Base Package PV Capacities (kW-DC) ................................................................................................................................ 12 Table 5: Incremental Cost Assumptions: Efficiency, PV, and Battery Measures ................................................................................ 14 Table 6: Single Family IOU Total Natural Gas Infrastructure Costs.................................................................................................... 17 Table 7: Single Family CPAU Total Natural Gas Infrastructure Costs ................................................................................................ 18 Table 8: ADU Utility Infrastructure Total and Incremental Costs......................................................................................................... 18 Table 9: Effective Useful Lifetime (EUL) of Water Heating & Space Conditioning Equipment............................................................ 19 Table 10: Space Conditioning System Nominal Capacities ................................................................................................................ 20 Table 11: Space Conditioning System Incremental Costs (2023 PV$)............................................................................................... 20 Table 12: Heat Pump Water Heating System Incremental Costs (2023 PV$) .................................................................................... 21 Table 13: Single Family All-Electric Appliance Incremental Costs ...................................................................................................... 22 Table 14: Single Family Cost-Effectiveness: All-Electric Code Minimum............................................................................................ 27 Table 15: ADU Cost-Effectiveness: All-Electric Code Minimum.......................................................................................................... 28 Table 16: Single Family Cost-Effectiveness: Comparison of All-Electric Efficiency Only, PV, and Battery Packages ........................ 29 Table 17: ADU Cost-Effectiveness: All-Electric Energy Efficiency + Additional PV + Battery ............................................................. 30 Table 18: Single Family Cost-Effectiveness: Mixed Fuel Efficiency + PV + Battery............................................................................ 31 Table 19: ADU Cost-Effectiveness: Mixed Fuel Efficiency + PV + Battery ......................................................................................... 32 Table 20: Single Family Greenhouse Gas Reductions (metric tons) .................................................................................................. 33 Table 21: ADU Greenhouse Gas Reductions (metric tons) ................................................................................................................ 34 Table 22: On-Bill Cost-Effectiveness with CARE Tariffs: All-Electric Code Minimum ......................................................................... 36 Table 23: On-Bill Cost-Effectiveness with CARE Tariffs: Mixed Fuel Efficiency + PV+ Battery Package ........................................... 37 Table 24: Single Family Cost-Effectiveness Comparison with Range of Natural Gas Utility Infrastructure Costs: All-Electric Code Minimum........................................................................................................................................................................................ 38 Table 25: Cost-Effectiveness, 2025 LSC Basis: All-Electric Code Minimum ...................................................................................... 40 Table 26: Cost-Effectiveness, 2025 LSC Basis: Mixed Fuel Efficiency + PV + Battery ...................................................................... 41 Table 27: Summary of Single Family EDR1 Margins and Cost-Effectiveness .................................................................................... 44 Table 28: Summary of ADU EDR1 Margins and Cost-Effectiveness .................................................................................................. 45 Table 29: PG&E Baseline Territory by Climate Zone.......................................................................................................................... 50 Table 30: PG&E Monthly Gas Rate ($/therm)..................................................................................................................................... 50 Table 31: SCE Baseline Territory by Climate Zone ............................................................................................................................ 57 Table 32: SoCalGas Baseline Territory by Climate Zone ................................................................................................................... 61 Table 33: SoCalGas Monthly Gas Rate ($/therm) .............................................................................................................................. 61 Table 34: SDG&E Baseline Territory by Climate Zone ....................................................................................................................... 62 Cost-Effectiveness Analysis: Single Family New Construction Table 35: SDG&E Monthly Gas Rate ($/therm).................................................................................................................................. 62 Table 36: CPAU Monthly Gas Rate ($/therm)..................................................................................................................................... 68 Table 37: Real Utility Rate Escalation Rate Assumptions, CPUC En Banc and 2022 TDV Basis ...................................................... 72 Table 38: Real Utility Rate Escalation Rate Assumptions, 2025 LSC Basis ....................................................................................... 73 Table 39: All-Electric Single Family Efficiency Measures, Various Packages..................................................................................... 74 Table 40: Mixed Fuel Single Family Measures, Efficiency + PV + Battery Package........................................................................... 75 Table 41: Efficiency Measures for All ADU Packages ........................................................................................................................ 75 Table 42 Prescriptive Envelope, PV, and Battery Measures by Climate Zone.................................................................................... 76 Table 43 Prescriptive HVAC Measures by Climate Zone ................................................................................................................... 77 Table 44 Prescriptive Water Heating Measures by Climate Zone....................................................................................................... 77
LIST OF FIGURES
Figure 1: Single family all-electric home compliance impacts............................................................................................................. 24 Figure 2: ADU all-electric home compliance impacts.......................................................................................................................... 25 Figure 3: Single family four gas appliance home compliance impacts................................................................................................ 25 Figure 4: Map of California climate zones........................................................................................................................................... 48
Cost-Effectiveness Analysis: Single Family New Construction Executive Summary
1 California Energy Codes & Standards | A statewide utility program 2024-04-26 Executive Summary
The California Codes and Standards (C&S) Reach Codes program provides technical support to local governments considering adopting a local ordinance (reach code) intended to support meeting local and/or statewide energy efficiency and greenhouse gas (GHG) reduction goals. The program facilitates adoption and implementation of the code when requested by local jurisdictions by providing resources such as cost-effectiveness studies, model language, sample findings, and other supporting documentation.
This report documents cost-effectiveness analysis results for traditional new detached single family and detached accessory dwelling unit (ADUs) building types. It evaluates mixed fuel and all-electric package options in all sixteen California climate zones (CZs). Packages include combinations of efficiency measures, on-site renewable energy, and battery energy storage.
This analysis used two different metrics to assess the cost-effectiveness of the proposed upgrades. Both methodologies require estimating and quantifying the incremental costs and energy savings associated with each energy efficiency measure over a 30-year analysis period. On-Bill cost-effectiveness is a customer-based lifecycle cost (LCC) approach that values energy based upon estimated site energy usage and customer utility bill savings using today’s electricity and natural gas utility tariffs. Time Dependent Valuation (TDV) is the California Energy Commission’s LCC methodology, which is intended to capture the long-term projected cost of energy, including costs for providing energy during peak periods of demand, carbon emissions, grid transmission and distribution impacts. This is the methodology used by the Energy Commission in evaluating cost-effectiveness for efficiency measures in Title 24, Part 6.
The following are key takeaways and recommendations from the analysis.
Conclusions and Discussion:
• All-electric buildings have lower GHG emissions than mixed fuel buildings, due to the clean power sources currently available from California’s power providers as well as accounting for increased penetration of renewables in the future. Almost all the all-electric packages evaluated resulted in greater GHG emission savings than the mixed fuel packages, with the exception of the mixed fuel package with battery storage in climate zones with low heating loads.
• The Reach Codes Team found code-compliant all-electric new construction to be feasible and cost-effective based on TDV for single family homes in all cases except Climate Zone 16. • All-electric single family new construction was On-Bill cost-effective in all cases except Climate Zones 1, 3, 14, and 16.
• The all-electric ADU home was cost-effective based on TDV in all cases except in Climate Zones 3, 4, 13, and 14 where the higher cost of installing a ducted heat pump water heater (HPWH) instead of the prescriptively required gas tankless water heater exceed the resulting energy cost savings. In the other climate zones there were first cost savings for installing a heat pump space heater instead of a gas furnace, contributing to an overall TDV cost-effective result.
• Few cases were cost-effective On-Bill for the ADU.
• All-electric code minimum construction results in an increase in first year utility costs relative to a mixed fuel home, except for CPAU and SMUD where electricity rates are much lower than for the investor-owned utilities (IOUs). The addition of efficiency measures, market dominant HPWHs that meet the Northwest Energy Efficiency Alliance’s (NEEA’s) Advanced Water Heating Specification1, high efficiency heat pumps, increased solar photovoltaics (PV), and batteries all reduce utility costs, and a combination of these options was found to reduce annual utility costs relative to a mixed fuel home in all cases. 1 Refer to Section 0 for an explanation of HPWHs certified through NEEA’s Advanced Water Heating Specification, their market status, and how they compare to federal minimum efficiency standards.
Cost-Effectiveness Analysis: Single Family New Construction Executive Summary
2 California Energy Codes & Standards | A statewide utility program 2024-04-26 • Under the Net Biling Tariff (NBT)2, utility cost savings for increasing PV system size beyond code minimum are substantially less than what they were under prior net energy metering rules (NEM 2.0); however, savings are sufficient to be On-Bill cost-effective in all climate zones for the all-electric single family home. Coupling PV with battery systems increases utility cost savings as a result of improved on-site utilization of PV generation and fewer exports to the grid.
• Applying California Alternate Rates for Energy (CARE) rates in the IOU territories improves On-Bill costeffectiveness for all-electric buildings, as compared to the same case under standard rates, due to higher utility cost savings compared to a code compliant mixed fuel building also on a CARE rate. This is due to the CARE discount on electricity being higher than that on gas.
• If gas tariffs are assumed to increase substantially over time, in line with the escalation assumption from the 2025 LSC development, all-electric new construction was found to be On-Bill cost-effective in almost all scenarios over the 30-year analysis period. There is much uncertainty surrounding future tariff structures as well as escalation values. While it’s clear that gas rates are anticipated to increase, how much and how quickly is not known. Electricity tariff structures are expected to evolve over time, and the California Public Utilities Commission (CPUC) has an active proceeding to adopt an income-graduated fixed charge that benefits lowincome customers and supports electrification measures3. The CPUC will make a decision in mid-2024 and the new rates are expected to be in place later that year or in 2025. While the anticipated impact of this rate change is lower volumetric electricity rates, the rate design is not finalized. While lower volumetric electricity rates provide many benefits like incentivizing electrification, it also will make building efficiency measures harder to justify as cost-effective due to lower utility bill cost savings.
Recommendations:
• A reach code with a single performance target based on source energy (EDR1) can be structured to strongly encourage electrification. This approach requires equivalent performance for all buildings and allows mixed fuel buildings which minimizes the risk of violating federal preemption. Below are examples of how a reach code for single family homes could be set up based on the results summarized in Table 27. o A jurisdiction in Climate Zone 12 could set a performance target at an EDR1 margin of 11.5 (the EDR1 margin for the all-electric Code Minimum package). Any all-electric home meeting or exceeding the prescriptive requirements would comply, and a mixed fuel home would likely need to incorporate a combination of efficiency measures and a battery system to comply. o Similarly, a jurisdiction in Climate Zone 7 may consider setting a performance target of 2.8 EDR1 margin (also the EDR1 margin for the all-electric Code Minimum package). Any all-electric home meeting or exceeding the prescriptive requirements would comply, but a mixed fuel home would likely be able to comply with only a suite of above-code efficiency measures (no battery). Alternatively, a higher EDR1 margin target of 5 would incentivize more energy efficiency or additional PV for allelectric construction, and mixed fuel construction would likely need to incorporate a battery system to comply.
o A jurisdiction in Climate Zone 16 may want to set a performance target at an EDR1 margin of 20.5 (the EDR1 margin for the mixed fuel efficiency + PV + battery package). This would establish a target that a mixed fuel home could cost-effectively meet, likely only after incorporating a combination of efficiency measures and a battery system, and that an all-electric home could easily meet. • The 2022 Title 24 code’s new source energy metric combined with the heat pump baseline encourage allelectric construction, providing an incentive that allows for some amount of prescriptively required building efficiency to be traded off, still meeting minimum code compliance. This compliance benefit for all-electric homes highlights a unique opportunity for jurisdictions to incorporate efficiency into all-electric reach codes.
Efficiency and electrification have symbiotic benefits and are both critical for decarbonization of buildings. As demand on the electric grid is increased through electrification, efficiency can reduce the negative impacts of 2 Refer to Section 2.1.3 for discussion on NBT and NEM
3 https://www.cpuc.ca.gov/industries-and-topics/electrical-energy/electric-costs/demand-response-dr/demand-flexibility-rulemaking Cost-Effectiveness Analysis: Single Family New Construction Executive Summary
3 California Energy Codes & Standards | A statewide utility program 2024-04-26 additional electricity demand on the grid, reducing the need for increased generation and storage capacity, as well as the need to upgrade upstream transmission and distribution equipment. The Reach Codes Team recommends that jurisdictions adopting a reach code for single family buildings also include an efficiency requirement with EDR1 margins at minimum consistent with the all-electric code minimum package results in Table 27.
• The code compliance margins for the ADU all-electric code minimum package are lower than for the single family prototype; code compliance and cost-effectiveness can be more challenging for smaller dwelling units.
As a result, the Reach Codes Team does not recommend EDR1 targets above those reported for the allelectric Code Minimum package in Table 28.
This report presents measures or measure packages that local jurisdictions may consider adopting to achieve energy savings and emissions reductions beyond what will be accomplished by enforcing minimum state requirements, the 2022 Building Energy Efficiency Standards (Title 24, Part 6), effective January 1, 2023.
Local jurisdictions may also adopt ordinances that amend different Parts of the California Building Standards Code or may elect to amend other state or municipal codes. The decision regarding which code to amend will determine the specific requirements that must be followed for an ordinance to be legally enforceable. For example, jurisdictions may amend Part 11 instead of Part 6 of the CA Building Code requiring review and approval by the Building Standards Commission (BSC) but not the California Energy Commission (Energy Commission). Reach codes that amend Part 6 of the CA Building Code and require energy performance beyond state code minimums must demonstrate the proposed changes are cost-effective and obtain approval from the Energy Commission. Although a cost-effectiveness study is only required to amend Part 6 of the CA Building Code, this study provides valuable context for jurisdictions pursuing other ordinance paths to understand the economic impacts of any policy decision. This study documents the estimated costs, benefits, energy impacts and greenhouse gas emission reductions that may result from implementing an ordinance based on the results to help residents, local leadership, and other stakeholders make informed policy decisions.
Model ordinance language and other resources are posted on the C&S Reach Codes Program website at LocalEnergyCodes.com. Local jurisdictions that are considering adopting an ordinance may contact the program for further technical support at [email protected]. In addition, jurisdictions in a CCA territory with rates or rate structures that are significantly different than IOU rates may email the program at [email protected] to request a custom analysis.
Cost-Effectiveness Analysis: Single Family New Construction Introduction
4 California Energy Codes & Standards | A statewide utility program 2024-04-26 1 Introduction
This report documents cost-effective combinations of measures that exceed the minimum state requirements, the 2022 Building Energy Efficiency Standards, effective January 1, 2023, for newly constructed single family buildings. This report was developed in coordination with the California Statewide Investor-Owned Utilities (CA IOUs) Codes and Standards Program, key consultants, and engaged cities—collectively known as the Reach Codes Team.
The analysis considers traditional detached single family and detached accessory dwelling unit (ADUs) building types and evaluates mixed fuel and all-electric package options in all sixteen California climate zones (CZs).4 Packages include combinations of efficiency measures, on-site renewable energy, and battery energy storage.
This report documents the key results and conclusions from the Reach Codes Team analysis. A full dataset of all results can be downloaded from the Local Energy Codes Resources5 webpage. Results alongside policy options and the potential citywide impacts for specific jurisdictions can also be explored using the Cost-effectiveness Explorer at https://explorer.localenergycodes.com/.
The California Building Energy Efficiency Standards Title 24, Part 6 (Title 24) (California Energy Commission, 2021a) is maintained and updated every three years by two state agencies: the California Energy Commission (Energy Commission) and the Building Standards Commission (BSC). In addition to enforcing the code, local jurisdictions have the authority to adopt local energy efficiency ordinances—or reach codes—that exceed the minimum standards defined by Title 24 (as established by Public Resources Code Section 25402.1(h)2 and Section 10-106 of the Building Energy Efficiency Standards). Local jurisdictions must demonstrate that the requirements of the proposed ordinance are costeffective and do not result in buildings consuming more energy than is permitted by Title 24. In addition, the jurisdiction must obtain approval from the Energy Commission and file the ordinance with the BSC for the ordinance to be legally enforceable.
The Department of Energy (DOE) sets minimum efficiency standards for equipment and appliances that are federally regulated under the National Appliance Energy Conservation Act, including heating, cooling, and water heating equipment (E-CFR, 2020). Since state and local governments are prohibited from adopting higher minimum efficiencies than the federal standards require — herein referred to as federal preemption — the focus of this study is to identify and evaluate cost-effective packages that do not include high efficiency heating, cooling, and water heating equipment.
High efficiency appliances are often the easiest and most affordable measures to increase energy performance. While federal preemption limits reach code mandatory requirements for covered appliances, in practice, builders may install any package of compliant measures to achieve the performance requirements.
4 See Appendix 7.1 Map of California Climate Zones for a graphical depiction of climate zone locations. 5 https://localenergycodes.com/content/resources/?q=newly%20constructed%20buildings:%20efficiency%20and%20electrification Cost-Effectiveness Analysis: Single Family New Construction Methodology and Assumptions
5 California Energy Codes & Standards | A statewide utility program 2024-04-26 2 Methodology and Assumptions
2.1 Analysis for Reach Codes
This section describes the approach to calculating cost-effectiveness including benefits, costs, metrics, and utility rate selection.
2.1.1 Modeling
The Reach Codes Team performed energy simulations using software approved for 2022 Title 24 Code compliance analysis, CBECC-Res 2022.3.0.
The general approach applied in this analysis is to evaluate performance and determine cost-effectiveness of various energy efficiency upgrade measures, individually and as packages, in single family buildings. Using the 2022 baseline as the starting point, prospective measures and packages were identified and modeled in each of the prototypes to determine the projected energy use (therm and kWh) and compliance impacts. A large set of parametric runs were conducted to evaluate various options and develop packages of measures that met or exceeded minimum code performance. The analysis utilized a Python based parametric tool to automate and manage the generation of CBECCRes input files. This allowed for quick evaluation of various efficiency measures across multiple climate zones and prototypes and improved quality control. The batch process functionality of CBECC-Res was utilized to simulate large groups of input files at once.
2.1.2 Cost-effectiveness
2.1.2.1 Benefits
This analysis used two different metrics to assess cost-effectiveness of the proposed upgrades. Both methodologies require estimating and quantifying the incremental costs and energy savings associated with each energy efficiency measure. The main difference between the methodologies is the manner in which they value energy and thus the cost savings of reduced or avoided energy use:
Utility Bill Impacts (On-Bill): Customer-based lifecycle cost (LCC) approach that values energy based upon estimated site energy usage and customer utility bill savings using today’s electricity and natural gas utility tariffs. Total savings are estimated over a 30-year duration and include discounting of future costs and energy cost inflation.
Time Dependent Valuation (TDV): Energy Commission LCC methodology, which is intended to capture the total value or cost of energy use over 30 years. This method accounts for long-term projected costs, such as the cost of providing energy during peak periods of demand, and other societal costs, such as projected costs for carbon emissions as well as grid transmission and distribution impacts. This metric values energy use differently depending on the fuel source (natural gas, electricity, and propane), time of day, and season. For example, electricity used (or saved) during peak periods has a much higher value than electricity used (or saved) during off-peak periods due to the less inefficient energy generation sources providing peak electricity (Horii, Cutter, Kapur, Arent, & Conotyannis, 2014). This is the methodology used by the Energy Commission in evaluating cost-effectiveness for efficiency measures in Title 24, Part 6.
2.1.2.2 Costs
The Reach Codes Team assessed the incremental costs of the measures and packages over a 30-year lifecycle.
Incremental costs represent the equipment, installation, replacement, and maintenance costs of the proposed measure relative to the 2022 Title 24 Standards minimum requirements or standard industry practices. Present value of replacement cost is included only for measures with lifetimes less than the 30-year evaluation period.
In calculating On-Bill cost-effectiveness, incremental first costs were assumed to be financed into a mortgage or loan with a 30-year loan term and four percent interest rate. Financing was not applied to future replacement or maintenance costs. In calculating TDV cost-effectiveness, incremental first costs were not assumed to be financed into a mortgage or loan.
Cost-Effectiveness Analysis: Single Family New Construction Methodology and Assumptions
6 California Energy Codes & Standards | A statewide utility program 2024-04-26
2.1.2.3 Metrics
Cost-effectiveness is presented using net present value (NPV) and benefit-to-cost (B/C) ratio metrics.
NPV Savings: The lifetime NPV savings is reported as a cost-effectiveness metric; Equation 1 demonstrates how this is calculated. If the net savings of a measure or package is positive, it is considered cost-effective. Negative savings represent net costs.
B/C Ratio: Ratio of the present value of all benefits to the present value of all costs over 30 years (present value of benefits divided by present value of costs). The criteria benchmark for cost-effectiveness is a B/C ratio greater than one. A value of one indicates the present value of the savings over the analysis period is equivalent to the present value of the lifetime incremental cost of that measure. A value greater than one represents a positive return on investment. The B/C ratio is calculated according to Equation 2.
Equation 1
𝑁𝑁𝑁𝑁𝑁𝑁 𝑆𝑆𝑆𝑆𝑆𝑆𝑆𝑆𝑆𝑆𝑆𝑆𝑆𝑆 = 𝑃𝑃𝑃𝑃 𝑃𝑃 𝑃𝑃 𝑣𝑣𝑣𝑣 𝑜𝑜𝑜𝑜 𝑙𝑙 𝑏𝑏 − 𝑃𝑃𝑃𝑃 𝑃𝑃 𝑃𝑃 𝑣𝑣𝑣𝑣 𝑜𝑜𝑜𝑜 𝑙𝑙 𝑐𝑐 Equation 2
𝐵𝐵 − − 𝐶𝐶 𝑅𝑅 = 𝑃𝑃𝑃𝑃 𝑃𝑃 𝑃𝑃 𝑣𝑣𝑣𝑣 𝑜𝑜𝑜𝑜 𝑙𝑙 𝑏𝑏
𝑃𝑃𝑃𝑃 𝑃𝑃 𝑃𝑃 𝑣𝑣𝑣𝑣 𝑜𝑜𝑜𝑜 𝑙𝑙 𝑐𝑐
Improving the efficiency of a project often requires an initial incremental investment. In most cases the benefit is represented by annual On-Bill utility or TDV savings, and the cost is represented by incremental first cost and replacement costs. However, some packages result in initial construction cost savings (negative incremental cost), and either energy cost savings (positive benefits), or increased energy costs (negative benefits). In cases where both construction costs and energy-related savings are negative, the construction cost savings are treated as the ‘benefit’ while the increased energy costs are the ‘cost.’ In cases where a measure or package is cost-effective immediately (i.e., upfront construction cost savings and lifetime energy cost savings), B/C ratio cost-effectiveness is represented by “>1”.
The lifetime costs or benefits are calculated according to Equation 3.
Equation 3
𝑜𝑜𝑜𝑜 𝑙𝑙 𝑐𝑐 𝑜𝑜 𝑏𝑏 = �(𝐴𝐴 𝑐𝑐 𝑜𝑜 𝑏𝑏 )𝑡𝑡
(1 + )𝑡𝑡
𝑛𝑛
𝑡𝑡=0
Where: n = analysis term in years
• r = discount rate
The following summarizes the assumptions applied in this analysis to both methodologies. • Analysis term of 30 years
• Real discount rate of three percent
TDV is a normalized monetary format and there is a unique procedure for calculating the present value benefit of TDV energy savings. The present value of the energy cost savings in dollars is calculated by multiplying the TDV savings (reported by the CBECC-Res simulation software) by a NPV factor developed by the Energy Commission (see (Energy + Environmental Economics, 2020)). The 30-year residential NPV factor is $0.173/kTDV kBtu for the 2022 code cycle.
Equation 4
• 𝑇𝑇𝑇𝑇 𝑜𝑜𝑜𝑜 𝑙𝑙 𝑏𝑏 = 𝑇𝑇𝑇𝑇 𝑒𝑒 ∗ 𝑁𝑁𝑁𝑁𝑁𝑁
Cost-Effectiveness Analysis: Single Family New Construction Methodology and Assumptions
7 California Energy Codes & Standards | A statewide utility program 2024-04-26
2.1.3 Utility Rates
In coordination with the CA IOU rate team (comprised of representatives from Pacific Gas and Electric (PG&E), Southern California Edison (SCE) and San Diego Gas and Electric (SDG&E)) and two Publicly-Owned-Utilities (POUs) (Sacramento Municipal Utility District (SMUD) and City of Palo Alto Utilities (CPAU)), the Reach Codes Team determined appropriate utility rates for each climate zone in order to calculate utility costs and determine On-Bill costeffectiveness for the proposed measures and packages. The utility tariffs, summarized in Table 1, were determined based on the most prevalent active rate in each territory. Utility rates were applied to each climate zone based on the predominant IOU serving the population of each zone, with a few climate zones evaluated multiple times under different utility scenarios. Climate Zones 10 and 14 were evaluated with both SCE/SoCalGas and SDG&E tariffs since each utility has customers within these climate zones. Climate Zone 5 is evaluated under both PG&E and SoCalGas natural gas rates. Two POU or municipal utility rates were also evaluated: SMUD in Climate Zone 12 and CPAU in Climate Zone 4.
Some community choice aggregations (CCAs) have utility rates that are very similar to IOU rates, often within $0.02 per kWh. For these CCA customers, total utility costs will be very similar to those calculated in this study and the results from this study will generally apply. The study results cannot be easily applied to CCAs with rates that do not closely track the IOU rates or municipal utilities outside of SMUD and CPAU.
First-year utility costs were calculated using hourly electricity and natural gas output from CBECC-Res and applying the utility tariffs summarized in Table 1. Annual costs were also estimated for IOU customers eligible for the CARE tariff discounts on both electricity and natural gas bills. Appendix 7.2 Utility Rate Schedules includes details of each utility tariff. For cases with onsite generation (i.e. solar photovoltaics (PV)), the approved Net Billing Tariff (NBT) was applied along with monthly service fees and hourly export compensation rates for 20246. In December 2022, the California Public Utilities Commission (CPUC) issued a decision adopting NBT as a successor to prior net energy metering rules (NEM 2.0) that went into effect April of 2023.7 The ADU was assumed to have separate electric and gas meters from the main house.
Table 1: Utility Tariffs Used Based on Climate Zone
Climate
Zones
Electric / Gas
Utility Electricity Tariff Natural GasTariff
IOUs
1-5,11-13,16 PG&E / PG&E E-ELEC G1
5 PG&E / SoCalGas E-ELEC GR
6, 8-10, 14, 15 SCE / SoCalGas TOU-D-PRIME GR
7, 10, 14 SDG&E / SDG&E EV-TOU-5 (TOU-ELEC for ADU
cases without PV systems8) GR
POUs
4 CPAU / CPAU E-1 G1
12 SMUD / PG&E R-TOD G1
Utility rates are assumed to escalate over time according to the CPUC 2021 En Banc hearings on utility costs through 2030 (California Public Utilities Commission, 2021a). Escalation rates through the remainder of the 30-year evaluation period are based on the escalation rate assumptions within the 2022 TDV factors. A second set of escalation rates were also evaluated to demonstrate the impact that utility cost changes over time have on cost-effectiveness. This utility rate escalation sensitivity analysis, presented in Section 4.6.3, was based on those used within the 2025 Long6 https://www.cpuc.ca.gov/-/media/cpuc-website/divisions/energy-division/documents/net-energy-metering-nem/nemrevisit/nbtmodel--12142022.xlsb 7 https://www.cpuc.ca.gov/nemrevisit 8 See Section 3.2 Prototype Characteristics for a description of ADU cases that don’t require solar PV prescriptively.
Cost-Effectiveness Analysis: Single Family New Construction Methodology and Assumptions
8 California Energy Codes & Standards | A statewide utility program 2024-04-26 term System Cost (LSC) factors (LSC replaces TDV in the 2025 code cycle) which assumed steep increases in gas rates in the latter half of the analysis period. See Appendix 7.2.7 Fuel Escalation Assumptions for details.
2.2 Greenhouse Gas Emissions
The analysis reports the greenhouse gas (GHG) emission estimates based on assumptions within CBECC-Res. There are 8,760 hourly multipliers accounting for time-dependent energy use and carbon based on source emissions, including renewable portfolio standard projections. There are two strings of multipliers—one for Northern California climate zones, and another for Southern California climate zones.9 GHG emissions are reported as average annual metric tons of CO2 equivalent over the 30-year measure analysis period.
2.3 Energy Design Rating
The 2019 Title 24 Code introduced California’s Energy Design Rating (EDR) as the primary metric to demonstrate compliance with the energy code for single family buildings. This EDR was based on the hourly TDV energy use from a building that is compliant with the 2006 International Energy Conservation Code (IECC) as the Reference Building. The Reference Building has an EDR score of 100 while a zero-net energy (ZNE) home has an EDR score of zero. While the Reference Building is used to set the scale for the rating, the Proposed Design is still compared to the Standard Design based on the Title 24 prescriptive baseline assumptions to determine compliance. In the 2022 Title 24 Code a second new EDR metric was introduced based on hourly source energy. The two EDR metrics are described below:
• EDR1 is calculated based on source energy.
• EDR2 is calculated based on TDV energy.
EDR1 has only one component, “Total EDR1” which represents source energy use for the entire building. EDR2 is composed of two components for compliance purposes: the “Efficiency EDR2”, which represents the energy efficiency features of a home, and the PV/Flexibility EDR2, which includes the effects of PV and battery storage systems. “Total EDR2” combines all energy use of the building including both the Efficiency and PV/Flexibility impacts. While the Efficiency EDR2 does not include the full impact of a battery system, it can include a self-utilization credit for batteries if certain conditions are met.
For a new, single family building to comply with the 2022 Title 24 Code, three criteria must be met:
1. The Proposed Total EDR1 must be equal to or less than the Total EDR1 of the Standard Design, and
2. The Proposed Efficiency EDR2 must be equal to or less than the Efficiency EDR2 of the Standard Design, and
3. The Proposed Total EDR2 must be equal to or less than the Total EDR2 of the Standard Design.
This concept, consistent with California’s “loading order” which prioritizes energy efficiency ahead of renewable generation, requires projects to meet a minimum Efficiency EDR2 before PV is credited but allows for PV to be traded off with additional efficiency when meeting the Total EDR2. A project may improve building efficiency beyond the minimum required and subsequently reduce the PV generation capacity necessary to achieve the required Total EDR2.
However, it may not increase the size of the PV system and trade this off with a reduction of efficiency measures.
Results from this analysis are presented as EDR Margin, a reduction in the EDR score relative to the Standard Design.
EDR Margin is a better metric to use than absolute EDR in the context of a reach code because absolute values vary based on the home design and characteristics such as size and orientation. This approach aligns with how compliance is reported for the 2019 and 2022 Title 24 Code. The EDR Margin is calculated according to Equation 5.
Equation 5
𝐸𝐸 𝑀𝑀 = 𝑆𝑆 𝑆𝑆𝑆𝑆𝑆𝑆𝑆𝑆 𝑆𝑆 𝐸𝐸 − 𝑃𝑃 𝑃𝑃 𝑃𝑃 𝐸𝐸
9 CBECC-Res multipliers are the same for CZs 1-5 and 11-13 (Northern California), while there is another set of multipliers for CZs 6-10 and 14-16 (Southern California).
Cost-Effectiveness Analysis: Single Family New Construction Prototypes, Measure Packages, and Costs
9 California Energy Codes & Standards | A statewide utility program 2024-04-26 3 Prototypes, Measure Packages, and Costs
This section describes the prototypes and the scope of analysis drawing from previous research where necessary, including the 2019 low-rise residential single family reach code study (Statewide Reach Codes Team, 2019).
3.1 Prior Reach Code Research
In 2019, the Reach Codes Team analyzed the cost-effectiveness of residential single family new construction projects for mixed fuel and all-electric packages (Statewide Reach Codes Team, 2019). Using this analysis, several cities and counties in California adopted local energy code amendments encouraging or requiring that low-rise residential new construction be all-electric. As there were few changes to the single family requirements, this analysis for the 2022 code cycle leveraged the work completed for the 2019 reports. Initial efficiency packages were based on the final packages from the 2019 research and were revised to reflect measure specifications and costs based on new data.
3.2 Prototype Characteristics
The Energy Commission defines building prototypes which it uses to evaluate the cost-effectiveness of proposed changes to Title 24 requirements. For the 2022 code cycle the Energy Commission used two single family prototypes, both of which were used in this analysis. Additional details on the prototypes can be found in the Alternative Calculation Method (ACM) Approval Manual (California Energy Commission, 2018).
Additionally, a detached new construction ADU prototype was developed to reflect recent trends in California construction related to the high cost of housing (TRC, 2021). ADUs are additional dwelling units typically built on the property of an existing single-family parcel. ADUs are defined as new construction in the energy code when they are ground-up developments, do not convert an existing space to livable space, and are not attached to the primary dwelling. The evaluated prototype is not representative of an attached ADU constructed as an addition to an existing home.
The Reach Codes Team leveraged prior research to define the detached ADU baseline and measure packages. The house size and number of bedrooms were based on data from a survey conducted by UC Berkeley’s Center for Community Innovation (UC Berkeley Center for Community Innovation, 2021). The survey found that the average square footage for new ADUs statewide is 615 square feet and that the majority (61 percent) of new ADUs have one bedroom.
Table 2 describes the basic characteristics of each prototype. The prototypes have equal geometry on all walls, windows and roof to be orientation neutral.
Table 2: Prototype Characteristics
Characteristic Single Family
One-Story
Single Family
Two-Story ADU
Conditioned Floor Area 2,100 ft2 2,700 ft2 625 ft2
Num. of Stories 1 2 1
Num. of Bedrooms 3 4 1
Window-to-Floor Area Ratio 20% 20% 19.2%
The Energy Commission’s protocol for the two single family prototypes is to weigh the simulated energy impacts by a factor that represents the distribution of single-story and two-story homes being built statewide. Consistent with this protocol, this study assumed 50 percent single-story and 50 percent two-story. Simulation results in this study are Cost-Effectiveness Analysis: Single Family New Construction Prototypes, Measure Packages, and Costs
10 California Energy Codes & Standards | A statewide utility program 2024-04-26 characterized and presented according to this ratio, which is approximately equivalent to a 2,400-square foot (ft2) house.10 ADU results are presented separately.
The methodology used in the analyses for each of the prototypical building types begins with a design that precisely meets the minimum 2022 prescriptive requirements (zero compliance margin). Table 150.1-A in the 2022 Standards (California Energy Commission, 2021a) lists the prescriptive measures that determine the baseline design in each climate zone. Other features are consistent with the Standard Design in the ACM Reference Manual (California Energy Commission, 2022), and are designed to meet, but not exceed, the minimum requirements. See Appendix 7.4 for a list of prescriptive values relevant to the measures explored in this analysis.
Table 3 describes additional characteristics as they were applied to the base case, or baseline, energy model in this analysis. In a shift from the 2019 Standards, the 2022 Standards apply a prescriptive fuel source for space heating and water, where one is gas-fueled and one is a heat pump depending on climate zone. This establishes a prescriptive heat pump baseline. In most climate zones the prescriptive base case includes a heat pump water heater and a natural gas furnace for space heating. In Climate Zones 3, 4, 13, and 14 this is reversed, where the base case has a heat pump space heater and natural gas tankless water heater.
Table 4 summarizes the PV capacities for the base case packages. 10 2,400 ft2 = (50% x 2,100 ft2) + (50% x 2,700 ft2)
Cost-Effectiveness Analysis: Single Family New Construction Prototypes, Measure Packages, and Costs
11 California Energy Codes & Standards | A statewide utility program 2024-04-26 Table 3: Base case Characteristics of the Prototypes
Characteristic Single Family ADU
Space
Heating/Cooling1,2
CZs 1-2,5-12,15-16: Natural gas furnace, split
AC 80 AFUE, 14.3 SEER2, 11.7 EER2
CZs 3-4,13-14: Split heat pump – 7.5 HSPF2,
14.3 SEER2, 11.7 EER2
Same as single family
Air Distribution Ductwork located in vented attic Same as single family Water Heater1,2
CZs 1-2,5-12,15-16: Heat pump water heater
(HPWH) UEF = 2.0 located in the garage
CZs 3-4,13-14: Natural gas tankless –
UEF = 0.81
Same equipment type as SF
except HPWH is located inside
the conditioned space with the
supply air ducted from outside
and exhaust air ducted to
outside.3
Hot Water
Distribution
Code minimum
CZs 1,16: Basic compact distribution credit Same as single family Cooking Natural Gas Same as single family
Clothes Drying Natural Gas Same as single family
PV System
Sized to offset 100% of electricity use for space
cooling, ventilation, lighting, appliance, & other
miscellaneous electric loads. Size differs by
climate zone ranging from 2.64 kW to 5.21 kW,
see Table 4.
PV is not required when the PV
system size required based on the
prescriptive calculations is less
than 1.8 kW, as is the case in
Climate Zones 1-9, 12, 14, and
16. In the other climate zones the
PV size ranges from 1.73 kW to
2.51 kW, see Table 4.
4 Foundation Slab-on-grade Same as single family
1 Equipment efficiencies are equal to minimum federal appliance efficiency standards. 2 AFUE = annual fuel utilization efficiency. SEER = seasonal energy efficiency ratio. EER = energy efficiency ratio.
HSPF = heating seasonal performance factor. UEF = uniform energy factor. 3 This version of CBECC-Res used in this analysis did not have the capability to directly model ducted HPWHs even though this configuration is called out as the Standard Design in the 2022 ACM (California Energy Commission, 2022). This was modeled by indicating that the tank is located within the conditioned space with the compressor unit located outside. 4 Exception 2 to Section 150.1(I)14 states that “no PV system is required when the minimum PV system size specified by section 150.1(c)14 is less than 1.8 kWdc.” In this analysis this exception is applied based on the sizes calculated per Equation150.1-C of Section 150.1(c)14. The performance software sizes the PV system based on the estimated energy use, which differs slightly from the prescriptive sizing. As a result, the baseline PV capacity from the performance software for Climate Zone 10 is less than 1.8 kWdc.
Cost-Effectiveness Analysis: Single Family New Construction Prototypes, Measure Packages, and Costs
12 California Energy Codes & Standards | A statewide utility program 2024-04-26 Table 4: Base Package PV Capacities (kW-DC)
Climate
Zone
Base Package
Single
Family ADU
CZ01 3.57 0
CZ02 3.03 0
CZ03 2.83 0
CZ04 2.91 0
CZ05 2.64 0
CZ06 2.65 0
CZ07 2.83 0
CZ08 3.11 0
CZ09 2.96 0
CZ10 3.17 1.73
CZ11 3.90 2.06
CZ12 3.14 0
CZ13 4.05 2.09
CZ14 3.15 0
CZ15 5.21 2.51
CZ16 2.93 0
3.3 Measure Definitions and Costs
Measures evaluated in this study fall into two categories: those associated with general efficiency — onsite generation (solar PV), and demand flexibility (batteries) — and those associated with building electrification. Furthermore, general efficiency measures are broken into those that are federally preempted and those that are not; see Section 1 for background information on preemption and Section 3.4 for details of measure packages evaluated in this study. The Reach Codes Team selected measures based on cost-effectiveness as well as decades of experience with residential architects, builders, and engineers along with general knowledge of the relative consumer acceptance of many measures.
The following sections describe the details and incremental cost assumptions for each of the measures. Incremental costs represent the equipment, installation, replacement, and maintenance costs of the proposed measures relative to the base case.11 Replacement costs are applied for roofs, mechanical equipment, PV inverters and battery systems over the 30-year evaluation period. Maintenance costs are estimated for PV systems, but not any other measures.
Costs were estimated to reflect costs to the building owner. All costs are provided as present value in 2023 (2023 PV$).
The Reach Codes Team obtained measure costs from distributors, contractors, literature review, and online sources such as Home Depot and RS Means. Contractor markups are incorporated. These are the Reach Codes Team’s best estimates of average costs statewide. However, it's recognized that local costs may differ, and that inflation and supply chain issues may also impact costs.
3.3.1 Efficiency, Solar PV, and Batteries
The following are descriptions of each of the efficiency, PV, and battery measures evaluated under this analysis and applied in at least one of the packages presented in this report, including how they compare to the current prescriptive requirements. Throughout this report, “Efficiency” measures refer specifically to the following non-preempted 11 All first costs are assumed to be financed in a mortgage and interest costs due to financing are included in the incremental costs.
See Section 2.1.2 for details.
Cost-Effectiveness Analysis: Single Family New Construction Prototypes, Measure Packages, and Costs
13 California Energy Codes & Standards | A statewide utility program 2024-04-26 measures. These measures are in addition to or in place of the relevant 2022 base case prototype characteristics outlined in Table 3, and their applicability to measure packages are summarized in Table 39 through Table 41. Table 5 summarizes the incremental cost assumptions for each of these measures.
Reduced Infiltration (ACH50): Reduce infiltration in single family homes from the default infiltration assumption of five (5) air changes per hour at 50 Pascals (ACH50) 12 by 40 percent to 3 ACH50. HERS rater field verification and diagnostic testing of building air leakage according to the procedures outlined in the 2022 Reference Appendices RA3.8 (California Energy Commission, 2021b).
Lower U-Factor Fenestration: Reduce window U-factor to 0.24. The prescriptive U-factor is 0.30 in all climate zones.
Higher SHGC Fenestration: Increase solar heat gain coefficient (SHGC) to 0.50 in climate zones where heating loads dominate (1, 3, 5 and 16). The baseline SHGC applied in the Standard Design is 0.35 in these climate zones.
Cool Roof: Install a roofing product that’s rated by the Cool Roof Rating Council to have an aged solar reflectance (ASR) equal to or greater than 0.25. Steep-sloped roofs were assumed in all cases. The prescriptive ASR is 0.20 for Climate Zones 10 through 15.
Increased Ceiling Insulation: Increase ceiling level insulation in a vented attic to R-38, R-49, or R-60 insulation.
Slab Insulation: Install R-10 perimeter slab insulation at a depth of 16-inches. This measure doesn’t apply to Climate Zone 16 where slab insulation is required prescriptively.
Low Pressure Drop Ducts: Upgrade the duct distribution system to reduce external static pressure and meet a maximum fan efficacy of 0.35 Watts per cfm (compared to the prescriptively required 0.45 W/cfm). This may involve upsizing ductwork, reducing the total effective length of ducts, and/or selecting low pressure drop components such as filters. Fan watt draw must be verified by a HERS rater according to the procedures outlined in the 2022 Reference Appendices RA3.3 (California Energy Commission, 2021b). This applies to the single family prototype only.
Buried Radial Duct Design: Bury all ductwork in ceiling insulation by laying the ducts across the ceiling joists or inbetween ceiling joists directly on the ceiling drywall. Duct design is based on a radial design where individual ducts are run to each supply register. This allows for smaller diameter ducts, reducing duct losses and more easily meeting fully or deeply buried conditions.13 Duct burial and duct system design must be verified by a HERS rater according to the procedures outlined in the 2022 Reference Appendices RA3.1.4.1.5 and RA3.1.4.1.6 (California Energy Commission, 2021b). This applies to the single family prototype only.
Ductless Mini-Split Heat Pump: In the ADU prototype install a ductless mini-split heat pump with three indoor heads.
The system is evaluated as meeting the criteria for the variable capacity heat pump (VCHP) credit, introduced in the 2019 code cycle, which must be verified by a HERS rater according to the procedures outlined in the 2022 Reference Appendices RA3.4.4.3 (California Energy Commission, 2021b). This credit requires verification of refrigerant charge, that all equipment is entirely within conditioned space, that airflow is directly supplied to all habitable space, and that wall mounted thermostats serve any zones greater than 150 square feet. This measure is non-preempted because it does not require the installation of equipment with efficiencies above federal minimum requirements.
Compact Hot Water Distribution: Design the hot water distribution system to meet minimum requirements for the basic compact hot water distribution credit according to the procedures outlined in the 2022 Reference Appendices RA4.4.6 (California Energy Commission, 2021b). In many single family homes this may require moving the water heater from an exterior to an interior garage wall. CBECC-Res software assumes a 30% reduction in distribution losses for the basic credit. This is prescriptively required in Climate Zones 1 and 16 only.
Solar PV: Installation of on-site PV is required in the 2022 residential code unless an exception is met. The PV sizing methodology in each package was developed to offset annual building electricity use and avoid oversizing. In all cases, 12 Whole house leakage tested at a pressure difference of 50 Pascals between indoors and outdoors. 13 The duct systems in the Central Valley Research Homes Project Final Project Report are illustrative of this approach (Proctor, Wilcox, & Chitwood, 2018).
Cost-Effectiveness Analysis: Single Family New Construction Prototypes, Measure Packages, and Costs
14 California Energy Codes & Standards | A statewide utility program 2024-04-26 PV is evaluated in CBECC-Res according to the California Flexible Installation (CFI) 1 assumptions. To meet CFI eligibility, the requirements of 2022 Reference Appendices JA11.2.2 (California Energy Commission, 2021b) must be met.
The Reach Codes Team used two options within the CBECC-Res software for sizing the PV system. The first option, “Standard Design PV”, was applied in the base case simulations and packages where the PV system size was not changed from the minimum system size required14. For the PV packages, the second option, “Specify PV System Scaling”, was used. In these cases, a scaling of 100 was applied, indicating that the PV system be sized to offset 100% of the estimated electricity use of the Proposed Design case.
One exception to the PV requirement is when the minimum PV system size required is less than 1.8 kW. This exception applies to the ADU models in Climate Zones 1-9, 12, 14, and 16. For these cases no PV system is required by code and no PV system was modeled in the base case simulations.
Battery Energy Storage: A 10 kWh battery system was evaluated in CBECC-Res with control type set to “Basic” and with default efficiencies of 95% for both charging and discharging. 10kWh battery capacity is representative of systems installed in single family homes based on the Self-Generation Incentive Program (SGIP) participant data. The “Basic” control option charges the battery system anytime PV generation is greater than the house load and discharges the battery whenever the house load exceeds PV generation. The battery does not discharge to the grid, maximizing onsite utilization of the PV system and in turn utility bill benefits under NBT. To qualify for the battery storage compliance credit the battery system must meet the requirements outlined in the 2022 Reference Appendices JA12 (California Energy Commission, 2021b). Batteries are not prescriptively required in any climate zone.
Table 5: Incremental Cost Assumptions: Efficiency, PV, and Battery Measures Measure
Performance
Level
Incremental
Cost
(2023 PV$)1
Source & Notes
Single
Family ADU
Reduced
Infiltration
3.0 vs 5.0
ACH50 $591 $362 $0.115/ft2 based on NREL’s BEopt cost database plus $250 HERS rater verification.
Window Ufactor 0.24 vs 0.30 $2,280 $285 $4.23/ft2 window area based on analysis conducted for the 2019 and 2022 Title 24 cycles (Statewide CASE Team, 2018).
Window
SHGC 0.50 vs 0.35 $0 $0
Based on feedback from Statewide CASE Team that higher SHGC does not necessarily have any incremental cost (Statewide CASE Team, 2017).
Cool Roof
0.25 vs 0.20
aged solar
reflectance
$219 $53
$0.07per ft2 of roof area first incremental cost for asphalt shingle product based on the 2022 Nonresidential High Performance Envelope CASE Report (Statewide CASE Team, 2020a). Total costs assume present value of replacement at year 20 and residual cost for remaining product life at end of 30-year analysis period. Higher reflectance values for lower cost are achievable for tile roof products
Attic
Insulation
R-49 vs R-30 $872 n/a
Based on costs from the 2022 Residential Additions & Alterations CASE Report (Statewide CASE Team, 2020b).
R-60 vs R-30 $1,420 n/a
R-60 vs R-38 $1,096 n/a
Slab Edge
Insulation R-10 vs R-0 $651 $449 $4 per linear foot of slab perimeter based on internet research. Assumes 16in depth. 14 The Standard Design PV system is sized to offset the electricity use of the building loads which are typically electric in a mixed fuel home, which includes all loads except space heating, water heating, clothes drying, and cooking.
Cost-Effectiveness Analysis: Single Family New Construction Prototypes, Measure Packages, and Costs
15 California Energy Codes & Standards | A statewide utility program 2024-04-26 Measure
Performance
Level
Incremental
Cost
(2023 PV$)1
Source & Notes
Single
Family ADU
Low
Pressure
Drop Ducts
0.35 vs 0.45
W/cfm $99 n/a
Costs assume one-hour labor for single family and half-hour for the ADU. Labor rate of $88 per hour is from 2022 RS Means for sheet metal workers and includes a weighted average City Cost Index for labor for California.
Buried
Ducts
Buried, radial
design $281 n/a
No cost for laying ducts on attic floor versus suspending, in some cases there will be cost savings. Neutral cost for radiant design versus trunk and branch design. A $250 HERS Rater verification fee is included.
Duct
Insulation R-8 vs R-6 $201 n/a Based on costs from the 2022 Residential Additions & Alterations CASE Report (Statewide CASE Team, 2020b).
Ductless
Mini-Split
Heat Pump
Ductless
system
meeting the
VCHP credit
vs. ducted
split heat
pump
n/a $1,571
Costs were developed based on data from E3’s 2019 report Residential Building Electrification in California (Energy & Environmental Economics, 2019) and the 2022 All-Electric Multifamily CASE Report (Statewide CASE Team, 2020c).
Equipment costs are from the CASE Report for the 10-story multifamily prototype assuming similar sized equipment between the multifamily dwelling unit and the ADU. Thermostat, wiring, electrical, and ducting costs are from the E3 study. A $250 HERS Rater verification fee is also included. Where this measure is applied to the mixed fuel home with a gas furnace, this cost is in addition to the cost difference for a heat pump versus a gas furnace/split AC reported in Section 3.3.2.
Compact
Hot Water
Distribution
Basic credit –
homes with
gas tankless
$196 $0
For single family homes with a gas tankless water heater (mixed fuel homes in Climate Zones 3, 4, 13, 14) assumes adding 20-feet venting at $14.69 per linear foot to locate water heater on interior garage wall, less 20-feet savings for PEX and pipe insulation at $5.98 per linear foot. Costs obtained from online retailers. For single family homes with a HPWH there is an incremental cost savings from less pipe being required. For the ADU it is assumed the credit can be met without any changes to design and there is no cost impact.
Basic credit –
homes with
HPWH
-$134 $0
PV System
First Cost $3.11/
W
$3.11/
W
First costs are from LBNL’s Tracking the Sun 2022 (Barbose, Galen; Darghouth, Naim; O'Shaughnessy, Eric; Forrester, Sydney, 2022) and represent median costs in California in 2022 of $3.78/WDC for residential systems. The first cost was reduced by the solar energy Investment Tax Credit of 30%.2
Inverter replacement cost of $0.14/WDC present value includes replacements at year 11 at $0.15/WDC (nominal) and at year 21 at $0.12/WDC (nominal) per the 2019 PV CASE Report (California Energy Commission, 2017).
System maintenance costs of $0.31/WDC present value assume $0.02/WDC (nominal) annually per the 2019 PV CASE Report (California Energy Commission, 2017).
Inverter
replacement
$0.14/
W
$0.14/
W
Maintenance $0.31/
W
$0.31/
W
Replacement
cost
$648/
kWh
$648/
kWh
Cost-Effectiveness Analysis: Single Family New Construction Prototypes, Measure Packages, and Costs
16 California Energy Codes & Standards | A statewide utility program 2024-04-26 Measure
Performance
Level
Incremental
Cost
(2023 PV$)1
Source & Notes
Single
Family ADU
Battery (10
kWh) First cost $782/kWh
$782/
kWh
First costs of $1,101/kWh are from SGIP residential participant cost data for single family projects between 2020 and 2023. The first cost is reduced by 30% due to the Investment Tax Credit2 and also by $0.15/Wh due to the base SGIP incentive3. The SGIP incentive is only accounted for in IOU territories and not for SMUD and CPAU analyses.
Replacement cost at years 10 and 20 was calculated based on the first cost reduced by 7% annually over the next 10 years for a future value cost of $533/kWh. The 7% reduction is based on SDG&E’s Behind-the-Meter Battery Market Study (E-Source companies, 2020). For projects constructed in 2024 or 2025, the first replacement at year 10 would occur in 2034 or 2035. This replacement cost includes an average Investment Tax Credit of 22% in 2034 and 0% in 20352.
1All first costs are assumed to be financed in a mortgage and interest costs due to financing are included in the incremental costs. See Section 2.1.2 for details. Interest costs were not included for calculating TDV costeffectiveness. 2As part of the Inflation Reduction Act in August 2022 the Section 25D Investment Tax Credit was extended and raised to 30% through 2032 with a step-down beginning in 2033. https://www.seia.org/sites/default/files/2022- 08/Inflation%20Reduction%20Act%20Summary%20PDF%20FINAL.pdf 3SGIP incentives vary by ‘steps’ which reflect utility-specific funding across program implementation years. See:
https://www.selfgenca.com/home/program_metrics/
Cost-Effectiveness Analysis: Single Family New Construction Prototypes, Measure Packages, and Costs
17 California Energy Codes & Standards | A statewide utility program 2024-04-26
3.3.2 Electrification
This analysis compared a code compliant mixed fuel prototype, which uses natural gas for three appliances (cooking, clothes drying and either space heating or water heating), with a code compliant all-electric prototype. The associated costs included the relative costs between natural gas and electric appliances, differences between in-house electricity and natural gas infrastructure, and the associated infrastructure costs for providing natural gas to the building. To estimate costs the Reach Codes Team leveraged costs from the 2019 reach code cost-effectiveness studies for residential new construction (Statewide Reach Codes Team, 2019) and detached accessory dwelling units (Statewide Reach Codes Team, 2021b), 2022 RS Means, PG&E data, published utility schedules and rules, and online research.
3.3.2.1 Utility Infrastructure
This section addresses utility infrastructure costs during construction; appliance-specific infrastructure costs are addressed in Section 0. Table 6 presents total costs for natural gas infrastructure for a single family building within CA gas IOU territory, including distribution and service line extensions, meter installation, and plan review. These costs are applied as cost savings for an all-electric home when compared to a mixed fuel home. This is the component with the highest degree of variability for all-electric homes, as they are project-dependent and may be significantly impacted by such factors as utility territory, site characteristics, distance to the nearest natural gas main and main location, joint trenching, whether work is conducted by the utility or a private contractor, and number of dwelling units per development. All gas utilities participating in this study were solicited for cost information. The CA IOU costs for single family homes presented are based on cost data provided by PG&E.
Extension of service lines from a main distribution line to the home were provided separately for a new subdivision in an undeveloped area ($1,300) as well as an infill development ($6,750). The service extension is typically more costly in an infill scenario due to the disruption of existing roads, sidewalks, and other structures. For this analysis an average of the new subdivision and infill development costs was used, representing 80 percent of the new subdivision and 20 percent infill. In the case of distribution line extensions, the estimated cost is for new greenfield development.
For the single family analysis, based on the Reach Codes Team's conversations with the industry it is assumed that no upgrades to the electrical panel are required and that a 200 Amp panel is typically installed for both mixed fuel and allelectric homes.
Table 6: Single Family IOU Total Natural Gas Infrastructure Costs Item Cost
Distribution Line Extension $1,020
Service Line Extension $2,390
Meter $300
Plan Review Costs $850
Total $4,560
CPAU provides gas service to its customers and therefore separate costs were evaluated based on CPAU gas service connection fees.15 Table 7 presents the breakdown of gas infrastructure costs used in this analysis for CPAU. There is no main distribution line component since Palo Alto has little greenfield space remaining and most of the development is infill.
15 CPAU Schedule G-5 effective 09-01-2019: https://www.cityofpaloalto.org/files/assets/public/utilities/utilities-engineering/generalspecifications/gas-service-connection-fees.pdf Cost-Effectiveness Analysis: Single Family New Construction Prototypes, Measure Packages, and Costs
18 California Energy Codes & Standards | A statewide utility program 2024-04-26 Table 7: Single Family CPAU Total Natural Gas Infrastructure Costs Item Cost
Service Extension $5,892
Meter $1,012
Plan Review Costs $924
Total $7,828
Electricity infrastructure costs for single family homes were not estimated as part of this work as they are expected to be the same for both all-electric and mixed fuel construction. This will change in July 2024 based on the CPUC’s recent decision to eliminate electric line extension subsidies for new construction projects that use natural gas and/or propane.16 This will increase the utility infrastructure costs for mixed fuel homes, relative to all-electric homes, improving the cost-effectiveness of all-electric construction. The Reach Codes Team intends to quantify this impact in future studies.
Table 8 presents utility infrastructure costs for the detached ADU, both mixed fuel and all-electric designs. These costs are directly from the 2019 detached ADU reach code report (Statewide Reach Codes Team, 2021b) and were obtained from stakeholder interviews and RS Means. For the ADU scenario it’s assumed that natural gas infrastructure already exists on the lot and is being extended to the location of the ADU typically at the back of the lot. There are incremental cost savings for an all-electric ADU from not extending the natural gas service; however, there is also a small incremental cost for upgrading the electric service to accommodate the additional electrical load. The Reach Codes Team found that a new detached ADU would require that the building owner upgrade the service connection to the lot in both the mixed fuel ADU design and the all-electric design. The most common size for this upgrade is to upsize the existing panel to 225A, which would not represent an incremental cost from the mixed fuel project to the all-electric project. Feeder wiring to the ADU and the ADU subpanel, on the other hand, will need to be slightly upgraded for the all-electric design.
Table 8: ADU Utility Infrastructure Total and Incremental Costs Mixed Fuel Measure Mixed Fuel
Total Cost All-Electric Measure All-Electric Total Cost All-Electric
Incremental Cost
Site natural gas service
extension $1,998 No site natural gas service $0 ($1,998) Site electrical service
connection upgrade 225A $3,500
Site electrical service
connection upgrade 225A $3,500 $0
100A feeder to ADU with
breaker $933
125A feeder to ADU with
breaker $1,206 $273
100A ADU subpanel $733 125A ADU subpanel $946 $213
Totals $7,164 $5,652 ($1,512)
3.3.2.2 Equipment
This section provides descriptions and costs of the equipment applied to electrify mixed fuel homes in the all-electric packages. The equipment meets but does not exceed federal efficiency requirements to avoid federal preemption concerns.
16 https://www.cpuc.ca.gov/news-and-updates/all-news/cpuc-eliminates-last-remaining-utility-subsidies-for-new-construction-ofbuildings-using-gas-2023 Cost-Effectiveness Analysis: Single Family New Construction Prototypes, Measure Packages, and Costs
19 California Energy Codes & Standards | A statewide utility program 2024-04-26 For the water heating and space conditioning equipment analyzed, cost analyses incorporated the equipment’s effective useful lifetime (EUL), which are summarized in Table 9. The EUL for the heat pump, furnace, and air conditioner are based on the Database for Energy Efficient Resources (DEER) (California Public Utilities Commission, 2021b). Water heating equipment lifetimes are based on DOE’s recent water heater rulemaking (Department of Energy, 2022). Replacement costs are applied when equipment reaches its EUL within the 30-year evaluation period, and in such cases are included in the total lifetime costs. Residual value of the gas furnace and gas tankless at the end of the 30-year analysis period was accounted for to represent the remaining life of the equipment.
In this analysis, replacement costs assume a like-for-like replacement of equipment type and fuel (as listed in Table 9).
However, this may be precluded in the future due to efforts to prohibit the sale of gas equipment currently being considered or undertaken by air districts (ex. BAAQMD, SCAQMD) and the California Air Resources Board (ex. zero NOx appliance rules).
Table 9: Effective Useful Lifetime (EUL) of Water Heating & Space Conditioning Equipment Measure EUL (Years)
Gas Furnace 20
Air Conditioner 15
Heat Pump 15
Gas Tankless Water Heater 20
Heat Pump Water Heater 15
Space Conditioning: This measure covers replacing a prescriptive air conditioner and gas furnace with a minimum efficiency heat pump in applicable climate zones (1, 2, 5 to 12, 15 and 16; see Table 3). Typical incremental costs for this equipment were based on contractor feedback and price variation by system capacity from the AC Wholesalers website and the RS Means cost database (RSMeans, 2022). Costs were applied based on the system capacity from heating and cooling load calculations in CBECC-Res as presented in Table 10. Air conditioner nominal capacity was calculated as the CBECC-Res cooling load, rounded up to the nearest half ton. Heat pump nominal capacity was calculated as the maximum of either the CBECC-Res heating or cooling load, rounded up to the nearest half ton. In both cases a minimum capacity of 1.5-ton was applied as this represents the typical smallest available split system heat pump equipment. Load calculations demonstrated that Climate Zones 2, 5 to 12, and 15 were cooling-dominated while Climate Zones 1 and 16 were heating-dominated. In the heating dominated climate zones the heat pump for the single family home needs to be upsized relative to an air conditioner that only provides cooling.
Replacement costs were estimated based on a contractor survey conducted by the Statewide Reach Codes Team in 2023 (Statewide Reach Codes Team, tbd), less any gas and electric infrastructure costs, and the equipment lifetimes listed in Table 9. Resultant incremental costs are presented in Table 11.
This measure, and thus the incremental cost, does not apply to climate zones where heat pump space conditioning is already prescriptively required (Climate Zones 3, 4, 13, and 14).
Cost-Effectiveness Analysis: Single Family New Construction Prototypes, Measure Packages, and Costs
20 California Energy Codes & Standards | A statewide utility program 2024-04-26 Table 10: Space Conditioning System Nominal Capacities
Climate
Zone
Single Family ADU
Air Conditioner
Capacity (tons)
Heat Pump
Capacity (tons)
Air Conditioner
Capacity (tons)
Heat Pump
Capacity (tons)
1 1.5 2.5 1.5 1.5
2 3 3 1.5 1.5
3 - - - -
4 - - - -
5 3 3 1.5 1.5
6 3 3 1.5 1.5
7 3 3 1.5 1.5
8 2.5 2.5 1.5 1.5
9 2.5 2.5 1.5 1.5
10 2.5 2.5 1.5 1.5
11 3 3 1.5 1.5
12 2.5 2.5 1.5 1.5
13 - - - -
14 - - - -
15 4 4 1.5 1.5
16 2 3.5 1.5 1.5
Table 11: Space Conditioning System Incremental Costs (2023 PV$) Climate
Zone
Single Family ADU
First
Cost
Total Lifetime
Cost (Financed)
First
Cost
Total Lifetime
Cost (Financed)
1 $803 $2,705 ($2,120) ($1,717)
2 ($1,044) ($44) ($2,120) ($1,717)
3 - - - -
4 - - - -
5 ($1,044) ($44) ($2,120) ($1,717)
6 ($1,044) ($44) ($2,120) ($1,717)
7 ($1,044) ($44) ($2,120) ($1,717)
8 ($1,445) ($673) ($2,120) ($1,717)
9 ($1,445) ($673) ($2,120) ($1,717)
10 ($1,445) ($673) ($2,120) ($1,717)
11 ($1,044) ($44) ($2,120) ($1,717)
12 ($1,445) ($673) ($2,120) ($1,717)
13 - - - -
14 - - - -
15 ($1,032) $368 ($2,120) ($1,717)
16 $2,331 $5,123 ($2,120) ($1,717)
Cost-Effectiveness Analysis: Single Family New Construction Prototypes, Measure Packages, and Costs
21 California Energy Codes & Standards | A statewide utility program 2024-04-26 Water Heater: This measure covers replacing a prescriptive gas tankless water heater with a minimum efficiency HPWH in applicable climate zones (3, 4, 13, and 14; see Table 3). Typical incremental costs were based on costs from prior reach code work and recent contractor feedback. Incremental first costs assume a 65-gal HPWH and incremental replacement costs account for equipment lifetimes listed in Table 9. Replacement costs assume no change in cost from the first cost estimates before accounting for inflation, less any gas and electric infrastructure costs. For the ADU analysis the water heater is evaluated within the conditioned space with the supply air ducted from the outside and exhaust air ducted to the outside. A mechanical contractor provided a cost estimate of $943 for ducting through the attic in an ADU where the water heater is in an interior room. This cost is included in the equipment and installation total for the ADU. Resultant incremental costs are presented in Table 12.
Table 12: Heat Pump Water Heating System Incremental Costs (2023 PV$) Item
ADU Single Family
First
Cost
Total Lifetime
Cost
(Financed)
First
Cost
Total Lifetime
Cost
(Financed)
Equipment & Installation $2,243 $3,930 $1,300 $2,267
Electric Service Upgrade $43 $48 $45 $51
In-House Gas Piping ($580) ($651) ($580) ($651)
Total $1,706 $3,327 $765 $1,666
For this electrification analysis, a HPWH that just meets the federal minimum efficiency standards17 of close to 2.0 Uniform Energy Factor (UEF) was evaluated in order to satisfy preemption requirements. However, the Reach Codes Team is not aware of any 2.0 UEF products that are available on the market. The Northwest Energy Efficiency Alliance (NEEA) established its own rating system for high efficiency HPWHs18 and maintains a database of qualified products.
The lowest UEF currently reported in the database is 2.73. In fact, of the four rating tiers offered by NEEA, those meeting Tier 3 or Tier 4 are the dominant products on the market today. According to NEEA all major HPWH manufacturers are represented in NEEA’s qualified product list19 and there are fewer than 10 integrated products certified as Tier 1 or Tier 2, all of which have UEFs greater than 3.0.20 NEEA Tier 3 water heaters were included in the high-efficiency measure packages (see Section 3.4).
Clothes Dryer and Range: After review of various sources, the Reach Codes Team concluded that the cost difference between gas and electric resistance equipment for clothes dryers and stoves is negligible and that the lifetimes of the two technologies are similar. Resultant incremental costs are presented in Table 13. Note that while induction stoves may be a more likely installation option in many homes, CBECC-Res does not currently differentiate between electric technologies for stoves and therefore they were not considered in this analysis. Relative to electric resistance, induction stoves use less energy and improve performance and user satisfaction, at an additional cost.
Electric Service Upgrade (appliance-specific): The 2022 Title 24 Code requires electric readiness for gas appliances; as a result, the incremental costs to provide electrical service for electric appliances are minimal. The incremental costs accounted for in this study — shown in Table 13 — are calculated as the cost to install 220V service for the electric appliances less the cost for the electric ready requirements and for installing 110V service for the 17 The Department of Energy establishes minimum energy conservation standards for consumer products, as directed in the Energy Policy and Conservation Act. See https://www.ecfr.gov/current/title-10/chapter-II/subchapter-D/part-430/subpart-C/section430.32. 18 Based on operational challenges experienced in the past, NEEA established rating test criteria to ensure newly installed HPWHs perform adequately, especially in colder climates. The NEEA rating requires products comply with ENERGY STAR and includes requirements regarding noise and prioritizing heat pump use over supplemental electric resistance heating. 19 https://neea.org/success-stories/heat-pump-water-heaters 20 As of 3/8/2024: https://neea.org/img/documents/residential-unitary-HPWH-qualified-products-list.pdf Cost-Effectiveness Analysis: Single Family New Construction Prototypes, Measure Packages, and Costs
22 California Energy Codes & Standards | A statewide utility program 2024-04-26 comparable gas appliance. Incremental costs are applied for the space conditioner, water heater, and cooking range.
Based on builder surveys, it’s assumed that in a typical mixed fuel home both electric and gas service are provided to the dryer location and therefore no incremental costs for the dryer were applied. Costs assume 50A service for the range and 30A service for the space conditioner and water heater. Costs are assumed to be the same for the single family and ADU analyses.
In-House Natural Gas Infrastructure (from meter to appliances): Installation cost to run a natural gas line from the meter to the appliance location was estimated at $580 per appliance, as shown in Table 13. These costs were based on material costs from Home Depot and labor costs from 2022 RS Means. The material costs were about 1/3 higher in RS Means than Home Depot, so the Reach Codes Team used the lower costs from Home Depot. The Reach Codes Team conducted a pipe sizing analysis for the two single family and one ADU prototype homes to estimate the length and diameter of gas piping required assuming the home included a gas furnace, gas tankless water heater, gas range, and gas dryer. Total estimated costs were very similar for each of the three prototypes and an average cost per appliance of $580 was determined. Costs are assumed to be the same for the single family and ADU analyses.
Table 13: Single Family All-Electric Appliance Incremental Costs Item
ADU & Single Family
First
Cost
Total Lifetime Cost
(Financed)
Electric Resistance vs Gas Cooking
Equipment & Installation $0 $0
Electric Service Upgrade $100 $113
In-House Gas Piping ($580) ($651)
Total ($480) ($539)
Electric Resistance vs Gas Clothes Drying
Equipment & Installation $0 $0
Electric Service Upgrade $0 $0
In-House Gas Piping ($580) ($651)
Total ($580) ($651)
3.4 Measure Packages
The Reach Codes Team evaluated two packages for mixed fuel homes and five packages for all-electric homes for each prototype and climate zone, as described below.
1. All-Electric Code Minimum: This package applied the prescriptive requirements of the 2022 Title 24 Code and replaced gas equipment with minimum efficiency electric equipment.
2. Efficiency Only, all-electric: This package used only efficiency measures that don’t trigger federal preemption issues including envelope, water heating distribution, and duct distribution efficiency measures. For ADUs, this also included ductless variable capacity heat pumps (VCHPs). This package was evaluated for the all-electric homes only.
3. Efficiency + High Efficiency (Preempted) Equipment, all-electric and mixed fuel: This package builds off the Efficiency Only package, adding water heating and space conditioning equipment that is more efficient than federal standards. The Reach Codes Team considers this more reflective of how builders meet above code requirements in practice. This package was evaluated to compare compliance results against the other nonpreempted packages (see Table 27 and Table 28), however cost-effectiveness was not evaluated for this package since it cannot serve as the basis for adoption of a local ordinance. Specifically, it applied:
a. Water heating, all-electric: Heat pump water heaters with a NEEA Tier 3 rating (3.45 UEF). b. Water heating, mixed fuel: High efficiency (0.95 UEF) gas tankless.
Cost-Effectiveness Analysis: Single Family New Construction Prototypes, Measure Packages, and Costs
23 California Energy Codes & Standards | A statewide utility program 2024-04-26 c. Space conditioning, single family: High efficiency (16 SEER2/8 HSPF2) heat pumps. In mixed fuel packages, for climate zones with prescriptive gas heating, high efficiency (16 SEER2/95 AFUE) units were applied.
4. Efficiency + PV, all-electric: This package also builds on the Efficiency Only package, excluding preempted equipment. Instead, PV capacity was added to offset all of the estimated annual electricity use. This package was evaluated for the all-electric homes only.
5. Efficiency + PV + Battery, all-electric and mixed fuel: Using the Efficiency + PV package as a starting point for the all-electric analysis, a battery system was added. For mixed fuel homes the package of efficiency measures differed from the all-electric homes in some climate zones to arrive at a cost-effective solution.
To reiterate previous statements, the non-preempted measures used in all of the above packages (except for the AllElectric Code Minimum package) are referred to as “Efficiency measures”. As noted above, these measures may differ by prototype (single family vs. ADU) and by package. See Table 40 and Table 41 for the details of these measures.
Cost-Effectiveness Analysis: Single Family New Construction Results
24 California Energy Codes & Standards | A statewide utility program 2024-04-26 4 Results
Section 4.1 presents compliance results for all-electric versus mixed fuel code minimum packages to provide a broad overview of how these different approaches impact code compliance. Sections 4.2 to 4.5 present EDR results along with other savings data for packages of particular interest, as well as cost-effectiveness results for all packages.
Section 4.5 presents results for sensitivity analyses. All results reflect savings over a 30-year analysis period and are compared against the 2022 prescriptive baseline.
4.1 Compliance Results: All-Electric vs. Mixed Fuel Code Minimum The Reach Codes Team evaluated the compliance impacts of a prescriptive all-electric home as well as a traditional mixed fuel home with four gas appliances (space heating, water heating, cooking, clothes drying). Compliance is relative to the 2022 prescriptive base case home with three gas appliances which, by definition, has a compliance margin of zero in all climate zones. The impacts for the all-electric single family home and the ADU are presented in Figure 1 and Figure 2, respectively. The all-electric single family and ADU home prototypes are code compliant with both EDR1 (source energy) and efficiency EDR2 (TDV energy) in all climate zones, though the compliance margin is highly variable across climate zones. The four gas appliance single family home is presented in Figure 3. This case is not code compliant in any climate zone.
Figure 1: Single family all-electric home compliance impacts. 0 5
10 15
20 25
30 CZ01 CZ02 CZ03 CZ04 CZ05 CZ06 CZ07 CZ08 CZ09 CZ10 CZ11 CZ12 CZ13 CZ14 CZ15 CZ16 EDR Margin
All-Electric Prescrip�ve
Source (EDR1) TDV (EDR2 Efficiency)
Cost-Effectiveness Analysis: Single Family New Construction Results
25 California Energy Codes & Standards | A statewide utility program 2024-04-26 Figure 2: ADU all-electric home compliance impacts.
Figure 3: Single family four gas appliance home compliance impacts.
This analysis illustrates a couple of interesting points:
1. The 2022 compliance metrics are important drivers encouraging electrification. The compliance penalties associated with the four gas appliance home scenarios are significant and will require deep efficiency measures to overcome.
2. The 2022 Title 24 Code’s new source energy metric combined with the heat pump baseline encourage allelectric construction, providing a compliance benefit that allows for some amount of prescriptively required building efficiency to be traded off and still comply when using the performance method. 0 2
4 6
8 10
12 14
CZ01 CZ02 CZ03 CZ04 CZ05 CZ06 CZ07 CZ08 CZ09 CZ10 CZ11 CZ12 CZ13 CZ14 CZ15 CZ16 EDR Margin
All-Electric Prescrip�ve
Source (EDR1) TDV (EDR2 Efficiency)
-18
-16
-14
-12
-10
-8
-6
-4
-2
0 2
CZ01 CZ02 CZ03 CZ04 CZ05 CZ06 CZ07 CZ08 CZ09 CZ10 CZ11 CZ12 CZ13 CZ14 CZ15 CZ16 EDR Margin
Mixed Fuel Prescrip�ve, 4 Gas Appliances
Source (EDR1) TDV (EDR2 Efficiency)
Cost-Effectiveness Analysis: Single Family New Construction 26 Results
California Energy Codes & Standards | A statewide utility program 2024-04-26
4.2 All-Electric Code Minimum Results
Table 14 shows results for the single family all-electric Code Minimum measure package. Utility cost savings are negative, indicating an increase in utility costs for the all-electric building, everywhere except in CPAU and SMUD territories. In all cases the incremental cost is negative, which reflects cost savings for the all-electric building due to elimination of gas infrastructure costs. The package is cost-effective based on TDV in all cases but one (Climate Zone 16); it’s not cost-effective On-Bill in Climate Zones 1, 3, 14, and 16.
Table 15 shows the all-electric Code Minimum package results for the ADU. Utility savings and incremental costs reflect the same general trend as single family homes. Cost-effectiveness is less favorable than the single family application, with TDV cost-effectiveness not met in Climate Zones 3, 4, 13, and 14, and On-Bill cost-effectiveness met only in Climate Zones 4 in CPAU territory, 10 in SCE/SCG territory, 12 in SMUD/PG&E territory, 11 and 15. Costeffectiveness in Climate Zones 3, 4, 13, and 14 is worse than in the other climate zones due to the higher cost of converting from a gas tankless to a ducted HPWH (see Table 3) which isn’t offset enough by the energy savings. Cost savings due to elimination of gas infrastructure costs are also lower for the ADU relative to the single family home.
Cost-Effectiveness Analysis: Single Family New Construction 27 Results
California Energy Codes & Standards | A statewide utility program 2024-04-26 Table 14: Single Family Cost-Effectiveness: All-Electric Code Minimum 1 Though uncommon, incremental costs can be negative, reflecting initial construction cost savings. When paired with increased energy costs (negative benefits), the construction cost savings are treated as the ‘benefit’ while the increased energy costs are the ‘cost,’ which may yield positive cost effectiveness. See Section 2.1.2.3 for more information.
Climate
Zone
Electric
/Gas Utility
Total
EDR1
Margin
Efficiency
EDR2
Margin
Annual
Elec
Savings
(kWh)
Annual
Gas
Savings
(therms)
Utility Cost Savings Incremental Cost1 On-Bill TDV
First
Year
Lifecycle
(2022$) First Year Lifecycle (2022$)
B/C
Ratio NPV B/C Ratio NPV
CZ01 PGE 25.8 12.4 -4,308 398 ($431) ($3,873) ($4,816) ($3,605) 0.9 ($268) >1 $5,702 CZ02 PGE 14.0 8.3 -2,888 246 ($327) ($4,000) ($6,664) ($6,355) 1.6 $2,355 >1 $7,711 CZ03 PGE 9.1 7.7 -2,433 171 ($303) ($4,734) ($4,854) ($4,644) 0.98 ($90) 25.3 $3,887 CZ04 PGE 8.8 5.0 -2,232 163 ($251) ($3,665) ($4,854) ($4,644) 1.3 $979 >1 $4,494 CZ04 CPAU 8.8 5.0 -2,232 163 ($36) $2,123 ($8,122) ($8,314) >1 $10,437 >1 $7,762 CZ05 PGE 6.5 4.0 -1,960 133 ($292) ($4,981) ($6,664) ($6,355) 1.3 $1,373 6.1 $4,633 CZ05 PGE/SCG 6.5 4.0 -1,960 133 ($277) ($4,532) ($6,664) ($6,355) 1.4 $1,823 6.1 $4,633 CZ06 SCE/SCG 4.2 3.5 -1,432 84 ($231) ($4,015) ($6,664) ($6,355) 1.6 $2,339 4.7 $4,353 CZ07 SDGE 2.8 3.2 -1,293 69 ($266) ($5,731) ($6,664) ($6,355) 1.1 $624 4.2 $4,211 CZ08 SCE/SCG 2.1 1.1 -1,293 67 ($228) ($4,192) ($7,065) ($6,983) 1.7 $2,792 4.2 $4,674 CZ09 SCE 3.6 1.9 -1,453 84 ($237) ($4,153) ($7,065) ($6,983) 1.7 $2,831 5.5 $5,013 CZ10 SCE/SCG 4.8 2.3 -1,683 107 ($258) ($4,342) ($7,065) ($6,983) 1.6 $2,642 7.4 $5,287 CZ10 SDGE 4.8 2.3 -1,683 107 ($265) ($5,158) ($7,065) ($6,983) 1.4 $1,825 7.4 $5,287 CZ11 PGE 11.4 4.9 -2,712 226 ($306) ($3,803) ($6,664) ($6,355) 1.7 $2,552 >1 $7,153 CZ12 PGE 11.5 5.6 -2,554 212 ($294) ($3,773) ($7,065) ($6,983) 1.9 $3,210 >1 $7,504 CZ12 SMUD/PGE 11.5 5.6 -2,554 212 $79 $4,731 ($7,065) ($6,983) >1 $11,714 >1 $7,504 CZ13 PGE 8.3 3.2 -2,095 154 ($224) ($3,164) ($4,854) ($4,644) 1.5 $1,480 >1 $4,490 CZ14 SCE/SCG 8.8 3.3 -2,291 159 ($322) ($5,166) ($4,854) ($4,644) 0.9 ($522) >1 $4,105 CZ14 SDGE 8.8 3.3 -2,291 159 ($344) ($6,361) ($4,854) ($4,644) 0.7 ($1,717) >1 $4,105 CZ15 SCE/SCG 0.9 1.0 -1,167 53 ($217) ($4,152) ($6,652) ($5,942) 1.4 $1,791 3.0 $3,439 CZ16 PG&E 21.3 0.7 -4,729 403 ($548) ($6,581) ($3,289) ($1,187) 0.2 ($5,394) 0.4 ($1,339) Cost-Effectiveness Analysis: Single Family New Construction 28 Results
California Energy Codes & Standards | A statewide utility program 2024-04-26 Table 15: ADU Cost-Effectiveness: All-Electric Code Minimum 1 Though uncommon, incremental costs can be negative, reflecting initial construction cost savings. When paired with increased energy costs (negative benefits), the construction cost savings are treated as the ‘benefit’ while the increased energy costs are the ‘cost,’ which may yield positive cost effectiveness. See Section 2.1.2.3 for more information.
Climate
Zone
Electric
/Gas
Utility
Total
EDR1
Margin
Efficiency
EDR2
Margin
Annual
Elec
Savings
(kWh)
Annual
Gas
Savings
(therms)
Utility Cost Savings Incremental Cost1 On-Bill TDV
First
Year
Lifecycle
(2022$) First Year Lifecycle (2022$)
B/C
Ratio NPV B/C Ratio NPV
CZ01 PGE 11.9 6.1 -1,641 114 ($353) ($6,682) ($4,692) ($4,605) 0.7 ($2,077) 3.9 $2,986 CZ02 PGE 5.7 3.4 -1,245 75 ($312) ($6,347) ($4,692) ($4,605) 0.7 ($1,742) 2.7 $2,515 CZ03 PGE 2.9 2.3 -1,672 123 ($377) ($7,138) ($863) $442 0.0 ($7,581) 0.0 ($1,489) CZ04 PGE 2.4 1.4 -1,612 118 ($366) ($6,964) ($863) $442 0.0 ($7,406) 0.0 ($801) CZ04 CPAU 2.4 1.4 -1,612 118 $25 $3,035 ($863) $442 6.9 $2,592 0.0 ($801) CZ05 PGE 1.8 0.8 -1,026 49 ($302) ($6,517) ($4,692) ($4,605) 0.7 ($1,912) 2.0 $2,021 CZ05 PGE/SCG 1.8 0.8 -1,026 49 ($257) ($5,178) ($4,692) ($4,605) 0.9 ($574) 2.0 $2,021 CZ06 SCE/SCG 0.5 0.2 -904 38 ($243) ($4,923) ($4,692) ($4,605) 0.9 ($318) 2.1 $2,135 CZ07 SDGE 0.1 0.1 -884 37 ($337) ($7,903) ($4,692) ($4,605) 0.6 ($3,298) 2.2 $2,205 CZ08 SCE/SCG 0.1 0.1 -878 36 ($241) ($4,894) ($4,692) ($4,605) 0.9 ($289) 2.3 $2,274 CZ09 SCE 0.4 0.1 -903 38 ($243) ($4,914) ($4,692) ($4,605) 0.9 ($310) 2.4 $2,321 CZ10 SCE/SCG 1.0 0.4 -952 43 ($189) ($3,629) ($4,692) ($4,605) 1.3 $976 2.8 $2,577 CZ10 SDGE 1.0 0.4 -952 43 ($249) ($5,689) ($4,692) ($4,605) 0.8 ($1,084) 2.8 $2,577 CZ11 PGE 4.6 2.1 -1,209 71 ($224) ($4,405) ($4,692) ($4,605) 1.0 $200 3.5 $2,870 CZ12 PGE 4.6 2.3 -1,183 69 ($306) ($6,315) ($4,692) ($4,605) 0.7 ($1,710) 3.0 $2,684 CZ12 SMUD/PGE 4.6 2.3 -1,183 69 ($65) ($808) ($4,692) ($4,605) 5.7 $3,797 3.0 $2,684 CZ13 PGE 3.1 1.3 -1,611 112 ($218) ($3,689) ($863) $442 0.0 ($4,131) 0.0 ($858) CZ14 SCE/SCG 3.5 1.2 -1,714 115 ($375) ($6,933) ($863) $442 0.0 ($7,375) 0.0 ($1,089) CZ14 SDGE 3.5 1.2 -1,714 115 ($483) ($10,348) ($863) $442 0.0 ($10,790) 0.0 ($1,089) CZ15 SCE/SCG 0.0 0.0 -864 36 ($172) ($3,359) ($4,692) ($4,605) 1.4 $1,246 2.6 $2,477 CZ16 PG&E 11.2 0.1 -1,781 122 ($379) ($7,167) ($4,692) ($4,605) 0.6 ($2,562) 2.1 $2,133 Cost-Effectiveness Analysis: Single Family New Construction 29 Results
California Energy Codes & Standards | A statewide utility program 2024-04-26
4.3 All-Electric Efficiency, PV, and Battery Results
Table 16 and Table 17 compare cost-effectiveness results for the all-electric packages for the single family and ADU prototypes, respectively, with the exception of the all-electric Efficiency + High Efficiency (Preempted) Equipment package (cost-effectiveness was not evaluated for this package but see Table 27 and Table 28 for a comparison of compliance impacts). In almost all cases the packages are cost-effective based on TDV. On-Bill cost-effectiveness generally improves with the addition of efficiency measures, further improves with an upsized PV system, and improves even more once batteries are added. A summary of measures included in each package is provided in Appendix 7.3 Summary of Measures by Package. The efficiency measures added to the all-electric package to meet minimum code requirements are described in Table 39 and Table 41.
Table 16: Single Family Cost-Effectiveness: Comparison of All-Electric Efficiency Only, PV, and Battery Packages Climate
Zone
Electric
/Gas Utility
All-Electric Code Minimum All-Electric Efficiency Only All-Electric-Efficiency + PV All-Electric Efficiency + PV + Battery
On-Bill TDV On-Bill TDV On-Bill TDV On-Bill TDV
B/C
Ratio NPV B/C Ratio NPV B/C Ratio NPV B/C Ratio NPV B/C Ratio NPV B/C Ratio NPV B/C Ratio NPV B/C Ratio NPV CZ01 PGE 0.93 ($268) >1 $5,702 >1 $2,945 >1 $8,168 0.9 ($1,313) 1.8 $9,817 1.0 $1,012 1.2 $4,391 CZ02 PGE 1.6 $2,355 >1 $7,711 8.9 $3,870 >1 $9,325 1.5 $2,242 4.2 $12,452 1.3 $4,962 1.5 $8,190 CZ03 PGE 0.98 ($90) 25.3 $3,887 1.1 $168 >1 $3,939 0.8 ($903) 2.8 $6,465 1.1 $2,114 1.1 $1,347 CZ04 PGE 1.3 $979 >1 $4,494 1.7 $1,054 >1 $4,849 1.1 $204 3.5 $7,893 1.2 $3,709 1.3 $4,506 CZ04 CPAU >1 $10,437 >1 $7,762 >1 $10,021 >1 $8,117 >1 $14,776 >1 $11,161 0.9 ($1,076) 1.5 $6,724 CZ05 PGE 1.3 $1,373 6.1 $4,633 1.6 $1,975 >1 $4,985 2.2 $1,457 8.5 $7,927 1.3 $5,551 1.2 $3,296 CZ05 PGE/SCG 1.4 $1,823 6.1 $4,633 1.9 $2,424 >1 $4,985 2.6 $1,907 8.5 $7,927 1.4 $6,001 1.2 $3,296 CZ06 SCE/SCG 1.6 $2,339 4.7 $4,353 1.6 $1,813 >1 $4,119 109.5 $2,638 152.4 $6,727 1.5 $7,153 1.2 $2,276 CZ07 SDGE 1.1 $624 4.2 $4,211 1.2 $839 8.3 $4,070 5.7 $469 >1 $6,079 2.0 $13,798 1.1 $1,186 CZ08 SCE/SCG 1.7 $2,792 4.2 $4,674 1.8 $2,574 17.7 $4,642 >1 $3,329 >1 $7,492 1.7 $8,899 1.2 $2,085 CZ09 SCE 1.7 $2,831 5.5 $5,013 1.9 $2,699 >1 $5,087 >1 $3,634 >1 $8,007 1.7 $9,151 1.3 $3,630 CZ10 SCE/SCG 1.6 $2,642 7.4 $5,287 2.0 $2,668 >1 $5,376 >1 $3,765 >1 $8,347 1.7 $10,088 1.3 $3,901 CZ10 SDGE 1.4 $1,825 7.4 $5,287 1.8 $2,438 >1 $5,376 >1 $2,539 >1 $8,347 2.4 $19,463 1.3 $3,901 CZ11 PGE 1.7 $2,552 >1 $7,153 >1 $4,159 >1 $8,524 1.8 $2,984 4.6 $11,310 1.4 $7,781 1.5 $8,757 CZ12 PGE 1.9 $3,210 >1 $7,504 4.6 $3,742 >1 $8,084 1.9 $2,561 5.5 $11,063 1.3 $6,021 1.5 $8,216 CZ12 SMUD/PGE >1 $11,714 >1 $7,504 >1 $10,665 >1 $8,084 5.8 $13,407 5.5 $11,063 0.9 ($1,237) 1.4 $7,166 CZ13 PGE 1.5 $1,480 >1 $4,490 >1 $2,876 >1 $5,773 1.7 $2,334 3.7 $8,341 1.4 $7,848 1.4 $7,005 CZ14 SCE/SCG 0.9 ($522) >1 $4,105 1.8 $811 >1 $5,461 1.6 $2,558 3.6 $9,965 1.6 $10,569 1.4 $6,204 CZ14 SDGE 0.7 ($1,717) >1 $4,105 1.5 $643 >1 $5,461 1.2 $922 3.6 $9,965 2.1 $20,099 1.4 $6,204 CZ15 SCE/SCG 1.4 $1,791 3.0 $3,439 8.0 $3,267 >1 $4,669 >1 $3,940 >1 $6,120 2.0 $13,576 0.99 ($80) CZ16 PG&E 0.2 ($5,394) 0.4 ($1,339) 0.2 ($1,946) 1.7 $1,894 0.8 ($3,199) 1.6 $6,711 1.0 $206 1.1 $1,690 Cost-Effectiveness Analysis: Single Family New Construction 30 Results
California Energy Codes & Standards | A statewide utility program 2024-04-26 Table 17: ADU Cost-Effectiveness: All-Electric Energy Efficiency + Additional PV + Battery Climate
Zone
Electric
/Gas Utility
All-Electric Code Minimum All-Electric Efficiency Only All-Electric Efficiency + PV All-Electric Efficiency + PV + Battery On-Bill TDV On-Bill TDV On-Bill TDV On-Bill TDV
B/C
Ratio NPV B/C Ratio NPV B/C Ratio NPV B/C Ratio NPV B/C Ratio NPV B/C Ratio NPV B/C Ratio NPV B/C Ratio NPV CZ01 PGE 0.7 ($2,077) 3.9 $2,986 0.6 ($1,727) >1 $2,900 1.2 $2,003 1.5 $5,010 0.997 ($79) 0.9 ($2,884) CZ02 PGE 0.7 ($1,742) 2.7 $2,515 0.5 ($2,541) >1 $1,945 1.4 $3,532 1.8 $6,360 1.1 $1,302 0.98 ($410) CZ03 PGE 0.0 ($7,581) 0.0 ($1,489) 0.0 ($8,981) 0.0 ($2,680) 0.8 ($2,489) 1.1 $1,436 0.8 ($4,949) 0.8 ($5,369) CZ04 PGE 0.0 ($7,406) 0.0 ($801) 0.0 ($8,705) 0.4 ($1,762) 0.9 ($1,480) 1.3 $3,589 0.9 ($3,501) 0.8 ($3,849) CZ04 CPAU 6.9 $2,592 0.0 ($801) 1.3 $944 0.4 ($1,762) 1.7 $8,498 1.3 $3,589 0.7 ($9,161) 0.8 ($4,899) CZ05 PGE 0.7 ($1,912) 2.0 $2,021 0.4 ($3,310) 1.4 $650 1.6 $4,015 1.9 $5,436 1.1 $2,498 0.9 ($1,611) CZ05 PGE/SCG 0.9 ($574) 2.0 $2,021 0.6 ($1,972) 1.4 $650 1.8 $5,353 1.9 $5,436 1.2 $3,836 0.9 ($1,611) CZ06 SCE/SCG 0.9 ($318) 2.1 $2,135 0.6 ($1,579) 2.1 $1,103 2.0 $5,866 2.2 $6,551 1.1 $2,799 0.95 ($852) CZ07 SDGE 0.6 ($3,298) 2.2 $2,205 0.4 ($4,255) 1.8 $941 1.8 $5,667 1.9 $5,493 1.5 $10,358 0.9 ($1,804) CZ08 SCE/SCG 0.9 ($289) 2.3 $2,274 0.6 ($1,432) 2.1 $1,179 2.0 $6,364 2.3 $7,936 1.2 $4,058 0.97 ($609) CZ09 SCE 0.9 ($310) 2.4 $2,321 0.6 ($1,494) 2.3 $1,280 2.0 $6,568 2.4 $7,709 1.2 $4,314 0.99 ($279) CZ10 SCE/SCG 1.3 $976 2.8 $2,577 0.96 ($106) 3.7 $1,593 2.2 $734 6.7 $3,496 0.9 ($860) 0.7 ($3,944) CZ10 SDGE 0.8 ($1,084) 2.8 $2,577 0.6 ($1,787) 3.7 $1,593 0.0 ($1,465) 6.7 $3,496 1.3 $5,079 0.7 ($3,944) CZ11 PGE 1.0 $200 3.5 $2,870 10.7 ($96) >1 $2,531 0.7 ($602) 3.2 $4,037 0.9 ($1,125) 0.9 ($1,893) CZ12 PGE 0.7 ($1,710) 3.0 $2,684 0.5 ($2,538) >1 $1,878 1.6 $4,644 1.9 $6,675 1.1 $2,970 1.0 $178 CZ12 SMUD/PGE 5.7 $3,797 3.0 $2,684 13 $1,980 >1 $1,878 1.7 $5,737 1.9 $6,675 0.6 ($9,432) 0.96 ($872) CZ13 PGE 0.0 ($4,131) 0.0 ($858) 0.0 ($4,502) 0.6 ($1,223) 0.3 ($4,759) 1.1 $305 0.8 ($4,729) 0.7 ($5,491) CZ14 SCE/SCG 0.0 ($7,375) 0.0 ($1,089) 0.0 ($7,929) 0.5 ($1,684) 1.1 $1,555 1.5 $5,935 1.0 $1,222 0.9 ($1,525) CZ14 SDGE 0.0 ($10,790) 0.0 ($1,089) 0.0 ($10,375) 0.5 ($1,684) 1.2 $2,956 1.5 $5,935 1.4 $10,678 0.9 ($1,525) CZ15 SCE/SCG 1.4 $1,246 2.6 $2,477 2.4 $1,243 >1 $2,342 >1 $1,729 >1 $3,560 1.2 $2,631 0.8 ($2,812) CZ16 PG&E 0.6 ($2,562) 2.1 $2,133 0.5 ($2,378) >1 $2,282 1.6 $5,433 2.0 $7,875 1.2 $3,618 1.0 $611 Cost-Effectiveness Analysis: Single Family New Construction 31 Results
California Energy Codes & Standards | A statewide utility program 2024-04-26
4.4 Mixed Fuel Results
Table 18 and Table 19 show results for the mixed fuel Efficiency + PV + Battery package for Single Family and ADU prototypes, respectively. On a TDV basis, this package is cost-effective only in Climate Zone 1 for single family and in no cases for ADUs. However, this package is cost-effective On-Bill for the single family home in all climate zones except 4 in CPAU territory and 12 in SMUD/PG&E territory. On-Bill cost-effectiveness for the ADU home, on the other hand, is seen only in Climate Zones 2, 5, 7 through 9, 10 in SDG&E territory, 12 in PG&E territory, 14, and 16.
Table 18: Single Family Cost-Effectiveness: Mixed Fuel Efficiency + PV + Battery Climate
Zone
Electric
/Gas Utility
Total
EDR1
Margin
Efficiency
EDR2
Margin
Annual
Elec
Savings
(kWh)
Annual
Gas
Savings
(therms)
Utility Cost
Savings Incremental Cost On-Bill TDV
First
Year
Lifecycle
(2022$)
First
Year
Lifecycle
(2022$)
B/C
Ratio NPV B/C Ratio NPV
CZ01 PGE 22.6 18.8 1,571 116 $1,084 $26,667 $11,160 $20,166 1.3 $6,501 1.0 $500 CZ02 PGE 14.1 7.4 1,257 34 $913 $21,353 $10,268 $18,868 1.1 $2,486 0.9 ($1,282) CZ03 PGE 12.8 4.3 858 7 $785 $18,003 $8,708 $16,900 1.1 $1,104 0.7 ($4,777) CZ04 PGE 13.2 4.3 790 6 $803 $18,394 $9,623 $17,938 1.0 $456 0.8 ($3,925) CZ04 CPAU 13.2 4.3 790 6 $123 $2,877 $10,673 $19,172 0.2 ($16,295) 0.7 ($4,975) CZ05 PGE 14.8 4.9 1,178 13 $905 $20,821 $9,441 $17,885 1.2 $2,936 0.8 ($3,468) CZ05 PGE/SCG 14.8 4.9 1,178 13 $900 $20,690 $9,441 $17,885 1.2 $2,805 0.8 ($3,468) CZ06 SCE/SCG 18.3 5.5 888 6 $864 $19,539 $9,266 $17,587 1.1 $1,951 0.8 ($3,941) CZ07 SDGE 18.7 4.8 832 4 $1,134 $27,505 $9,214 $17,537 1.6 $9,967 0.7 ($4,817) CZ08 SCE/SCG 17.1 3.0 777 2 $920 $20,754 $9,134 $17,410 1.2 $3,344 0.7 ($4,341) CZ09 SCE 16.2 3.1 833 3 $922 $20,804 $9,152 $17,435 1.2 $3,369 0.8 ($3,839) CZ10 SCE/SCG 14.4 2.7 846 2 $958 $21,608 $8,489 $16,733 1.3 $4,875 0.7 ($3,859) CZ10 SDGE 14.4 2.7 846 2 $1,288 $31,210 $8,489 $16,733 1.9 $14,477 0.7 ($3,859) CZ11 PGE 12.9 5.1 1,025 26 $1,031 $23,949 $9,828 $18,296 1.3 $5,653 0.94 ($1,066) CZ12 PGE 13.2 4.8 1,098 23 $923 $21,415 $10,065 $18,616 1.2 $2,800 0.93 ($1,194) CZ12 SMUD/PGE 13.2 4.8 1,098 23 $253 $6,133 $11,115 $19,850 0.3 ($13,717) 0.9 ($2,244) CZ13 PGE 12.3 4.2 1,006 5 $1,016 $23,250 $9,831 $18,236 1.3 $5,013 0.9 ($2,354) CZ14 SCE/SCG 13.4 5.4 1,514 6 $1,093 $24,697 $10,741 $19,342 1.3 $5,354 0.9 ($1,910) CZ14 SDGE 13.4 5.4 1,514 6 $1,421 $34,477 $10,741 $19,342 1.8 $15,135 0.9 ($1,910) CZ15 SCE/SCG 13.5 3.8 531 2 $1,140 $25,708 $8,586 $16,630 1.5 $9,078 0.6 ($5,490) CZ16 PG&E 20.4 14.2 1,228 114 $1,070 $26,218 $12,086 $20,964 1.3 $5,254 0.98 ($444) Cost-Effectiveness Analysis: Single Family New Construction 32 Results
California Energy Codes & Standards | A statewide utility program 2024-04-26
Table 19: ADU Cost-Effectiveness: Mixed Fuel Efficiency + PV + Battery Climate
Zone
Electric
/Gas Utility
Total
EDR1
Margin
Efficiency
EDR2
Margin
Annual
Elec
Savings
(kWh)
Annual
Gas
Savings
(therms)
Utility Cost
Savings Incremental Cost On-Bill TDV
First
Year
Lifecycle
(2022$)
First
Year
Lifecycle
(2022$)
B/C
Ratio NPV B/C Ratio NPV
CZ01 PGE 18.5 7.7 3,666 20 $1,078 $24,880 $15,432 $25,919 0.96 ($1,040) 0.7 ($6,719) CZ02 PGE 16.6 3.5 3,472 11 $1,042 $23,928 $13,846 $23,790 1.0 $138 0.8 ($4,128) CZ03 PGE 11.8 1.2 2,679 0 $781 $17,816 $11,879 $21,215 0.8 ($3,399) 0.6 ($6,826) CZ04 PGE 13.3 1.6 2,799 0 $859 $19,588 $12,213 $21,598 0.9 ($2,011) 0.7 ($5,306) CZ04 CPAU 13.3 1.6 2,799 0 $391 $8,911 $13,263 $22,833 0.4 ($13,922) 0.7 ($6,356) CZ05 PGE 16.9 1.1 3,309 2 $1,031 $23,539 $12,668 $22,274 1.1 $1,265 0.8 ($4,765) CZ05 PGE/SCG 16.9 1.1 3,309 2 $1,031 $23,520 $12,668 $22,274 1.1 $1,246 0.8 ($4,765) CZ06 SCE/SCG 19.8 1.2 3,285 1 $953 $21,468 $12,496 $22,043 0.97 ($575) 0.8 ($3,877) CZ07 SDGE 20.3 1.2 3,278 0 $1,296 $31,370 $12,869 $22,545 1.4 $8,825 0.8 ($4,633) CZ08 SCE/SCG 20.4 0.5 3,505 0 $1,040 $23,434 $12,952 $22,678 1.0 $755 0.8 ($3,522) CZ09 SCE 19.6 0.5 3,497 0 $1,030 $23,213 $12,691 $22,327 1.0 $886 0.8 ($3,318) CZ10 SCE/SCG 19.0 0.6 729 0 $537 $12,107 $8,436 $16,606 0.7 ($4,499) 0.5 ($7,344) CZ10 SDGE 19.0 0.6 729 0 $813 $19,671 $8,436 $16,606 1.2 $3,065 0.5 ($7,344) CZ11 PGE 17.6 3.0 871 10 $663 $15,273 $9,218 $17,568 0.9 ($2,295) 0.7 ($5,528) CZ12 PGE 16.7 2.7 3,594 9 $1,112 $25,496 $13,764 $23,710 1.1 $1,786 0.8 ($3,321) CZ12 SMUD/PGE 16.7 2.7 3,594 9 $537 $12,380 $14,844 $24,944 0.5 ($12,564) 0.8 ($4,371) CZ13 PGE 14.5 2.2 273 0 $551 $12,569 $7,979 $15,904 0.8 ($3,335) 0.5 ($6,903) CZ14 SCE/SCG 14.5 3.2 3,499 0 $1,006 $22,671 $12,815 $22,325 1.0 $346 0.8 ($3,423) CZ14 SDGE 14.5 3.2 3,499 0 $1,351 $32,711 $12,815 $22,325 1.5 $10,386 0.8 ($3,423) CZ15 SCE/SCG 19.2 1.8 551 0 $683 $15,387 $8,478 $16,574 0.9 ($1,187) 0.5 ($7,021) CZ16 PG&E 18.3 6.3 3,680 24 $1,117 $25,838 $13,872 $23,801 1.1 $2,037 0.8 ($3,759) Cost-Effectiveness Analysis: Single Family New Construction 33 Results
California Energy Codes & Standards | A statewide utility program 2024-04-26
4.5 Greenhouse Gas Reductions
Table 20 and Table 21 present greenhouse gas reductions for the single family and ADU prototypes, respectively. Savings represent average annual savings over the 30-year lifetime of the analysis. Greenhouse gas reductions are greatest for the all-electric Efficiency + PV + Battery package in all cases. For the single family homes, the all-electric Code Minimum case reduces greenhouse gas emissions as much or greater than the mixed fuel Efficiency + PV + Battery package in Climate Zones 1 through 4, 11 through 13, and 16—showcasing the benefit of all-electric construction over even the most ambitious of mixed fuel construction packages evaluated in this study. The trend differs for the ADU where the mixed fuel Efficiency + PV + Battery package results in more greenhouse gas savings than the all-electric Code Minimum in all climate zones except Climate Zones 3, 4, and 13. In most of the climate zones (1, 2, 5 through 12, 15, and 16) the allelectric ADU involves electrification of space heating, cooking, and clothes drying. The space heating loads for the ADU are very low, even in the colder climates, and as a result the greenhouse gas savings from efficiency measures, PV and battery are greater than just code minimum electrification. This is also the case for single family homes in Climate Zones 5 through 10, and 15 where space heating loads are low.
Table 20: Single Family Greenhouse Gas Reductions (metric tons) Climate
Zone
Single Family All-Electric Single Family Mixed Fuel
Code
Minimum
Efficiency
Only
Efficiency +
High
Efficiency
Equipment
Efficiency +
PV
Efficiency +
PV +
Battery
Efficiency +
High
Efficiency
Equipment
Efficiency +
PV +
Battery
CZ01 1.5 1.7 1.8 1.8 2.3 0.8 1.1
CZ02 0.9 1.0 1.1 1.1 1.6 0.5 0.7
CZ03 0.7 0.7 0.8 0.8 1.3 0.2 0.5
CZ04 0.7 0.7 0.8 0.8 1.3 0.2 0.5
CZ05 0.4 0.5 0.6 0.6 1.1 0.2 0.6
CZ06 0.3 0.3 0.3 0.4 0.9 0.1 0.5
CZ07 0.2 0.2 0.3 0.3 0.8 0.1 0.5
CZ08 0.2 0.2 0.3 0.3 0.8 0.1 0.5
CZ09 0.3 0.3 0.3 0.4 0.9 0.1 0.5
CZ10 0.3 0.4 0.4 0.5 1.0 0.1 0.5
CZ11 0.8 0.9 1.0 1.0 1.5 0.4 0.7
CZ12 0.7 0.8 0.9 0.9 1.4 0.4 0.6
CZ13 0.6 0.7 0.8 0.8 1.3 0.2 0.6
CZ14 0.6 0.7 0.8 0.9 1.4 0.2 0.6
CZ15 0.2 0.2 0.3 0.3 0.7 0.1 0.5
CZ16 1.4 1.7 1.7 1.9 2.3 1.0 1.1
Cost-Effectiveness Analysis: Single Family New Construction 34 Results
California Energy Codes & Standards | A statewide utility program 2024-04-26 Table 21: ADU Greenhouse Gas Reductions (metric tons)
Climate
Zone
ADU All-Electric ADU Mixed Fuel
Code
Minimum
Efficiency
Only
Efficiency
+ High
Efficiency
Equipment
Efficiency
+ PV
Efficiency
+ PV +
Battery
Efficiency + High Efficiency
Equipment
Efficiency
+ PV +
Battery
CZ01 0.4 0.5 0.5 0.6 1.0 0.2 0.5
CZ02 0.2 0.3 0.3 0.4 0.8 0.1 0.5
CZ03 0.5 0.5 0.6 0.7 1.0 0.1 0.3
CZ04 0.5 0.5 0.5 0.7 1.0 0.1 0.4
CZ05 0.1 0.2 0.2 0.3 0.7 0.0 0.4
CZ06 0.1 0.1 0.1 0.3 0.6 0.0 0.4
CZ07 0.1 0.1 0.1 0.3 0.6 0.0 0.4
CZ08 0.1 0.1 0.1 0.3 0.6 0.0 0.5
CZ09 0.1 0.1 0.1 0.3 0.7 0.0 0.5
CZ10 0.1 0.1 0.2 0.2 0.6 0.0 0.4
CZ11 0.2 0.3 0.3 0.3 0.7 0.1 0.4
CZ12 0.2 0.3 0.3 0.4 0.7 0.1 0.5
CZ13 0.4 0.5 0.5 0.5 0.9 0.1 0.3
CZ14 0.4 0.5 0.5 0.7 1.1 0.1 0.5
CZ15 0.1 0.1 0.1 0.2 0.6 0.0 0.4
CZ16 0.4 0.5 0.5 0.7 1.0 0.2 0.6
Cost-Effectiveness Analysis: Single Family New Construction 35 Results
California Energy Codes & Standards | A statewide utility program 2024-04-26
4.6 Sensitivity Analysis
In response to jurisdictional interest, several cases were evaluated under circumstances different than those presented above in order to assess their impact on cost-effectiveness. Altered circumstances include:
1. CARE versus standard tariffs. This comparison is presented for the all-electric Code Minimum and the mixed fuel Efficiency + PV+ Battery packages and shows the impact on On-Bill cost-effectiveness for income qualified utility customers.
2. Infill versus new subdivision single family developments. This comparison applied to the all-electric Code Minimum package demonstrates how costeffectiveness is impacted due to the magnitude of cost savings for all-electric construction from elimination of the natural gas infrastructure.
3. Utility rate escalation factors. The impact on On-Bill cost-effectiveness is presented for the all-electric Code Minimum package from varying the assumptions for escalation of electricity and natural gas utility rates over the 30-year analysis period.
Cost-Effectiveness Analysis: Single Family New Construction 36 Results
California Energy Codes & Standards | A statewide utility program 2024-04-26
4.6.1 CARE Rate Comparison
Table 22 and Table 23 present a comparison of On-Bill cost-effectiveness results for CARE tariffs relative to standard IOU tariffs for the all-electric Code Minimum package for the single family and ADU prototypes, respectively. Applying the CARE rates lowers both electric and gas utility bills for the consumer. In the case of the all-electric home, the net impact of CARE rates is improved cost-effectiveness relative to the standard tariffs. This is because the discount on electricity is greater than that for natural gas. The opposite trend occurs for the mixed fuel packages, where the lower CARE rates result in lower utility cost savings and subsequently lower benefit-to-cost ratios.
Table 22: On-Bill Cost-Effectiveness with CARE Tariffs: All-Electric Code Minimum Climate
Zone
Electric
/Gas Utility
Single Family ADU
Standard CARE Standard CARE
B/C Ratio NPV B/C Ratio NPV B/C Ratio NPV B/C Ratio NPV CZ01 PGE 0.9 ($268) >1 $3,886 0.7 ($2,077) 1.2 $696
CZ02 PGE 1.6 $2,355 5.1 $5,107 0.7 ($1,742) 1.1 $580
CZ03 PGE 1.0 ($90) 1.7 $1,968 0.0 ($7,581) 0.0 ($4,596) CZ04 PGE 1.3 $979 2.3 $2,619 0.0 ($7,406) 0.0 ($4,526)
CZ05 PGE 1.3 $1,373 2.2 $3,467 0.7 ($1,912) 1.1 $237
CZ05 PGE/SCG 1.4 $1,823 2.5 $3,841 0.9 ($574) 1.4 $1,321 CZ06 SCE/SCG 1.6 $2,339 2.3 $3,535 0.9 ($318) 1.4 $1,225 CZ07 SDGE 1.1 $624 2.1 $3,309 0.6 ($3,298) 0.9 ($627)
CZ08 SCE/SCG 1.7 $2,792 2.3 $3,945 0.9 ($289) 1.4 $1,231 CZ09 SCE 1.7 $2,831 2.4 $4,074 0.9 ($310) 1.4 $1,230
CZ10 SCE/SCG 1.6 $2,642 2.4 $4,083 1.3 $976 1.7 $1,923
CZ10 SDGE 1.4 $1,825 3.0 $4,642 0.8 ($1,084) 1.3 $1,114 CZ11 PGE 1.7 $2,552 5.0 $5,077 1.0 $200 1.6 $1,634
CZ12 PGE 1.9 $3,210 5.0 $5,587 0.7 ($1,710) 1.1 $545
CZ13 PGE 1.5 $1,480 2.7 $2,924 0.0 ($4,131) 0.0 ($2,754) CZ14 SCE/SCG 0.9 ($522) 1.3 $1,191 0.0 ($7,375) 0.0 ($4,754) CZ14 SDGE 0.7 ($1,717) 2.0 $2,295 0.0 ($10,790) 0.0 ($6,496) CZ15 SCE/SCG 1.4 $1,791 1.9 $2,831 1.4 $1,246 1.8 $2,031 CZ16 PG&E 0.2 ($5,394) 0.8 ($351) 0.6 ($2,562) 1.1 $453 Cost-Effectiveness Analysis: Single Family New Construction 37 Results
California Energy Codes & Standards | A statewide utility program 2024-04-26 Table 23: On-Bill Cost-Effectiveness with CARE Tariffs: Mixed Fuel Efficiency + PV+ Battery Package Climate
Zone
Electric
/Gas Utility
Single Family ADU
Standard CARE Standard CARE
B/C Ratio NPV B/C Ratio NPV B/C Ratio NPV B/C Ratio NPV CZ01 PGE 1.3 $6,501 0.9 ($2,072) 0.96 ($1,040) 0.7 ($9,009) CZ02 PGE 1.1 $2,486 0.7 ($5,286) 1.0 $138 0.7 ($7,683)
CZ03 PGE 1.1 $1,104 0.6 ($5,980) 0.8 ($3,399) 0.6 ($9,288) CZ04 PGE 1.0 $456 0.6 ($6,790) 0.9 ($2,011) 0.6 ($8,586) CZ05 PGE 1.1 $2,285 0.7 ($4,995) 0.4 ($13,922) 0.7 ($6,642) CZ05 PGE/SCG 1.1 $2,154 0.7 ($5,100) 1.1 $1,246 0.7 ($6,657) CZ06 SCE/SCG 1.1 $1,951 0.7 ($5,232) 0.97 ($575) 0.7 ($5,976) CZ07 SDGE 1.6 $9,869 1.1 $1,601 1.4 $8,825 0.9 ($2,435) CZ08 SCE/SCG 1.2 $3,344 0.7 ($4,574) 1.0 $755 0.8 ($5,331) CZ09 SCE 1.2 $3,369 0.7 ($4,547) 1.0 $886 0.8 ($5,198)
CZ10 SCE/SCG 1.3 $4,546 0.8 ($3,354) 0.7 ($4,499) 0.5 ($8,010) CZ10 SDGE 1.8 $14,148 1.3 $4,789 1.2 $3,065 0.8 ($3,001) CZ11 PGE 1.4 $6,523 0.9 ($3,358) 0.9 ($2,295) 0.6 ($8,074) CZ12 PGE 1.2 $3,451 0.7 ($5,212) 1.1 $1,786 0.7 ($6,653) CZ13 PGE 1.3 $5,665 0.8 ($4,024) 0.8 ($3,335) 0.5 ($8,497) CZ14 SCE/SCG 1.3 $5,945 0.8 ($3,665) 1.0 $346 0.7 ($5,727) CZ14 SDGE 1.8 $15,726 1.2 $4,127 1.5 $10,386 0.9 ($1,393) CZ15 SCE/SCG 1.5 $9,078 0.9 ($877) 0.93 ($1,187) 0.6 ($6,708) CZ16 PG&E 1.3 $5,254 0.8 ($3,523) 1.1 $2,037 0.7 ($6,282) Cost-Effectiveness Analysis: Single Family New Construction 38 Results
California Energy Codes & Standards | A statewide utility program 2024-04-26
4.6.2 Utility Infrastructure Cost Sensitivity
Table 24 compares cost-effectiveness results for the natural gas service line extension cost scenarios that inform the average values presented in Table 8. The average cost scenario reflects the cost-effectiveness results for the single family all-electric Code Minimum package presented in Table 16. Relative to a new subdivision, gas infrastructure cost savings are higher for the infill development case, which translates to higher cost-effectiveness. This is shown by positive costeffectiveness in all metrics except one – On-Bill for Climate Zone 16 – for infill development. Compared to the average cost scenario, there are two cases – OnBill for Climate Zone 4 in PG&E territory and Climate Zone 7 – where the all-electric Code Minimum package is no longer cost-effective based on the new subdivision costs.
Table 24: Single Family Cost-Effectiveness Comparison with Range of Natural Gas Utility Infrastructure Costs:
All-Electric Code Minimum
Climate
Zone
Electric
/Gas Utility
Average New Subdivision Infill Development
On-Bill TDV On-Bill TDV On-Bill TDV
B/C Ratio NPV B/C Ratio NPV B/C
Ratio NPV B/C Ratio NPV B/C Ratio NPV B/C Ratio NPV
CZ01 PGE 0.9 ($268) >1 $5,702 0.6 ($1,492) >1 $4,612 2.2 $4,628 >1 $10,062 CZ02 PGE 1.6 $2,355 >1 $7,711 1.3 $1,131 >1 $6,621 2.8 $7,250 >1 $12,071 CZ03 PGE 0.98 ($90) 25.3 $3,887 0.7 ($1,314) 18.5 $2,797 2.0 $4,806 52.6 $8,247 CZ04 PGE 1.3 $979 >1 $4,494 0.9 ($245) >1 $3,404 2.6 $5,875 >1 $8,854 CZ04 CPAU >1 $10,437 >1 $7,762 >1 $10,437 >1 $7,762 >1 $10,437 >1 $7,762 CZ05 PGE 1.3 $1,373 6.1 $4,633 1.0 $149 4.9 $3,543 2.3 $6,269 11.0 $8,993 CZ05 PGE/SCG 1.4 $1,823 6.1 $4,633 1.1 $599 4.9 $3,543 2.5 $6,719 11.0 $8,993 CZ06 SCE/SCG 1.6 $2,339 4.7 $4,353 1.3 $1,115 3.8 $3,263 2.8 $7,235 8.4 $8,713 CZ07 SDGE 1.1 $624 4.2 $4,211 0.9 ($600) 3.4 $3,121 2.0 $5,519 7.5 $8,571 CZ08 SCE/SCG 1.7 $2,792 4.2 $4,674 1.4 $1,568 3.5 $3,584 2.8 $7,687 7.3 $9,034 CZ09 SCE 1.7 $2,831 5.5 $5,013 1.4 $1,607 4.6 $3,923 2.9 $7,726 9.5 $9,373 CZ10 SCE/SCG 1.6 $2,642 7.4 $5,287 1.3 $1,418 6.1 $4,197 2.7 $7,537 12.6 $9,647 CZ10 SDGE 1.4 $1,825 7.4 $5,287 1.1 $601 6.1 $4,197 2.3 $6,721 12.6 $9,647 CZ11 PGE 1.7 $2,552 >1 $7,153 1.3 $1,328 >1 $6,063 3.0 $7,448 >1 $11,513 CZ12 PGE 1.9 $3,210 >1 $7,504 1.5 $1,986 >1 $6,414 3.1 $8,106 >1 $11,864 CZ12 SMUD/PGE >1 $11,714 >1 $7,504 >1 $10,490 >1 $6,414 >1 $16,610 >1 $11,864 CZ13 PGE 1.5 $1,480 >1 $4,490 1.1 $256 >1 $3,400 3.0 $6,376 >1 $8,850 CZ14 SCE/SCG 0.9 ($522) >1 $4,105 0.7 ($1,746) >1 $3,015 1.8 $4,374 >1 $8,465 CZ14 SDGE 0.7 ($1,717) >1 $4,105 0.5 ($2,941) >1 $3,015 1.5 $3,179 >1 $8,465 CZ15 SCE/SCG 1.4 $1,791 3.0 $3,439 1.1 $567 2.4 $2,349 2.6 $6,687 5.6 $7,799 CZ16 PG&E 0.2 ($5,394) 0.4 ($1,339) 0.0 ($6,618) 0.0 ($2,429) 0.9 ($498) 2.4 $3,021 Cost-Effectiveness Analysis: Single Family New Construction 39 Results
California Energy Codes & Standards | A statewide utility program 2024-04-26
4.6.3 Utility Rate Escalation
In this sensitivity analysis, an alternative set of annual utility escalation rates was applied to the gas and electricity savings in select measure packages to show the impact that utility cost changes over time have on cost-effectiveness. This set of rates, detailed in Section 7.2.7, reflects those used by the Energy Commission in their development of the LSC factors for the 2025 code cycle (LSC replaces TDV in the 2025 code cycle). The rates assume steep increases in gas rates starting in 2030. Increased gas rates range from 2% to 6.7% higher than annual rates used in the 2022 code cycle; electricity rates are only marginally (about 0.5%) higher each year.
On-Bill cost-effectiveness results are shown for in Table 25 for the all-electric Code Minimum scenario and Table 26 for the mixed fuel Efficiency + PV + Battery measure package. The alternative rates described above (“2025 LSC”) are shown alongside those reported elsewhere in this report (“CPUC / 2022 TDV”, described in Section 2.1.3) for comparison. In all cases, the 2025 LSC escalation rates improve cost-effectiveness. In some cases, this improvement is enough to change the result from not cost-effective to cost-effective, these cases are summarized below:
• All-Electric Code Minimum package
o Climate Zones 1, 3, 14, and 16 for the single family home o Climate Zones 1, 5 in PG&E/SCG territory, 6, 8, 9, 10 in SDG&E territory, and 16 for the ADU home • Mixed fuel Efficiency + PV + Battery package
o Climate Zones 1, 6, and 15 for the ADU home
Cost-Effectiveness Analysis: Single Family New Construction 40 Results
California Energy Codes & Standards | A statewide utility program 2024-04-26 Table 25: On-Bill Cost-Effectiveness, 2025 LSC Basis: All-Electric Code Minimum Climate
Zone
Electric
/Gas Utility
Single Family ADU
CPUC / 2022 TDV 2025 LSC CPUC / 2022 TDV 2025 LSC
B/C Ratio NPV B/C Ratio NPV B/C Ratio NPV B/C Ratio NPV CZ01 PGE 0.9 ($268) >1 $13,867 0.7 ($2,077) 1.2 $833
CZ02 PGE 1.6 $2,355 >1 $10,458 0.7 ($1,742) 0.95 ($228) CZ03 PGE 0.98 ($90) >1 $4,883 0.0 ($7,581) 0.0 ($4,465) CZ04 PGE 1.3 $979 >1 $5,728 0.0 ($7,406) 0.0 ($4,466)
CZ04 CPAU >1 $10,437 >1 $17,647 6.9 $2,592 20.7 $8,704
CZ05 PGE 1.3 $1,373 5.3 $5,148 0.7 ($1,912) 0.8 ($1,386) CZ05 PGE/SCG 1.4 $1,823 13.5 $5,884 0.9 ($574) 1.2 $807 CZ06 SCE/SCG 1.6 $2,339 4.0 $4,751 0.9 ($318) 1.2 $630
CZ07 SDGE 1.1 $624 1.9 $3,008 0.6 ($3,298) 0.7 ($2,394) CZ08 SCE/SCG 1.7 $2,792 3.0 $4,650 0.9 ($289) 1.1 $591
CZ09 SCE 1.7 $2,831 4.0 $5,233 0.9 ($310) 1.2 $634
CZ10 SCE/SCG 1.6 $2,642 5.4 $5,700 1.3 $976 1.9 $2,147
CZ10 SDGE 1.4 $1,825 7.4 $6,038 0.8 ($1,084) 1.0 $102
CZ11 PGE 1.7 $2,552 >1 $9,997 1.0 $200 1.6 $1,669
CZ12 PGE 1.9 $3,210 >1 $10,077 0.7 ($1,710) 0.9 ($430)
CZ12 SMUD/PGE >1 $11,714 >1 $19,028 5.7 $3,797 >1 $5,367 CZ13 PGE 1.5 $1,480 >1 $5,987 0.0 ($4,131) 0.0 ($1,228) CZ14 SCE/SCG 0.9 ($522) 6.0 $3,876 0.0 ($7,375) 0.0 ($4,363) CZ14 SDGE 0.7 ($1,717) >1 $4,799 0.0 ($10,790) 0.0 ($6,285) CZ15 SCE/SCG 1.4 $1,791 2.2 $3,214 1.4 $1,246 1.9 $2,210 CZ16 PG&E 0.2 ($5,394) >1 $8,516 0.6 ($2,562) 1.2 $629
Cost-Effectiveness Analysis: Single Family New Construction 41 Results
California Energy Codes & Standards | A statewide utility program 2024-04-26 Table 26: On-Bill Cost-Effectiveness, 2025 LSC Basis: Mixed Fuel Efficiency + PV + Battery Climate
Zone
Electric
/Gas Utility
Single Family ADU
CPUC / 2022 TDV 2025 LSC CPUC / 2022 TDV 2025 LSC
B/C Ratio NPV B/C Ratio NPV B/C Ratio NPV B/C Ratio NPV CZ01 PGE 1.3 $6,501 1.6 $12,598 0.96 ($1,040) 1.0 $993
CZ02 PGE 1.1 $2,486 1.3 $4,914 1.0 $138 1.1 $1,816
CZ03 PGE 1.1 $1,104 1.1 $2,287 0.8 ($3,399) 0.9 ($2,462) CZ04 PGE 1.0 $456 1.1 $1,645 0.9 ($2,011) 0.95 ($980)
CZ04 CPAU 0.2 ($16,295) 0.2 ($15,990) 0.4 ($13,922) 0.4 ($13,453) CZ05 PGE 1.1 $2,285 1.3 $4,506 1.1 $1,265 1.1 $2,574
CZ05 PGE/SCG 1.1 $2,154 1.2 $4,291 1.1 $1,246 1.1 $2,543 CZ06 SCE/SCG 1.1 $1,951 1.2 $3,420 0.97 ($575) 1.0 $847 CZ07 SDGE 1.6 $9,869 1.6 $9,930 1.4 $8,825 1.4 $8,570
CZ08 SCE/SCG 1.2 $3,344 1.3 $4,750 1.0 $755 1.1 $2,288
CZ09 SCE 1.2 $3,369 1.3 $4,812 1.0 $886 1.1 $2,407
CZ10 SCE/SCG 1.3 $4,546 1.4 $6,334 0.7 ($4,499) 0.8 ($3,703) CZ10 SDGE 1.8 $14,148 1.9 $14,289 1.2 $3,065 1.2 $2,904 CZ11 PGE 1.4 $6,523 1.4 $7,967 0.9 ($2,295) 0.94 ($1,126) CZ12 PGE 1.2 $3,451 1.3 $4,806 1.1 $1,786 1.1 $3,458
CZ12 SMUD/PGE 0.3 ($13,066) 0.4 ($12,515) 0.5 ($12,564) 0.5 ($11,582) CZ13 PGE 1.3 $5,665 1.4 $6,448 0.8 ($3,335) 0.8 ($2,674) CZ14 SCE/SCG 1.3 $5,945 1.4 $7,138 1.0 $346 1.1 $1,827
CZ14 SDGE 1.8 $15,726 1.8 $15,116 1.5 $10,386 1.5 $10,107 CZ15 SCE/SCG 1.5 $9,078 1.7 $10,819 0.9 ($1,187) 0.99 ($182) CZ16 PG&E 1.3 $5,254 1.5 $10,999 1.1 $2,037 1.2 $4,285
Cost-Effectiveness Analysis: Single Family New Construction 42 Summary
California Energy Codes & Standards | A statewide utility program 2024-04-26 5 Summary
The purpose of this study was to examine and document the code compliance and cost-effectiveness impacts of improving performance among single family new construction – both standard sized homes and ADUs. To this end, the Reach Codes Team evaluated packages of energy efficiency measures as well as packages combining energy efficiency with solar PV generation and battery storage, simulated them in building modeling software, and gathered costs to determine the cost-effectiveness of multiple scenarios. The Reach Codes Team coordinated with multiple utilities, cities, and building community experts to develop a set of assumptions considered reasonable in the current market. Changing assumptions, such as the period of analysis, measure selection, cost assumptions, energy escalation rates, or utility tariffs are likely to change results.
Table 27 (single family) and Table 28 (ADU) summarize results for each prototype and depict the EDR1 compliance margins achieved for each climate zone and package. Because local reach codes must both exceed the energy code (i.e., have a positive compliance margin in the performance approach) and be cost-effective, the Reach Codes Team highlighted cells meeting these two requirements to help clarify the upper boundary for potential reach code policies.
All results presented in this study have a positive compliance margin. • Cells highlighted in green depict a positive compliance margin and cost-effective results using both On-Bill and TDV approaches.
• Cells highlighted in yellow depict a positive compliance and cost-effective results using either the On-Bill or TDV approach.
• Cells not highlighted depict a package that was not cost-effective using either the On-Bill or TDV approach. • Cells highlighted in grey depict the high efficiency equipment packages where cost-effectiveness was not evaluated.
The following are key takeaways and recommendations from the analysis.
Conclusions and Discussion:
• All-electric buildings have lower GHG emissions than mixed fuel buildings, due to the clean power sources currently available from California’s power providers as well as accounting for increased penetration of renewables in the future. Almost all the all-electric packages evaluated resulted in greater GHG emission savings than the mixed fuel packages, with the exception of the mixed fuel package with battery storage in climate zones with low heating loads. The Reach Codes Team found code-compliant, all-electric new construction to be feasible and cost-effective based on TDV for single family homes in all cases except Climate Zone 16.
• All-electric single family new construction was On-Bill cost-effective in all cases except Climate Zones 1, 3, 14, and 16.
• The all-electric ADU home was cost-effective based on TDV in all cases except in Climate Zones 3, 4, 13, and 14 where the higher cost of installing a ducted HPWH instead of the prescriptively required gas tankless water heater outweigh the resulting energy cost savings. In the other climate zones there were first cost savings for installing a heat pump space heater instead of gas furnace, contributing to an overall TDV cost-effective result. • Few cases were cost-effective On-Bill for the ADU.
• All-electric code minimum construction results in an increase in first year utility costs relative to a mixed fuel home, except for CPAU and SMUD where electricity rates are much lower than for the IOUs. The addition of efficiency measures, market dominant HPWHs that meet NEEA’s Advanced Water Heating Specification, high efficiency heat pumps, increased PV, and batteries all reduce utility costs, and a combination of these options was found to reduce annual utility costs relative to a mixed fuel home in all cases. • Under NBT, utility cost savings for increasing PV system size beyond code minimum are substantially less than under prior net energy metering rules (NEM 2.0); however, savings are sufficient to be On-Bill costeffective in all climate zones for the all-electric single family home. Coupling PV with battery systems increases utility cost savings as a result of improved on-site utilization of PV generation and fewer exports to the grid.
Cost-Effectiveness Analysis: Single Family New Construction 43 Summary
California Energy Codes & Standards | A statewide utility program 2024-04-26 • Applying CARE rates in the IOU territories increases improves On-Bill cost-effectiveness for all-electric buildings, as compared to the same case under standard rates, due to higher utility cost savings compared to a code compliant mixed fuel building also on a CARE rate, improving On-Bill cost-effectiveness. This is due to the CARE discount on electricity being higher than that on gas. • If gas tariffs are assumed to increase substantially over time, in-line with the escalation assumption from the 2025 LSC development, all-electric new construction was found to be On-Bill cost-effective in almost all scenarios over the 30-year analysis period. There is much uncertainty surrounding future tariff structures as well as escalation values. While it’s clear that gas rates will increase, how much and how quickly is not known.
Electricity tariff structures are expected to evolve over time, and the CPUC has an active proceeding to adopt an income-graduated fixed charge that benefits low-income customers and supports electrification measures.21 The CPUC will make a decision in mid-2024 and the new rates are expected to be in place later that year or in 2025. While the anticipated impact of this rate change is lower volumetric electricity rates, the rate design is not finalized. While lower volumetric electricity rates provide many benefits including incentivizing electrification, it also will make building efficiency measures harder to justify as cost-effective due to lower utility bill cost savings.
Recommendations:
• A reach code with a single performance target based on source energy (EDR1) can be structured to strongly encourage electrification. This approach requires equivalent performance for all buildings and allows mixed fuel buildings which minimizes the risk of violating federal preemption. Below are examples of how a reach code for single family homes could be setup based on the results summarized in Table 27. o A jurisdiction in Climate Zone 12 could set a performance target at an EDR1 margin of 11.5 (the EDR1 margin for the all-electric Code Minimum package). Any all-electric home meeting or exceeding the prescriptive requirements would comply, and a mixed fuel home would likely need to incorporate a combination of efficiency measures and a battery system to comply. o Similarly, a jurisdiction in Climate Zone 7 may consider setting a performance target of 2.8 EDR1 margin (also the EDR1 margin for the all-electric Code Minimum package). Any all-electric home meeting or exceeding the prescriptive requirements would comply, but a mixed fuel home would likely be able to comply with only a suite of above-code efficiency measures (no battery). Alternatively, a higher EDR1 margin target of 5 would incentivize more energy efficiency or additional PV for allelectric construction, and mixed fuel construction would likely need to incorporate a battery system to comply.
o A jurisdiction in Climate Zone 16 may want to set a performance target at an EDR1 margin of 20.5 (the EDR1 margin for the mixed fuel efficiency + PV + battery package). This would establish a target that a mixed fuel home could cost-effectively meet, likely only after incorporating a combination of efficiency measures and a battery system, and that an all-electric home could easily meet. • The 2022 Title 24 code’s new source energy metric combined with the heat pump baseline encourage allelectric construction, providing an incentive that allows for some amount of prescriptively required building efficiency to be traded off, still meeting minimum code compliance. This compliance benefit for all-electric homes highlights a unique opportunity for jurisdictions to incorporate efficiency into all-electric reach codes.
Efficiency and electrification have symbiotic benefits and are both critical for decarbonization of buildings. As demand on the electric grid is increased through electrification, efficiency can reduce the negative impacts of additional electricity demand on the grid, reducing the need for increased generation and storage capacity, as well as the need to upgrade upstream transmission and distribution equipment. The Reach Codes Team recommends that jurisdictions adopting a reach code for single family buildings also include an efficiency requirement with EDR1 margins at minimum consistent with the all-electric code minimum package results in Table 27.
21 https://www.cpuc.ca.gov/industries-and-topics/electrical-energy/electric-costs/demand-response-dr/demand-flexibility-rulemaking Cost-Effectiveness Analysis: Single Family New Construction 44 Summary
California Energy Codes & Standards | A statewide utility program 2024-04-26 • The code compliance margins for the ADU all-electric code minimum package are lower than for the single family prototype; code compliance and cost-effectiveness can be more challenging for smaller dwelling units.
As a result, the Reach Codes Team does not recommend EDR1 targets above those reported for the allelectric Code Minimum package in Table 28.
Local jurisdictions may also adopt ordinances that amend different Parts of the California Building Standards Code or may elect to amend other state or municipal codes. The decision regarding which code to amend will determine the specific requirements that must be followed for an ordinance to be legally enforceable. For example, jurisdictions may amend Part 11 instead of Part 6 of the CA Building Code requiring review and approval by the BSC but not the Energy Commission. Reach codes that amend Part 6 of the CA Building Code and require energy performance beyond state code minimums must demonstrate the proposed changes are cost-effective and obtain approval from the Energy Commission.
This report documents the key results and conclusions from the Reach Codes Team analysis. A full dataset of all results can be downloaded at https://localenergycodes.com/content/resources. Results alongside policy options can also be explored using the Cost-effectiveness Explorer at https://explorer.localenergycodes.com/.
Table 27: Summary of Single Family EDR1 Margins and Cost-Effectiveness Climate
Zone
Electric
/Gas Utility
All-Electric Mixed Fuel
Code
Minimum Efficiency
Efficiency +
High
Efficiency
Equipment
Efficiency
+ PV
Efficiency
+ PV +
Battery
Efficiency +
High
Efficiency
Equipment
Efficiency
+ PV +
Battery
CZ01 PGE 25.8 29.1 31.4 32.6 41.4 14.8 22.6
CZ02 PGE 14.0 16.3 18.0 18.9 28.3 9.1 14.1
CZ03 PGE 9.1 10.6 12.2 13.1 24.2 3.6 12.8
CZ04 PGE 8.8 10.4 11.9 12.8 24.6 3.8 13.2
CZ04 CPAU 8.8 10.4 11.9 12.8 24.6 3.8 13.2
CZ05 PGE 6.5 7.9 10.2 10.8 23.3 5.2 14.8
CZ05 PGE/SCG 6.5 7.9 10.2 10.8 23.3 5.2 14.8
CZ06 SCE/SCG 4.2 5.3 6.6 8.4 24.6 4.0 18.3
CZ07 SDGE 2.8 3.6 4.8 6.9 23.6 3.2 18.7
CZ08 SCE/SCG 2.1 2.9 4.2 5.6 21.3 2.7 17.1
CZ09 SCE/SCG 3.6 4.4 5.7 7.1 21.8 3.2 16.2
CZ10 SCE/SCG 4.8 5.8 7.2 8.5 21.9 3.9 14.4
CZ10 SDGE 4.8 5.8 7.2 8.5 21.9 3.9 14.4
CZ11 PGE 11.4 13.4 15.0 15.6 24.5 7.7 12.9
CZ12 PGE 11.5 13.3 14.8 15.5 25.2 7.2 13.2
CZ12 SMUD/PGE 11.5 13.3 14.8 15.5 25.2 7.2 13.2
CZ13 PGE 8.3 10.3 11.9 12.3 22.3 4.1 12.3
CZ14 SCE/SCG 8.8 11.5 13.2 14.3 24.7 4.6 13.4
CZ14 SDGE 8.8 11.5 13.2 14.3 24.7 4.6 13.4
CZ15 SCE/SCG 0.9 2.4 3.7 3.8 15.7 3.5 13.5
CZ16 PG&E 21.3 25.6 27.0 29.1 37.5 16.3 20.4
Cost-Effectiveness Analysis: Single Family New Construction 45 Summary
California Energy Codes & Standards | A statewide utility program 2024-04-26 Table 28: Summary of ADU EDR1 Margins and Cost-Effectiveness Climate
Zone
Electric
/Gas Utility
All-Electric Mixed Fuel
Code
Minimum Efficiency
Efficiency +
High
Efficiency
Equipment
Efficiency
+ PV
Efficiency
+ PV +
Battery
Efficiency +
High
Efficiency
Equipment
Efficiency
+ PV +
Battery
CZ01 PGE 11.9 15.7 18.5 19.3 33.7 2.9 18.5
CZ02 PGE 5.7 7.9 9.7 10.8 25.6 -4.7 16.6
CZ03 PGE 2.9 4.0 5.9 7.1 23.2 4.0 11.8
CZ04 PGE 2.4 3.9 5.5 6.8 23.6 4.2 13.3
CZ04 CPAU 2.4 3.9 5.5 6.8 23.6 4.2 13.3
CZ05 PGE 1.8 2.9 4.8 6.4 24.0 -12.1 16.9
CZ05 PGE/SCG 1.8 2.9 4.8 6.4 24.0 -12.1 16.9
CZ06 SCE/SCG 0.5 1.3 2.6 5.0 25.7 -15.6 19.8
CZ07 SDGE 0.1 0.9 2.1 5.0 26.4 -16.5 20.3
CZ08 SCE/SCG 0.1 0.7 1.8 4.2 25.1 -15.3 20.4
CZ09 SCE 0.4 1.1 2.3 4.5 25.0 -14.4 19.6
CZ10 SCE/SCG 1.0 2.0 3.5 5.4 25.3 -11.9 19.0
CZ10 SDGE 1.0 2.0 3.5 5.4 25.3 -11.9 19.0
CZ11 PGE 4.6 7.0 8.6 9.6 25.1 -3.5 17.6
CZ12 PGE 4.6 6.6 8.3 9.3 24.5 -5.6 16.7
CZ12 SMUD/PGE 4.6 6.6 8.3 9.3 24.5 -5.6 16.7
CZ13 PGE 3.1 5.5 6.9 7.8 25.2 4.4 14.5
CZ14 SCE/SCG 3.5 6.3 8.0 9.6 26.9 5.1 14.5
CZ14 SDGE 3.5 6.3 8.0 9.6 26.9 5.1 14.5
CZ15 SCE/SCG 0.0 2.2 2.6 4.4 25.3 -9.3 19.2
CZ16 PG&E 11.2 14.7 15.7 18.3 33.7 2.9 18.3
Cost-Effectiveness Analysis: Single Family New Construction 46 References
California Energy Codes & Standards | A statewide utility program 2024-04-26 6 References
Barbose, G., Darghouth, N., O'Shaughnessy, E., & Forrester, S. (2021, October). Tracking the Sun. Pricing and Design Trends for Distributed Photovoltaic Systems in the United States 2021 Edition. Retrieved from https://emp.lbl.gov/tracking-the-sun
Barbose, Galen; Darghouth, Naim; O'Shaughnessy, Eric; Forrester, Sydney. (2022). Tracking the Sun: Pricing and Design Trends for Distributed Photovoltaic Systems in the United States 2022 Edition. Retrieved from https://emp.lbl.gov/tracking-the-sun
California Energy Commission. (2017). Rooftop Solar PV System. Measure number: 2019-Res-PV-D Prepared by Energy and Environmental Economics, Inc. Retrieved from https://efiling.energy.ca.gov/getdocument.aspx?tn=221366 California Energy Commission. (2018). 2019 Alternative Calculation Method Approval Manual for the 2019 Building Energy Efficiency Standards. Retrieved from https://www.energy.ca.gov/publications/2018/2019-alternativecalculation-method-approval-manual-2019-building-energy California Energy Commission. (2021a). Express Terms for the Proposed Revisions to 2022 Title 24, Part 1 and Part 6.
Retrieved from https://efiling.energy.ca.gov/Lists/DocketLog.aspx?docketnumber=21-BSTD-01 California Energy Commission. (2021b). Final Express Terms for the Proposed Revisions to the 2022 Energy Code Reference Appendices. Retrieved from https://efiling.energy.ca.gov/Lists/DocketLog.aspx?docketnumber=21- BSTD-01
California Energy Commission. (2022, Feb). 2022 Single-Family Residential Alternative Calculation Method Reference Manual. Retrieved from https://www.energy.ca.gov/publications/2022/2022-single-family-residentialalternative-calculation-method-reference-manual California Public Utilities Commission. (2021a). Utility Costs and Affordability of the Grid of the Future: An Evaluation of Electric Costs, Rates, and Equity Issues Pursuant to P.U. Code Section 913.1. Retrieved from https://www.cpuc.ca.gov/-/media/cpuc-website/divisions/office-of-governmental-affairsdivision/reports/2021/senate-bill-695-report-2021-and-en-banc-whitepaper_final_04302021.pdf California Public Utilities Commission. (2021b). Database for Energy-Efficient resources (DEER2021 Update). Retrieved April 13, 2021, from http://www.deeresources.com/index.php/deer-versions/deer2021 California Public Utilities Commission. (2022). Proposed Decision of Commissioner Rechtschaffen: PHASE III DECISION
ELIMINATING GAS LINE EXTENSION ALLOWANCES, TEN-YEAR REFUNDABLE PAYMENT OPTION, AND FIFTY PERCENT DISCOUNT PAYMENT OPTION UNDER GAS LINE EXTENSION RULES.
Department of Energy. (2022). Preliminary Analysis Technical Support Document: Energy Efficiency Program for Consumer Products and Commercial and Industrial Equipment. Retrieved from https://www.regulations.gov/document/EERE-2017-BT-STD-0019-0018 E-CFR. (2020). https://www.ecfr.gov/cgibin/retrieveECFR?gp=&SID=8de751f141aaa1c1c9833b36156faf67&mc=true&n=pt10.3.431&r=PART&ty=HTM L#se10.3.431_197. Retrieved from Electronic Code of Federal Regulations: https://www.ecfr.gov/cgibin/retrieveECFR?gp=&SID=8de751f141aaa1c1c9833b36156faf67&mc=true&n=pt10.3.431&r=PART&ty=HTM L#se10.3.431_197
Energy & Environmental Economics. (2019). Residential Building Electrification in California. Retrieved from https://www.ethree.com/wpcontent/uploads/2019/04/E3_Residential_Building_Electrification_in_California_April_2019.pdf Energy + Environmental Economics. (2020). Time Dependent Valuation of Energy for Developing Building Efficiency Standards: 2022 Time Dependent Valuation (TDV) and Source Energy Metric Data Sources and Inputs.
E-Source companies. (2020). Behind-the-Meter Battery Market Study. Prepared for San Diego Gas & Electric.
Retrieved from https://www.etcc-ca.com/reports/behind-meter-battery-market-study?dl=1582149166 Cost-Effectiveness Analysis: Single Family New Construction 47 References
California Energy Codes & Standards | A statewide utility program 2024-04-26 Horii, B., Cutter, E., Kapur, N., Arent, J., & Conotyannis, D. (2014). Time Dependent Valuation of Energy for Developing Building Energy Efficiency Standards.
Proctor, J., Wilcox, B., & Chitwood, R. (2018). Central Valley Research Homes Project. California Energy Commission.
Retrieved from
https://www.researchgate.net/publication/342135376_Central_Valley_Research_Homes_Project_-- _Final_CEC_Report
RSMeans. (2022). Cost data obtained from the 2022 RSMeans online database.
Statewide CASE Team. (2017). Residential High Performance Windows & Doors Codes and Standards Enhancement (CASE) Initiative 2019 California Energy Code. Retrieved from http://title24stakeholders.com/wpcontent/uploads/2017/09/2019-T24-CASE-Report_Res-Windows-and-Doors_Final_September-2017.pdf Statewide CASE Team. (2018). Energy Savings Potential and Cost-Effectiveness Analysis of High Efficiency Windows in California. Prepared by Frontier Energy. Retrieved from https://www.etcc-ca.com/reports/energy-savingspotential-and-cost-effectiveness-analysis-high-efficiency-windows-california Statewide CASE Team. (2020a). Nonresidential High Performance Envelope Codes and Standards Enhancement (CASE) Initiative 2022 California Energy Code. Prepared by Energy Solutions. Retrieved from https://title24stakeholders.com/wp-content/uploads/2020/10/2020-T24-NR-HP-Envelope-Final-CASEReport.pdf Statewide CASE Team. (2020b). Residential Energy Savings and Process Improvements for Additions and Alterations Codes and Standards Enhancement (CASE) Initiative 2022 California Energy Code. Prepared by Frontier Energy. Retrieved from https://title24stakeholders.com/wp-content/uploads/2020/08/SF-Additions-andAlterations_Final_-CASE-Report_Statewide-CASE-Team.pdf Statewide CASE Team. (2020c). Multifamily All-Electric Codes and Standards Enhancement (CASE) Initiative 2022 California Energy Code. Prepared by TRC.
Statewide Reach Codes Team. (2019, August). 2019 Cost-effectiveness Study: Low-Rise Residential New Construction.
Prepared for Pacific Gas and Electric Company. Prepared by Frontier Energy. Retrieved from https://localenergycodes.com/download/800/file_path/fieldList/2019%20Res%20NC%20Reach%20Codes Statewide Reach Codes Team. (2021a). Cost-Effectiveness Analysis: Batteries in Single Family Homes. Prepared by Frontier Energy. Retrieved from
https://localenergycodes.com/download/930/file_path/fieldList/Single%20Family%20Battery%20Costeff%20Report.pdf Statewide Reach Codes Team. (2021b). 2020 Reach Code Cost-Effectiveness Analysis: Detached Accessory Dwelling Units. Prepared by TRC. Retrieved from
https://localenergycodes.com/download/760/file_path/fieldList/2019%20New%20Detached%20ADUs%20Co st-effectiveness%20Report.pdf
Statewide Reach Codes Team. (tbd). 2022 Cost-Effectiveness Study: Existing Single Family Building Upgrades.
Prepared by Frontier Energy. Not yet published.
TRC, P. E. (2021). 2020 Reach Code Cost-Effectiveness Analysis: Detached Accessory Dwelling Units.
UC Berkeley Center for Community Innovation. (2021). Implementing the Backyard Revolution: Perspectives of California’s ADU Owners.
Cost-Effectiveness Analysis: Single Family New Construction 48 Appendices
California Energy Codes & Standards | A statewide utility program 2024-04-26 7 Appendices
7.1 Map of California Climate Zones
Climate zone geographical boundaries are depicted in Figure 4. The map in Figure 4 along with a zip-code search directory is available at: https://ww2.energy.ca.gov/maps/renewable/building_climate_zones.html Figure 4: Map of California climate zones.
Cost-Effectiveness Analysis: Single Family New Construction 49 Appendices
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7.2 Utility Rate Schedules
The Reach Codes Team used the CA IOU and POU rate tariffs detailed below to determine the On-Bill savings for each package. The California Climate Credit was applied for both electricity and natural gas service for the IOUs using the 2023 credits shows below.22 The credits were applied to reduce the total calculated annual bill, including any fixed fees or minimum bill amounts.
Electricity rates reflect the most recently approved tariffs. Monthly gas rates were estimated based on recent gas rates (November 2023) and a curve to reflect how natural gas prices fluctuate with seasonal supply and demand. The seasonal curve was estimated from monthly residential tariffs between 2014 and 2023 (between 2017 and 2023 for CPAU). 12-month curves were created from monthly gas rates for each of the ten years (seven years for CPAU).
These annual curves were then averaged to arrive at an average normalized annual curve. This was conducted separately for baseline and excess energy rates. Costs used in this analysis were then derived by establishing the most recent baseline and excess rate from the latest tariff as a reference point (November 2023), and then using the normalized curve to estimate the cost for the remaining months relative to the reference point rate. 22 https://www.cpuc.ca.gov/industries-and-topics/natural-gas/greenhouse-gas-cap-and-trade-program/california-climate-credit Cost-Effectiveness Analysis: Single Family New Construction 50 Appendices
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7.2.1 Pacific Gas & Electric
The following pages provide details on the PG&E electricity and natural gas tariffs applied in this study. Table 29 describes the baseline territories that were assumed for each climate zone. A net surplus compensation rate of $0.07051/ kWh was applied to any net annual electricity generation based on a one-year average of the rates between December 2022 and November 2023.
Table 29: PG&E Baseline Territory by Climate Zone
Climate
Zone
Baseline
Territory
CZ01 V
CZ02 X
CZ03 T
CZ04 X
CZ05 T
CZ11 R
CZ12 S
CZ13 R
CZ16 Y
The PG&E monthly gas rate for G-1 in $/therm was applied on a monthly basis according to the rates shown in Table
30. These rates are based on applying a normalization curve to the November 2023 tariff based on ten years of historical gas data. Corresponding CARE rates reflect the 20 percent discount per the GL-1 tariff.
Table 30: PG&E Monthly Gas Rate ($/therm)
Month Total Charge
Baseline Excess
January $2.05 $2.43
February $2.08 $2.46
March $1.92 $2.31
April $1.80 $2.20
May $1.77 $2.18
June $1.78 $2.18
July $1.80 $2.20
August $1.85 $2.26
September $1.92 $2.33
October $1.99 $2.40
November $2.06 $2.46
December $2.05 $2.44
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7.2.2 Southern California Edison
The following pages provide details on the SCE electricity tariffs applied in this study. Table 31 describes the baseline territories that were assumed for each climate zone. A net surplus compensation rate of $ 0.06030/ kWh was applied to any net annual electricity generation based on a one-year average of the rates between December 2022 and November 2023.
Table 31: SCE Baseline Territory by Climate Zone
Climate
Zone
Baseline
Territory
CZ06 6
CZ08 8
CZ09 9
CZ10 10
CZ14 14
CZ15 15
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7.2.3 Southern California Gas
Following are the SoCalGas natural gas tariffs applied in this study. Table 32 describes the baseline territories that were assumed for each climate zone.
Table 32: SoCalGas Baseline Territory by Climate Zone
Climate
Zone
Baseline
Territory
CZ05 2
CZ06 1
CZ08 1
CZ09 1
CZ10 1
CZ14 2
CZ15 1
The SoCalGas monthly gas rate in $/therm was applied on a monthly basis according to the rates shown in Table 33.
These rates are based on applying a normalization curve to the November 2023 tariff based on ten years of historical gas data. Long-term historical natural gas rate data was only available for SoCalGas’ procurement charges.23 The baseline and excess transmission charges were found to be consistent over the course of a year and applied for the entire year based on 2023 rates. CARE rates reflect the 20 percent discount per the GR tariff.
Table 33: SoCalGas Monthly Gas Rate ($/therm)
Month Procurement
Charge
Transportation Charge Total Charge
Baseline Excess Baseline Excess
January $0.72 $0.86 $1.31 $1.92 $2.36
February $0.50 $0.86 $1.31 $1.57 $2.02
March $0.44 $0.86 $1.31 $1.48 $1.93
April $0.39 $0.86 $1.31 $1.39 $1.84
May $0.41 $0.86 $1.31 $1.43 $1.87
June $0.46 $0.86 $1.31 $1.49 $1.93
July $0.47 $0.86 $1.31 $1.51 $1.96
August $0.51 $0.86 $1.31 $1.58 $2.03
September $0.46 $0.86 $1.31 $1.52 $1.96
October $0.45 $0.86 $1.31 $1.48 $1.92
November $0.48 $0.86 $1.31 $1.54 $1.99
December $0.57 $0.86 $1.31 $1.63 $2.08
23 The SoCalGas procurement and transmission charges were obtained from the following site: https://www.socalgas.com/for-yourbusiness/energy-market-services/gas-prices RES2023.xlsx (live.com) Cost-Effectiveness Analysis: Single Family New Construction 62 Appendices
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7.2.4 San Diego Gas & Electric
Following are the SDG&E electricity and natural gas tariffs applied in this study. Table 34 describes the baseline territories that were assumed for each climate zone. A net surplus compensation rate of $0.04542/ kWh was applied to any net annual electricity generation based on a one-year average of the rates between December 2022 and November 2023.
Table 34: SDG&E Baseline Territory by Climate Zone
Climate
Zone
Baseline
Territory
CZ07 Coastal
CZ10 Inland
CZ14 Mountain
The SDG&E monthly gas rate in $/therm was applied on a monthly basis according to the rates shown in Table
35. These rates are based on applying a normalization curve to the November 2023 tariff based on ten years of historical gas data. CARE rates reflect the 20 percent discount per the G-CARE tariff.
Table 35: SDG&E Monthly Gas Rate ($/therm)
Month Total Charge
Baseline Excess
January $2.34 $2.63
February $2.28 $2.57
March $2.21 $2.51
April $2.14 $2.45
May $2.18 $2.48
June $2.23 $2.55
July $2.26 $2.57
August $2.32 $2.62
September $2.26 $2.59
October $2.21 $2.55
November $2.24 $2.57
December $2.38 $2.70
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7.2.5 City of Palo Alto Utilities
Following are the CPAU electricity and natural gas tariffs applied in this study. The CPAU monthly gas rate in $/therm was applied on a monthly basis according to the rates shown in Table 36. These rates are based on applying a normalization curve to the October 2023 tariff based on seven years of historical gas data. The monthly service charge applied was $14.01 per month per the November 2023 G-1 tariff.
Table 36: CPAU Monthly Gas Rate ($/therm)
Month G1
Volumetric
Total
Baseline
G1
Volumetric
Total
Excess
January $1.83532 $3.35639
February $1.38055 $2.59947
March $1.32506 $2.47695
April $1.29680 $2.44038
May $1.29511 $2.43804
June $1.32034 $2.45406
July $1.35688 $2.61519
August $1.40696 $2.67944
September $1.42130 $2.70301
October $1.42310 $2.48300
November $1.46286 $2.45547
December $1.62415 $2.62128
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7.2.6 Sacramento Municipal Utilities District (Electric Only) Following are the SMUD electricity tariffs applied in this study. The rates effective January 2023 were used.
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7.2.7 Fuel Escalation Assumptions
The average annual escalation rates in Table 37 were used in this study. These are based on assumptions from the CPUC 2021 En Banc hearings on utility costs through 2030 (California Public Utilities Commission, 2021a). Escalation rates through the remainder of the 30-year evaluation period are based on the escalation rate assumptions within the 2022 TDV factors. No data was available to estimate electricity escalation rates for CPAU and SMUD, therefore electricity escalation rates for PG&E and statewide natural gas escalation rates were applied. Table 38 presents the average annual escalation rates used in the utility rate escalation sensitivity analysis shown in Section 4.6.3. Rates were applied for the same 30-year period and are based on the escalation rate assumptions within the 2025 LSC factors from 2027 through 2053.24 These rates were developed for electricity use statewide (not utility-specific) and assume steep increases in gas rates in the latter half of the analysis period. Data was not available for years 2024, 2025, and 2026 and so the CPUC En Banc assumptions were applied for those years using the average rate across the three IOUs for statewide electricity escalation.
Table 37: Real Utility Rate Escalation Rate Assumptions, CPUC En Banc and 2022 TDV Basis
24 https://www.energy.ca.gov/files/2025-energy-code-hourly-factors. Actual escalation factors were provided by consultants E3.
Year
Statewide Natural
Gas Residential
Average Rate
(%/year, real)
Electric Residential Average Rate
(%/year, real)
PG&E SCE SDG&E
2024 4.6% 1.8% 1.6% 2.8%
2025 4.6% 1.8% 1.6% 2.8%
2026 4.6% 1.8% 1.6% 2.8%
2027 4.6% 1.8% 1.6% 2.8%
2028 4.6% 1.8% 1.6% 2.8%
2029 4.6% 1.8% 1.6% 2.8%
2030 4.6% 1.8% 1.6% 2.8%
2031 2.0% 0.6% 0.6% 0.6%
2032 2.4% 0.6% 0.6% 0.6%
2033 2.1% 0.6% 0.6% 0.6%
2034 1.9% 0.6% 0.6% 0.6%
2035 1.9% 0.6% 0.6% 0.6%
2036 1.8% 0.6% 0.6% 0.6%
2037 1.7% 0.6% 0.6% 0.6%
2038 1.6% 0.6% 0.6% 0.6%
2039 2.1% 0.6% 0.6% 0.6%
2040 1.6% 0.6% 0.6% 0.6%
2041 2.2% 0.6% 0.6% 0.6%
2042 2.2% 0.6% 0.6% 0.6%
2043 2.3% 0.6% 0.6% 0.6%
2044 2.4% 0.6% 0.6% 0.6%
2045 2.5% 0.6% 0.6% 0.6%
2046 1.5% 0.6% 0.6% 0.6%
2047 1.3% 0.6% 0.6% 0.6%
2048 1.6% 0.6% 0.6% 0.6%
2049 1.3% 0.6% 0.6% 0.6%
2050 1.5% 0.6% 0.6% 0.6%
2051 1.8% 0.6% 0.6% 0.6%
2052 1.8% 0.6% 0.6% 0.6%
2053 1.8% 0.6% 0.6% 0.6%
Cost-Effectiveness Analysis: Single Family New Construction 73 Appendices
California Energy Codes & Standards | A statewide utility program 2024-04-26 Table 38: Real Utility Rate Escalation Rate Assumptions, 2025 LSC Basis Year
Statewide Natural
Gas Residential
Average Rate
(%/year, real)
Statewide
Electricity
Residential
Average Rate
(%/year, real)
2024 4.6% 2.1%
2025 4.6% 2.1%
2026 4.6% 2.1%
2027 4.2% 0.6%
2028 3.2% 1.9%
2029 3.6% 1.6%
2030 6.6% 1.3%
2031 6.7% 1.0%
2032 7.7% 1.2%
2033 8.2% 1.1%
2034 8.2% 1.1%
2035 8.2% 0.9%
2036 8.2% 1.1%
2037 8.2% 1.1%
2038 8.2% 1.0%
2039 8.2% 1.1%
2040 8.2% 1.1%
2041 8.2% 1.1%
2042 8.2% 1.1%
2043 8.2% 1.1%
2044 8.2% 1.1%
2045 8.2% 1.1%
2046 8.2% 1.1%
2047 3.1% 1.1%
2048 -0.5% 1.1%
2049 -0.6% 1.1%
2050 -0.5% 1.1%
2051 -0.6% 1.1%
2052 -0.6% 1.1%
2053 -0.6% 1.1%
Cost-Effectiveness Analysis: Single Family New Construction 74 Appendices
California Energy Codes & Standards | A statewide utility program 2024-04-26
7.3 Summary of Efficiency Measures
Table 39 provides the details of the efficiency (non-preempted) measures, by climate zone, included in the following all-electric packages for the single family prototype:
• Efficiency Only
• Efficiency + High Efficiency (Preempted) Equipment
• Efficiency + PV
• Efficiency + PV + Battery
The efficiency measures for the single family mixed fuel packages are presented in Table 40, and Table 41 presents the efficiency measures for all the ADU packages. In all tables, the lack of an “X” indicates that the prescriptive values for that climate zone were not changed. See Appendix 7.4 for a list of prescriptive values by climate zone. Efficiency measures are described in Section 3.3.1.
Table 39: All-Electric Single Family Efficiency Measures, Various Packages Climate
Zone
3 ACH50
R-10
Slab
Attic Ceiling
Insulation
0.25 Roof
Solar
Reflectance
0.24 U-Factor /
0.50 SHGC
Windows
0.35 W/cfm
Buried
Ducts
Basic Compact
Hot Water
Credit
1 X R-60 X
2 X R-60 X X X
3 R-60 X X X
4 X R-60 X X X
5 X1 R-49 X X X
6 R-60 X X X
7 R-49 X X
8 R-60 X X X
9 R-60 X X X
10 R-60 X X X X
11 X R-60 X X X X
12 X R-60 X X X X
13 X R-60 X X X X
14 X X R-60 X X X X
15 X R-60 X X X X
16 R-60 X X X 1 This measure in Climate Zone 5 was only evaluated for the Efficiency + PV + Battery package.
Cost-Effectiveness Analysis: Single Family New Construction 75 Appendices
California Energy Codes & Standards | A statewide utility program 2024-04-26 Table 40: Mixed Fuel Single Family Measures, Efficiency Only & Efficiency + PV + Battery Packages
Climate
Zone
3 ACH50
R-10
Slab
Attic:
EE Only
Attic:
EE + PV
+ Bat
0.25 Roof
Solar
Reflectance
0.24 UFactor / 0.50
SHGC
Windows
0.30 UFactor / 0.50
SHGC
Windows
0.35 W/cfm
Buried
Ducts
CDHW1:
EE Only
CDHW:
EE + PV
+ Bat
1 X R-60 vs R-38 X X
2 X R-60 vs R-38 R-49 X X X X
3 R-60 vs R-30 R-38 X EE Only X X
4 X R-60 vs R-38 R-49 X X X
5 R-60 vs R-38 R-49 X X X X
6 R-49 vs R-30 R-49 X X X X
7 R-49 vs R-30 R-49 X X X
8 R-60 vs R-30 R-49 X X X X
9 R-49 vs R-30 R-49 X X X X
10 R-60 vs R-38 X X X X X
11 X R-60 vs R-38 R-49 X X X X X
12 X R-60 vs R-38 R-49 X X X X X
13 X R-60 vs R-38 R-49 X X X X
14 X X R-60 vs R-38 R-49 X X X X
15 X R-60 vs R-38 R-49 X X X X X
16 R-60 vs R-38 R-49 X X X 1 CDHW stands for basic Compact Domestic Hot Water credit Table 41: Efficiency Measures for All ADU Packages
Climate
Zone
3 ACH50
R-10
Slab Attic1
0.25 Roof
Solar
Reflectance
0.24 U-Factor /
0.50 SHGC
Windows
Ductless
VCHP2
Basic
Compact Hot
Water Credit
3 1 X R-60 vs R-38 X
2 X R-60 vs R-38 X X
3 R-60 vs R-30 X X
4 X R-60 vs R-38 X X
5 R-60 vs R-38 X X
6 R-60 vs R-30 X X
7 R-60 vs R-30 X X
8 R-60 vs R-30 X X
9 R-60 vs R-30 X X
10 R-60 vs R-38 X X X
11 X R-60 vs R-38 X X X
12 X R-60 vs R-38 X X X
13 X R-60 vs R-38 X X X
14 X X R-60 vs R-38 X X X
15 X R-60 vs R-38 X X X
16 R-60 vs R-38 X X 1 This measure was added to all ADU packages except the Mixed Fuel Efficiency + High Efficiency Equipment package. 2 The ductless VCHP measure was only applied to the all-electric packages; the mixed fuel packages instead applied
0.35 W/cfm fans in Climate Zones 2, 4-6, and 8-15. 3 The compact hot water measure was only applied to the all-electric packages.
Cost-Effectiveness Analysis: Single Family New Construction 76 Appendices
California Energy Codes & Standards | A statewide utility program 2024-04-26
7.4 Summary of Applicable Prescriptive Base Case Measures This appendix lists the prescriptive values, by climate zone, of building components relevant to the measures included in this analysis. Table 42 outlines envelope, PV, and battery values; Table 43 outlines space conditioning values, and Table 44 outlines domestic water heating (DHW) values.
Table 42: Prescriptive Envelope, PV, and Battery Measures by Climate Zone CZ Air
Infiltration1 Foundation Wall
Insulation2
Attic
Insulation3
Roof Aged
Solar
Reflectivity
Window
U-Factor /
SHGC
PV4 Battery
1 5 ACH50 Uninsulated slab R-21 + R-5 R-38 0.1 0.30 / 0.35 code min. none 2 5 ACH50 Uninsulated slab R-21 + R-5 R-38 0.1 0.30 / 0.23 code min. none 3 5 ACH50 Uninsulated slab R-21 + R-5 R-30 0.1 0.30 / 0.35 code min. none 4 5 ACH50 Uninsulated slab R-21 + R-5 R-38 + R-19 0.1 0.30 / 0.23 code min. none 5 5 ACH50 Uninsulated slab R-21 + R-5 R-30 0.1 0.30 / 0.35 code min. none 6 5 ACH50 Uninsulated slab R-15 + R-4 R-30 0.1 0.30 / 0.23 code min. none 7 5 ACH50 Uninsulated slab R-15 + R-4 R-30 0.1 0.30 / 0.23 code min. none 8 5 ACH50 Uninsulated slab R-21 + R-5 R-38 + R-19 0.1 0.30 / 0.23 code min. none 9 5 ACH50 Uninsulated slab R-21 + R-5 R-38 + R-19 0.1 0.30 / 0.23 code min. none 10 5 ACH50 Uninsulated slab R-21 + R-5 R-38 + R-19 0.2 0.30 / 0.23 code min. none 11 5 ACH50 Uninsulated slab R-21 + R-5 R-38 + R-19 0.2 0.30 / 0.23 code min. none 12 5 ACH50 Uninsulated slab R-21 + R-5 R-38 + R-19 0.2 0.30 / 0.23 code min. none 13 5 ACH50 Uninsulated slab R-21 + R-5 R-38 + R-19 0.2 0.30 / 0.23 code min. none 14 5 ACH50 Uninsulated slab R-21 + R-5 R-38 + R-19 0.2 0.30 / 0.23 code min. none 15 5 ACH50 Uninsulated slab R-21 + R-5 R-38 + R-19 0.2 0.30 / 0.23 code min. none 16 5 ACH50 R-7, 16” slab
insulation R-21 + R-5 R-38 + R-19 0.1 0.30 / 0.35 code min. none 1 5 ACH50 is prescriptively required however verification is not required. 2 Cavity wall insulation + continuous rigid insulation. 3 Ceiling/attic insulation R-value. R-38 + R-19 reflect High Performance Attics (HPAs) as defined by Option B in Table 150.1-A. 4 Prescriptive PV capacities (kW-DC) by climate zone are summarized in Table 4.
Cost-Effectiveness Analysis: Single Family New Construction 77 Appendices
California Energy Codes & Standards | A statewide utility program 2024-04-26 Table 43: Prescriptive HVAC Measures by Climate Zone
CZ Heating
Type AC Type HeatingEfficiency1
HVAC
Efficiency
(SEER2/EER2)
HVAC Fan
Efficacy
(W/cfm)
Ducts2
1 Gas Furnace AC 80% 14.3 / 11.7 0.45 R-8, 5%, in attic (not buried) 2 Gas Furnace AC 80% 14.3 / 11.7 0.45 R-8, 5%, in attic (not buried) 3 Heat pump Heat pump 7.5 14.3 / 11.7 0.45 R-6, 5%, in attic (not buried) 4 Heat pump Heat pump 7.5 14.3 / 11.7 0.45 R-8, 5%, in attic (not buried) 5 Gas Furnace AC 80% 14.3 / 11.7 0.45 R-6, 5%, in attic (not buried) 6 Gas Furnace AC 80% 14.3 / 11.7 0.45 R-6, 5%, in attic (not buried) 7 Gas Furnace AC 80% 14.3 / 11.7 0.45 R-6, 5%, in attic (not buried) 8 Gas Furnace AC 80% 14.3 / 11.7 0.45 R-8, 5%, in attic (not buried) 9 Gas Furnace AC 80% 14.3 / 11.7 0.45 R-8, 5%, in attic (not buried) 10 Gas Furnace AC 80% 14.3 / 11.7 0.45 R-8, 5%, in attic (not buried) 11 Gas Furnace AC 80% 14.3 / 11.7 0.45 R-8, 5%, in attic (not buried) 12 Gas Furnace AC 80% 14.3 / 11.7 0.45 R-8, 5%, in attic (not buried) 13 Heat pump Heat pump 7.5 14.3 / 11.7 0.45 R-8, 5%, in attic (not buried) 14 Heat pump Heat pump 7.5 14.3 / 11.7 0.45 R-8, 5%, in attic (not buried) 15 Gas Furnace AC 80% 14.3 / 11.7 0.45 R-8, 5%, in attic (not buried) 16 Gas Furnace AC 80% 14.3 / 11.7 0.45 R-8, 5%, in attic (not buried) 1 AFUE for gas furnaces, HSPF2 for heat pumps. 2 Duct insulation R-value, duct leakage, duct location.
Table 44: Prescriptive Water Heating Measures by Climate Zone CZ DHW Type
DHW Location DHW:
Basic
Compact
Distribution
Credit
Single
Family ADU
1 Heat pump Garage In conditioned space, ducted to/from outside Yes 2 Heat pump Garage In conditioned space, ducted to/from outside No 3 Gas tankless Garage In conditioned space, ducted to/from outside No 4 Gas tankless Garage In conditioned space, ducted to/from outside No 5 Heat pump Garage In conditioned space, ducted to/from outside No 6 Heat pump Garage In conditioned space, ducted to/from outside No 7 Heat pump Garage In conditioned space, ducted to/from outside No 8 Heat pump Garage In conditioned space, ducted to/from outside No 9 Heat pump Garage In conditioned space, ducted to/from outside No 10 Heat pump Garage In conditioned space, ducted to/from outside No 11 Heat pump Garage In conditioned space, ducted to/from outside No 12 Heat pump Garage In conditioned space, ducted to/from outside No 13 Gas tankless Garage In conditioned space, ducted to/from outside No 14 Gas tankless Garage In conditioned space, ducted to/from outside No 15 Heat pump Garage In conditioned space, ducted to/from outside No 16 Heat pump Garage In conditioned space, ducted to/from outside Yes Cost-Effectiveness Analysis: Single Family New Construction 78 Appendices
California Energy Codes & Standards | A statewide utility program 2024-04-26 Get In Touch
The adoption of reach codes can differentiate jurisdictions as efficiency leaders and help accelerate the adoption of new equipment, technologies, code compliance, and energy savings strategies.
As part of the Statewide Codes & Standards Program, the Reach Codes Subprogram is a resource available to any local jurisdiction located throughout the state of California.
Our experts develop robust toolkits as well as provide specific technical assistance to local jurisdictions (cities and counties) considering adopting energy reach codes. These include cost-effectiveness research and analysis, model ordinance language and other code development and implementation tools, and specific technical assistance throughout the code adoption process.
If you are interested in finding out more about local energy reach codes, the Reach Codes Team stands ready to assist jurisdictions at any stage of a reach code project.
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Please Note:
This template is intended for educational purposes only, without any express or implied warranty of any kind, including warranties of accuracy, completeness, or fitness for any particular purpose. You agree that your use of the template is without any recourse whatsoever to PG&E, SCE, SDG&E, or their affiliates. The template is a draft, and anyone using this document should seek the advice of an attorney to develop appropriate ordinance language to meet its jurisdiction’s specific needs, as state and local laws may differ.
Please contact the Codes and Standards Reach Codes Team at [email protected] for additional information.
This program is funded by California utility customers and administered by Pacific Gas and Electric Company, San Diego Gas & Electric Company (SDG&E®), and Southern California Edison Company under the auspices of the California Public Utilities Commission and in support of the California Energy Commission. 1 2022 Single Family FlexPath Model Reach
Code for Existing Buildings
FAQs
May 2024
Q. What do the points represent?
A. The points in the Measure Menu table represent the relative site energy savings attributable to each measure. Thus, a measure with 4 points would provide twice as much savings as a measure with only 2 points.
The Target Score represents a user-defined (see below) percentage of the maximum cost-effective site energy savings, (the sum of points from all retrofit measures that have been found to be cost-effective). Thus, in the Cost-Effectiveness Explorer if the Target Score is set at 50% of the maximum score, the required measures would save about 50% as much energy as the energy savings attributable to installing all costeffective measures.
Q. How are the Target Score and Measure Points calculated? A. The Cost-Effectiveness Explorer calculates the Maximum Target Score and the points tables, which are available for export. The user (i.e., staff developing the policy) sets the required Target Score in the Cost Effectiveness Explorer.
Q. What is considered cost-effective?
A. Cost-effectiveness assumes that the bill payer will accrue a positive net-present-value from the measure. For the scope of this policy, the cost is assumed to be the full retrofit cost and is not contingent upon a project. Measures that are only cost-effective during replacements (e.g., appliances and cool roofs) are not part of the set of measures used to establish the cost-effective ceiling.
Q. Could points be based on GHG reductions?
A. Federal regulations1require that, among other things, local and state standards to be based on energy or its equivalent energy cost savings. Site energy savings are generally proportionate to GHG emissions reductions.
Q. Why are some measures mandatory?
A. Cost-effective measures with very low costs and small savings (i.e., lighting) are recommended to be mandatory to prevent cream skimming.
Electric readiness is presented as mandatory because there are no directly attributable energy savings and therefore it cannot be scored relative to the other measures.
Q. How can I tell how much compliance might cost?
A. The cost of compliance will vary based on a) the Target Score, b) the scope of project, c) the existing conditions of the home, d) measure selection, and e) market conditions. By 1 42 USCode Sec. 6297(f)(3)(F). https://www.govinfo.gov/content/pkg/USCODE-2022-title42/pdf/USCODE2022-title42-chap77-subchapIII-partA-sec6297.pdf 2 adjusting the Target Score in the Cost Effectiveness Explorer, the user alters the measure combinations that satisfy the requirements.
Typical initial measure costs, as reported in the cost-effectiveness study, are presented below. Costs may vary by climate zone. In addition to the information in the table, the Cost Effectiveness Explorer produces an estimate of the typical compliance costs for a range of Target Scores specific to each climate zone and vintage.
Typical Measure Costs – 2,400 Sq. Ft. Home ($)
Pre-1978 1978-1991 1992-2010
Lighting Measures 100 100 100
Water Heating Package 300 300 300
Air sealing 4,700 4,700 4,700
R-38 Attic insulation 6,800 2,600 2,600
R-49 Attic insulation 7,500 3,700 3,700
Duct sealing 2,600 2,600 2,600
New ducts, R-6 insulation + duct sealing 4,900 4,900 4,900 New ducts, R-8 insulation + duct sealing 6,400 6,400 6,400 Windows 11,900 11,900 11,900
Wall Insulation 3,000 na na
R-19 Raised Floor Insulation 3,700 3,700 3,700
R-30 Raised Floor Insulation 4,200 4,200 4,200
Cool roof .20 Solar Reflectance * 900 900 900
Cool roof .25 Solar Reflectance * 1,800 1,800 1,800
Radiant barrier under roof * 900 900 900
Heat pump water heater replacing gas * 4,400 4,400 4,400 High eff. heat pump water heater replacing gas * 5,200 5,200 5,200 Heat pump water heater replacing electric * 3,900 3,900 3,900 High eff. heat pump water heater replacing electric * 4,700 4,700 4,700 Heat pump space heater * 1,100 1,100 1,100
High eff. heat pump space heater * 4,100 4,100 4,100
Dual fuel heat pump space heater * 2,000 2,000 2,000
Heat Pump Clothes Dryer * 400 400 400
Induction Cooktop * 700 700 700
Solar PV (3kW) 9,700 9,700 9,700
* Incremental cost at time of replacement
Q. Why do some measures have points which exceed the Maximum Target Score? A. The points are based on site energy savings; they do not vary based on the Target Score.
Measures with values that exceed the Target Score save more energy than required.
Q. Can a jurisdiction alter the points and score?
A. Jurisdictions may (and should) alter the Target Score but may not change the measure points. Users will need documentation supporting the relative energy value of the measure(s) to alter the measure points.
Q. Can other measures be added to the list?
A. If there is documentation supporting site energy savings, additional measures may be added. Contact [email protected] to inquire about revisions.
Q. Why do some measures have no points for newer vintages? A. Certain measures (e.g., windows, wall insulation) were required at the time of construction in newer vintages and are therefore not eligible for points. 3 Q. How would this ordinance be implemented?
A. Specific implementation details will depend upon the triggers, stringency, and scope of each adopted ordinance. Projects that are required to comply with the ordinance would be required to install a combination of measures from the menu that meets or exceeds the Target Score. Permit applicants would submit a supplemental form documenting that the measures selected and installed meet or exceed the Target Score. Collateral materials have been developed to assist implementation. These materials include: an application checklist; air-sealing checklist; and an exceptions form.
Q. What if compliance would be very onerous because only a few measures are applicable or technically feasible in the home?
A. There is an exception that allows the Building Administrator to adjust the Target Score.
The exception form provides specific values for those measures that were used to set Target Score, which can be applied as credits. If those measures are deemed to be not applicable (e.g., ducts in a home with hydronic heating) or infeasible (e.g., PV with excessive shading), the Administrator may reduce the Target Score by the value of those measures.
Q. How do the vintages account for code cycles that became effective mid-year? A. Normally, codes become effective on January 1 of the year following the nominal code cycle. However, in some cycles the effective date was postponed to midyear. In these cases, the vintages are rounded down such that a home permitted anytime during that year is credited with the code effective in the latter half of the year. 1 Building Reach Code Proposal for Existing Construction Policy Snapshot
May 6, 2024
Reach Code Proposal
Every three years the Building codes are updated at the State level and at that time local jurisdictions are allowed and encouraged to adopt more stringent “reach codes” to help conserve resources and address climate goals. The City Council adopted a Green Building Reach Codes in November 2022 for new construction which went into effect January 2023. Included in the reach code were prohibitions on gas piping for most new construction, a prohibition on extending gas lines or meters for existing single-family homes, and an increase in electric vehicle charging infrastructure for multifamily buildings to reduce barriers to adoption of electric vehicles. A recent court decision against the City of Berkeley has rendered the gas prohibitions in the reach code null and void. However, the electric vehicle requirements have not been affected and remain in place.
A second part of the reach code process was to identify technical assistance and streamlining opportunities to remove barriers to electrification and more robust energy efficiency in construction.
Staff worked with two local residents who recently electrified their homes to develop an 8 Steps Guide to Electrification that has been well-received and promoted by the Marin Builders Association among others. In addition, staff has been working with partners around the County to develop an electrification roadmap for longer term transition to electric appliances in response to interest by residents to electrify. This roadmap, being developed by the County for use countywide, should be finalized sometime this fall.
Climate Change Action Plan (CCAP) Measures addressed by this proposal
1. Green Building Reach Code (EE-C4)
2. Building and Appliance Electrification (RE-C3)
3. Energy Efficiency Programs (EE-C1)
Green Building Reach Codes have been estimated to contribute between 2.9 – 10.7% of the City’s total 2030 greenhouse gas (GHG) reduction goal. In addition, reduction in energy use saves on energy bills and reduction of natural gas use in homes contributes to healthier living environments for tenants.
The Issue
Existing buildings make up a large portion of the City’s building stock and GHG emissions. These buildings will need to be retrofitted to significantly improve their energy efficiency, their appliances will need to be electrified, or on-site renewable energy such as solar panels will need to be installed to meet City emission reduction goals. Single family homes make up the majority of San Rafael’s existing housing stock and will be key in reducing emissions. Targeting emissions in existing buildings is 2 complex, as there is no one-size-fits-all policy option. Given this, the Flexible Compliance Path provides a way to target these emissions in a more equitable and cost-effective way for homeowners.
The Flex Path Proposal
Single-family remodel projects over 500 square feet will be required to comply with the Flexible Compliance Path, or “Flex Path,” which seeks to increase energy efficiency and encourage electrification in homes, while homeowners are already making significant changes to their homes, and without mandating specific requirements.
The Flex Path serves as a menu of energy saving measure options that homeowners can choose from that the State of California has verified for cost-effectiveness. Each measure has an associated point value based on site energy savings. The higher the energy savings from implementation, the higher the score for the measure. The first section of the menu is centered around envelope related efficiency measures such as insulation, windows, and duct sealing, the next section is heating, venting and air conditioning (HVAC) and water heating electrification measures, and the third section consists of solar measures.
Jurisdictions set a “target score” that projects are required to meet, using the points from implementing measures on the menu. The City has set a target score for each vintage of home in a way that does not force electrification and would be achievable through multiple combinations of other measures such as envelope improvements and solar. Each home can choose which measures work best for their home and budget.
Who will it apply to?
Single family remodel projects over 500 square feet, built before 2010.
How will it work?
When homeowners apply for permits, the Flex Path will be a part of their permit paperwork. The form will include the Flex Path Table showing measures, target scores, and points, as well as a detailed description of each measure.
Homeowners will fill in the Flex Path Table for their project. They will note the vintage of their home, which indicates which target score they need to achieve. Then, they will decide which measures they want to implement into their project to meet that target score. They will be able to refer to detailed descriptions of each measure and compare it to the home’s existing conditions. If any measures already exist in the home, the homeowner will provide documentation of these measures, to show compliance with those requirements as long as they meet the efficiency standards in each measure category. For example, if a homeowner installed solar several years ago and it meets the standards in that measure, they would receive the points toward their target score.
If the homeowner looks at the list of measures and there are none already existing in the home, or if the total of any existing measures do not add up to meet the target score, the homeowner would then 3 decide which measures to implement to reach the target score for their vintage. In some instances homeowners may also be eligible for exemption from some or all of the requirements based on factors such as infeasibility or cost burden, which are stipulated in the ordinance.
After implementing their choice of efficiency measures, the homeowner provides documentation of how they’ve met the target score and the completed Flex Path form to the City to show compliance.
Once they’ve shown compliance or exemption from the Flex Path requirement, homeowners and their contractors would continue with the rest of the building permit process.
What do we hope to expect?
It is estimated that 40-60 projects per year will be subject to this requirement. The Flex Path gives project applicants the option to choose energy efficient measures that make the most sense for their home. Though target scores were selected to be low enough not to require any electrification measures, most electrification measures have higher point totals and would allow applicants to comply more quickly than choosing some other measures. Staff will monitor progress and actual projects to gather data on what happens. After one or two years the City could decide to increase target scores to encourage more efficiency measures or change the thresholds for compliance to smaller projects.
How much will it cost and how will it be funded?
There will be no cost to the City, however estimated upfront costs for homeowners may range between $500-$4,000 depending on which measures a project chooses to implement. Most homeowners will see energy bill savings after implementation. Some homeowners may choose more expensive measures while others choose lower cost options, and there will be variety in energy bill impacts as well. The design of the Flex Path is to give homeowners more choices to do what is best for them.
Challenges and Opportunities
Rapid decarbonization will not always be easy to do in all cases. One of the main questions posed at the outset of this project was how to best meet our GHG reduction goals while also meeting our housing production and economic development goals, especially as it relates to cost. Exemptions and exceptions have been built into the proposal to accommodate those occasional cases where it would be infeasible or prohibitively costly to meet the code. In addition, credits are given to homes that have already done measures in the Flex Path.
Another question posed had to do with resiliency: How do electric appliances fare during a power outage, and can the electrical grid handle the increase in demand? Currently many gas appliances require electricity to operate, meaning in many cases space heating and hot water impacts will be felt by those in mixed-fuel homes as well. According to PG&E local power distribution has been hardened and the vast majority of San Rafael is not at threat of a Public Safety Power Shutoff event. Common power outages are lasting shorter amounts of time than just a few short years ago. California is investing billions of dollars in grid reliability and backup power to reduce these impacts even further.
Utilities believe the grid will not be compromised with the investments the State and utilities are making to ensure reliability.
4 Economy and Social Equity
For single family homes, duplexes, town homes and ADUs most energy measures are relatively inexpensive as part of the overall cost of renovation and show on-bill cost savings over time.
Electrification of appliances has less on-bill savings but are not required measures under the Flex Path.
Multifamily housing and commercial projects are not subject to the proposed regulation either. There are numerous incentives to help offset initial costs of installation for many measures through the Inflation Reduction Act, utility programs, the Bay Area Regional Energy Network, and the State of California
With projected increases in extreme heat events, building electrification can provide residents with highly efficient air conditioning at about ¼ the energy use of typical air conditioners. This is because heat pump space heaters can reverse the flow of air and provide cool air as well as heat, offering tenants air conditioning options that were previously out of reach.
Co-Benefits & Potential Unintended Consequences
Two potential unintended consequences of adopting a reach code are additional costs and confusion for contractors due to hard-to-understand code language and burdensome Building Division implementation. However, the City of San Rafael’s Building Division demonstrates collaboration and simplification and was consistently referenced as the easiest to work with in Marin during engagements with builders and the Marin Builders Association. Other potential unintended consequences may include the challenges of installing and using new technologies, added time and associated costs for permitting transformers for larger projects, and the ability to find contractors that can do the work. The City will continue to work with our regional partners to compile and promote all the technical assistance and incentives available to owners and contractors for ease of implementation in the coming year. Electrify Marin and Bay Area Regional Energy Network have been training contractors and providing incentives to build the capacity necessary to transition to an electric future and have seen a thousand-fold increase in qualified contractors since 2019.
Co-benefits include resident health and workforce development. Over 40 studies have documented the negative health effects of having natural gas (methane) in the home, including asthma, increased deaths and illness. Local workforce programs include MCE’s Workforce, Education and Training program in conjunction with Strategic Energy Innovations focused on building electrification and energy efficiency. More workforce programs are being funded and developed across the region and the City is actively exploring opportunities to enhance them for local residents through our Equitable Low Carbon Economy project and work with the California/Bay Area Jobs First initiative. 5 Sources & References
Climate Change Action Plan Measures
• San Rafael Climate Action Plan Energy Efficiency Measures • San Rafael Climate Action Plan Renewable Energy Measures • Marin Climate GHG Inventories
• City of San Rafael 8 Steps Guide to Electrification
• UCLA Report Residential Gas Appliances
• Health Impacts of Natural Gas Stanford Study
• Health Impacts of Natural Gas Meta Analysis
Reach Code Proposal
• Statewide Reach Codes Website
• Single Family Cost Effectiveness Study Updated for 2024 • Cost Effectiveness Explorer for San Rafael Measures
• Marin County Model Reach Code Development
• California Energy Commission Building Decarb and EV Resources Challenges and Opportunities
• Assessment of Impacts of Electrifying Residential Buildings in California • BUILD Program for Technical Assistance and Incentives Multifamily • CPUC Utility Costs and Affordability Evaluation
• Building Decarbonization Practice Guide
• PG&E Public Safety Power Shutoff Map
• MCE Electric Load Planning
Economy and Social Equity
• Low-Rise Residential Cost-Effectiveness Study
• Electrify Marin Rebate Program
• Inflation Reduction Act Fact Sheet
• Inflation Reduction Act Incentives Calculator
• California Eliminates Natural Gas Subsidies
Co-benefits & Potential Unintended Consequences
• Bay Area Regional Energy Network Resources for Public, Government, and Contractors • San Rafael Equitable Low Carbon Economy Project
• Heat Pumps and Heat Waves, Rocky Mountain Institute*
6 • California/Bay Area Jobs First initiative
• MCE Workforce Program
Engagement
• Model Reach Code Development Engagements
• Letter of Support from PG&E for Marin County Model Reach Code