Title 24 · California Energy Code

Community/shared solar or shared BESS programs and how they offset code requirements

If your building joins an Energy Commission‑approved community/shared solar or shared battery program, that shared system can replace the on‑site PV/BESS portion of your building’s energy budget — but only if the program is approved under Title 24, Part 1 § 10‑115 and the offset is calculated and documented using the Commission’s ACM methods and included in your Certificate of Compliance per the Energy Code (see § 170.1/§ 140.1/§ 150.1).

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Last reviewed: July 6, 2026

What the code requires — plain English and the controlling §

Buildings demonstrate compliance with the performance energy budget expressed in long‑term system cost (LSC) and source energy. The Code allows an approved community shared solar electric generation system and/or community shared BESS to offset part or all of the PV/BESS component of the LSC energy budget — but only if the program is approved by the Energy Commission and the offset is calculated using Commission‑established ACM methods. See § 170.1(a) (nonresidential), § 140.1(a) (nonresidential/prescriptive note), and the residential equivalent § 150.1(b)1 for single‑family buildings.

If an Energy‑Commission‑approved community/shared solar or BESS program provides dedicated power or bill reduction credits/payments to the permitted building, that shared system can be counted in the building’s LSC budget in lieu of on‑site PV/BESS — but only to the extent and by the calculation methods the Commission prescribes.

Requirements in detail

Key defined terms (first use bolded)

  • Long‑term system cost (LSC) — the LSC energy budget, used in the performance approach, combines Efficiency LSC (space‑conditioning, water heating, ventilation, lighting, self‑utilization) and Total LSC (adds PV, BESS, demand flexibility). § 170.1(a) and § 140.1(a) define these components.
  • Community/shared solar and community/shared BESS — a renewable electric generation system or battery system that provides dedicated power, utility energy reduction credits, or payments for energy bill reductions to the permitted building and is approved by the Energy Commission per Title 24, Part 1, § 10‑115.
  • ACM Reference Manual — the Commission’s Alternative Calculation Method (ACM) manuals (Residential and Nonresidential) provide the specific calculation procedures by which shared systems may offset required PV/BESS LSC energy. The Code text requires use of those methods.

Decision‑relevant dimensions (quick table)

Decision dimension Typical values/choices What changes compliance Code Reference
Eligible shared resource Community shared PV, other renewable generation, community shared BESS May be used instead of on‑site PV/BESS LSC contribution if approved § 170.1(a) Exception, § 140.1(a) Exception
Approval required Energy Commission approval per Title 24, Part 1 § 10‑115 No offset allowed without this approval § 170.1(a) Exception
Calculation method Commission‑established ACM method (Nonresidential or Residential ACM RM) Determines how much of the PV/BESS LSC is offset § 170.1(a) Exception and residential § 150.1(b)1 Exception
Compliance path affected Performance approach (LSC budget) — Sections § 140.1, § 170.1, and residential § 150.1 Shared resource offsets apply to the PV/BESS portion of the LSC budget under performance § 140.1(a), § 170.1(a), § 150.1(b)1
Documentation required at permit Certificate of Compliance and permit application documentation per Sections 10‑103(a)1 & (a)2; use approved calculation software/method Must be submitted with permit to show source energy and LSC demonstrate compliance § 170.1(b)1 (see code notes)
Residential note Residential ACM provides the method for single‑family shared programs Residential offsets follow Residential ACM methods § 150.1(b)1 Exception

How the offset functions (short)

  • The shared system replaces the portion of the PV/BESS LSC that would otherwise be credited to on‑site PV/BESS in the building’s Total LSC calculation. The share and method are set by the Commission’s ACM manuals — you must use the appropriate ACM (Nonresidential or Residential) calculation method to quantify the offset. § 170.1(a) and § 140.1(a) require this.

Exceptions & special cases

  • Energy Commission approval is mandatory: no program can be used for compliance offsets unless it has been approved per Title 24, Part 1, § 10‑115 (this approval requirement is repeated in the Exception language).
  • The Exception language appears in multiple places: § 140.1(a), § 150.1(b)1 (single‑family), and § 170.1(a) (multifamily/nonresidential performance). Confirm which section applies to your building type when preparing compliance documents.
  • The Code does not change the requirement that the permit application include the standard documentation showing that the proposed design does not exceed the standard design energy budgets; the shared program offset must be demonstrated using approved ACM calculations and included in the Certificate of Compliance materials per the Code’s Certificate/permit rules (see § 170.1(b)1).
  • The Commission sets the exact offset calculation rules in the ACM manuals — if the ACM method for a specific program is not available or the program is not approved, you cannot apply the offset. The Code text points to the Nonresidential and Residential ACM Reference Manuals for the method.

Common mistakes

  • Treating any utility or LSE program as automatically acceptable. Only programs approved under § 10‑115 are eligible. The Code’s Exception is explicit about Energy Commission approval.
  • Attempting to apply an offset without using the ACM calculation method. The Exception requires the offset be “calculated according to methods established by the Commission in the … ACM Reference Manual.” Do not substitute ad‑hoc crediting.
  • Forgetting to include shared‑system documentation in the Certificate of Compliance / permit application. Performance compliance still requires the permit application materials showing source energy and LSC compliance per § 170.1(b)1.
  • Confusing prescriptive exemptions (e.g., PV/BESS exceptions in § 140.10 or § 150.1 prescriptive reductions) with the ACM‑based community/shared offsets; they are separate mechanisms and have different triggers and documentation. See the relevant exceptions in § 140.10 and § 150.1 for prescriptive rules and exceptions.

Worked example — concrete scenario

Scenario: A 20,000 ft² nonresidential building in a climate zone requires a minimum PV capacity that would contribute X LSC points to the Total LSC under the standard design. Instead of installing full on‑site PV/BESS, the owner enrolls the building in an Energy‑Commission‑approved community shared solar program that provides a dedicated bill credit equal to the required on‑site generation.

Steps and numbers (illustrative):

  1. The compliance software (using the Nonresidential ACM method) calculates the building’s Efficiency LSC = 100 LSC‑units and on‑site PV/BESS LSC credit = 30 LSC‑units, so the Total LSC standard budget = 130 LSC‑units.
  2. The proposed design without on‑site PV has Efficiency LSC = 95 LSC‑units and on‑site PV/BESS = 0. With no offset, proposed Total LSC = 95 LSC‑units (favorable vs. budget) — but the design still must show how the PV/BESS requirement is met or offset.
  3. Using the Commission’s ACM method for the approved community program, the shared system is credited with 25 LSC‑units of PV/BESS value to the permitted building. That shared credit is entered into the ACM calculation per the Nonresidential ACM Reference Manual. Because the ACM method is prescriptive about how to translate program credits into LSC units, the Certificate of Compliance documents that the shared system provides 25 LSC‑units of PV/BESS offset and includes the program approval reference.
  4. Final proposed Total LSC = Efficiency 95 + shared PV/BESS credit 25 = 120 LSC‑units — which is less than the standard design Total LSC budget of 130 LSC‑units; the building demonstrates compliance in the performance approach. The permit application includes the ACM calculation files and the Energy Commission program approval (per § 10‑115) as required under § 170.1(b)1.

Note: The numeric LSC units above are illustrative — the actual LSC crediting and conversion of shared energy to LSC is done by the ACM methods and certified compliance software referenced in the Code. The Code requires use of those methods rather than manual conversions.

Related provisions (quick list)

  • § 170.1(a) — Performance approach energy budget definitions and community/shared exception (nonresidential).
  • § 140.1(a) — Performance approach energy budget definitions and exception allowing community/shared offsets for applicable buildings.
  • § 150.1(b)1 — Single‑family residential performance approach and exception for community/shared offsets (Residential ACM).
  • Title 24, Part 1, § 10‑115 — Energy Commission approval process for community/shared programs (approval required to use a program for code compliance).
  • Certificate/permit documentation requirements — Sections 10‑103(a)1 and 10‑103(a)2 and § 170.1(b)1 (documentation and Certificate of Compliance for performance compliance).
  • ACM Reference Manuals (Residential and Nonresidential) — methods for converting program benefits into LSC offsets (referenced in the exception text).

Code references

Grounded in the retrieved California Energy Code — click a citation to read the verbatim passage:

  • § 170.1 High relevance — show source text

    A. The Efficiency LSC energy is the sum of the LSC energy for space-conditioning, water heating, mechanical ventilation, lighting and the self-utilization credit. B. The Total LSC energy is the sum of the Efficiency LSC energy and LSC energy from the photovoltaic system, battery energy storage systems (BESS), and demand flexibility. 2. Source energy. The source energy budget is determined by applying the mandatory and prescriptive requirements of the standard design, except with a consumer gas or propane water heater, to the proposed design building.

    Exception to Section 170.1(a): A community shared solar electric generation system, or other renewable electric generation system, and/or community shared BESS, that provides dedicated power, utility energy reduction credits or payments for energy bill reductions to the permitted building and is approved by the Energy Commission as specified in Title 24, Part 1, Section 10-115, may offset part or all of the solar electric generation system or BESS LSC energy required to comply with the standards, as calculated according to methods established by the Commission in the Nonresidential ACM Reference Manual.

    (b) Compliance demonstration requirements for performance standards.

    1. Certificate of Compliance and Application for a Building Permit. The application for a building permit shall include documentation pursuant to Sections 10-103(a)1 and 10-103(a)2 that demonstrates, using an approved calculation method, that the building has been designed so that its source energy and LSC energy consumption do not exceed the standard design energy budgets for the applicable climate zone.
    2. Field verification of individual dwelling unit systems. When performance of installed features, materials, components, manufactured devices or systems above the minimum specified in Section 170.2 is necessary for the building to comply with Section 170.1, or is necessary to achieve a more stringent local ordinance, field verification shall be performed in accordance with the applicable requirements in the following subsections, and the results of the verification(s) shall be documented on applicable Certificates of Installation pursuant to Section 10-103(a)3 and applicable Certificates of Verification pursuant to Section 10-103(a)5. A. EER2/SEER2/CEER/HSPF2 Rating. When performance compliance requires installation of a space-conditioning system with a rating that is greater than the minimum rating required by Table 170.2-K or specified for the standard

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    design, the installed system shall be field verified in accordance with the procedures specified in the applicable sections of Reference Residential Appendix RA3. B. Variable capacity heat pump (VCHP) compliance option. When performance compliance requires installation of a heat pump system that meets all the requirements of the VCHP compliance option specified in the ACM Reference Manual, the system shall be field verified in accordance with the procedures in Reference Residential Appendix RA3.4.4.3.

    C. Low leakage air handler. When performance compliance requires installation of a low leakage air-handling unit, the installed air handling unit shall be field verified in accordance with the procedures specified in Reference Residential Appendix RA3.1.4.3.9. D. Thermal balancing valve. When performance compliance requires installation of thermal balancing valves with variable speed circulation pump(s), the installation shall meet the procedures specified in Reference Residential Appendix RA4.4.3. E. Heat pump—rated heating capacity.

  • § 170.0 High relevance — show source text

    Exception to Section 170.0 (a)3: If a single development falls in more than one climate zone, all buildings in the subdivision or tract may be designed to meet the performance or prescriptive standards for the climate zone that contains 50 percent or more of the dwelling units.

    NOTE: The Commission periodically updates, publishes and makes available to interested persons and local enforcement agencies precise descriptions of the climate zones, as specified in Reference Joint Appendix JA2—Weather/Climate Data.

    NOTE: The requirements of Sections 170.1(a) through 170.2(e) apply to newly constructed buildings and Sections 180.1 and 180.2 specify changes to the requirements of Sections 170.1(a) through 170.2(e) that apply to additions or alterations.

    NOTE: Authority: Sections 25213, 25218, 25218.5, 25402 and 25402.1, Public Resources Code . Reference: Sections 25007, 25008, 25218.5, 25310, 25402, 25402.1, 25402.4, 25402.5, 25402.8 and 25943, Public Resources Code .

    SECTION 170.1—PERFORMANCE APPROACH

    A building complies with the performance approach if the energy consumption calculated for the proposed design building is no greater than the energy budget calculated for the standard design building using Commission-certified compliance software as specified by Sections 10-109 and 10-116 and the Alternative Calculation Method Reference Manual.

    (a) Energy budget. The energy budget is expressed in terms of long-term system cost (LSC) and source energy:

    1. Long-term system cost (LSC). The LSC energy budget is determined by applying the mandatory and prescriptive requirements of the standard design to the proposed design building and has two components, the Efficiency LSC and the Total LSC.

    A. The Efficiency LSC energy is the sum of the LSC energy for space-conditioning, water heating, mechanical ventilation, lighting and the self-utilization credit. B. The Total LSC energy is the sum of the Efficiency LSC energy and LSC energy from the photovoltaic system, battery energy storage systems (BESS), and demand flexibility. 2. Source energy. The source energy budget is determined by applying the mandatory and prescriptive requirements of the standard design, except with a consumer gas or propane water heater, to the proposed design building.

    Exception to Section 170.1(a): A community shared solar electric generation system, or other renewable electric generation system, and/or community shared BESS, that provides dedicated power, utility energy reduction credits or payments for energy bill reductions to the permitted building and is approved by the Energy Commission as specified in Title 24, Part 1, Section 10-115, may offset part or all of the solar electric generation system or BESS LSC energy required to comply with the standards, as calculated according to methods established by the Commission in the Nonresidential ACM Reference Manual.

    (b) Compliance demonstration requirements for performance standards.

    1. Certificate of Compliance and Application for a Building Permit. The application for a building permit shall include documentation pursuant to Sections 10-103(a)1 and 10-103(a)2 that demonstrates, using an approved calculation method, that the building has been designed so that its source energy and LSC energy consumption do not exceed the standard design energy budgets for the applicable climate zone.
    2. Field verification of individual dwelling unit systems.
  • § 140.0 High relevance — show source text

    Note to Section 140.0(c): The Commission periodically updates, publishes and makes available to interested persons and local enforcement agencies precise descriptions of the climate zones, which is available by zip code boundaries depicted in the Reference Joint Appendices along with a list of the communities in each zone.

    Note to Section 140.0: The requirements of Sections 140.1 through 140.10 apply to newly constructed buildings. Section 141.0 specifies which requirements of Sections 140.1 through 140.10 also apply to additions or alterations to existing buildings.

    Note: Authority: Sections 25213, 25218, 25218.5, 25402 and 25402.1, Public Resources Code. Reference: Sections 25007, 25008, 25218.5, 25310, 25402, 25402.1, 25402.4, 25402.5, 25402.8, and 25943, Public Resources Code.

    SECTION 140.1—PERFORMANCE APPROACH: ENERGY BUDGETS

    A building complies with the performance standards if the energy consumption calculated for the proposed design building is no greater than the energy budget calculated for the standard design building using Commission-certified compliance software as specified by Sections 10-109(c) and 10-116.

    (a) Energy budget. The energy budget is expressed in terms of long-term system cost (LSC) and source energy.

    1. Long-term system cost (LSC). The LSC energy budget is determined by applying the mandatory and prescriptive requirements of the standard design to the proposed design building and has two components, the Efficiency LSC and the Total LSC.

    A. The Efficiency LSC energy is the sum of the LSC energy for space-conditioning, water heating, mechanical ventilation, and lighting. B. The Total LSC energy is the sum of the Efficiency LSC energy and LSC energy from the photovoltaic system, battery energy storage systems (BESS) and demand flexibility. 2. Source energy . The source energy budget is determined by applying the mandatory and prescriptive requirements of the standard design to the proposed design building.

    Exception to Section 140.1(a). A community shared solar electric generation system, or other renewable electric generation system, and/or community shared BESS, that provides dedicated power, utility energy reduction credits or payments for energy bill reductions to the permitted building and is approved by the Energy Commission as specified in Title 24, Part 1, Section 10-115, may offset part or all of the solar electric generation system or BESS LSC energy required to comply with the standards, as calculated according to methods established by the Commission in the Nonresidential ACM Reference Manual.

    Note: Authority: Sections 25213, 25218, 25218.5, 25402 and 25402.1, Public Resources Code. Reference: Sections 25007, 25008, 25218.5, 25310, 25402, 25402.1, 25402.4, 25402.5, 25402.8, and 25943, Public Resources Code.

    SECTION 140.2—PRESCRIPTIVE APPROACH

    To comply using the prescriptive approach a building shall be designed with and shall have constructed and installed systems and components meeting the applicable requirements of Sections 140.3 through 140.10.

  • § 170.2 High relevance — show source text

    The rated energy capacity shall be not less than the Minimum Rated Useable Energy Capacity determined by Equation 170.2-E, or by Equation 170.2-F if SARA was used to determine the PV capacity in Section 170.2-D, and the rated power capacity shall be not less than the Minimum Power Capacity determined by Equation 170.2-G. In mixed occupancy buildings, the total battery system capacity for the building shall be determined by applying the Minimum Rated Usable Energy Capacity to each of the listed building types and summing the capacities determined for each.

    EQUATION 170.2-E—BATTERY ENERGY STORAGE SYSTEM MINIMUM RATED USABLE ENERGY CAPACITY kWh batt = k((CFA × B)/(1000 × C [0.5] ))

    — EQUATION 170.2-F BATTERY ENERGY STORAGE SYSTEM MINIMUM RATED USABLE ENERGY CAPACITY, SARA-ADJUSTED kWh batt = k((CFA × B)/(1000 × C [0.5] )) × (kWP Vdc,SARA /kWP Vdc )

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    where:

    kWh batt = Minimum Rated Usable Energy Capacity of the BESS in kWh.

    kW PVdc = Minimum Rated PV System Capacity in kW from Equation 170.2D. kW PVdc, SARA = Minimum Rated PV System Capacity in kW from the SARA calculation. CFA = Conditioned floor area that is subject to the PV system requirements of Section 170.2(g) in square feet.

    B = BESS Capacity Factor in Wh/square foot as specified in Table 170.2-V for the building type.

    C = Rated single charge-discharge cycle AC to AC (round-trip) efficiency of the BESS.

    EQUATION 170.2-G—BATTERY ENERGY STORAGE SYSTEM MINIMUM RATED POWER CAPACITY

    kW batt = kW batt /4

    where:

    kW batt = Minimum Rated Power Capacity of the BESS in kW dc .

    kWh batt = Minimum Rated Usable Energy Capacity of the BESS in kWh.

    Exception 1 to Section 170.2(h): No BESS is required if the installed PV system capacity is less than 15 percent of the capacity determined by Equation 170.2-D.

    Exception 2 to Section 170.2(h): No BESS is required in buildings with BESS requirements with less than 10 kWh minimum rated usable energy capacity.

    |TABLE 170.

  • § 140.10 High relevance — show source text

    Exception 1 to Section 140.10(a): No PV system is required where the total of all available SARA is less than 3 percent of the conditioned floor area.

    Exception 2 to Section 140.10(a): No PV system is required where the required PV system capacity is less than 4 kW dc .

    Exception 3 to Section 140.10(a): No PV system is required if the SARA contains less than 80 contiguous square feet.

    Exception 4 to Section 140.10(a): Buildings with enforcement-authority-approved roof designs, where the enforcement authority determines it is not possible for the PV system, including panels, modules, components, supports and attachments to the roof structure, to meet ASCE 7-16, Chapter 7, Snow Loads.

    Exception 5 to Section 140.10(a): For nonresidential and hotel/motel multitenant buildings, the PV capacity determined by Equation 140.10-A shall be calculated without including tenant spaces meeting all of the following: i. The tenant space is less than or equal to 2,000 square feet of conditioned space; ii. The tenant space is served by an HVAC system that does not serve other tenant spaces in the building; and iii. The tenant space has an individual utility meter to track electricity consumption that does not include the electricity consumption of other tenant spaces in the building.

    This exception does not apply where the Commission has approved a community solar program for showing compliance as specified in Title 24, Part 1, Section 10-115, or where a load-serving entity provides a program where PV generation is compensated through virtual energy bill credits for occupants of nonresidential and hotel/motel tenant spaces to receive energy bill benefits from netting of energy generation and consumption.

    (b) Battery energy storage system (BESS) requirements. All buildings that are required by Section 140.10(a) to have a PV system shall also have a BESS meeting the minimum qualification requirements of Reference Joint Appendix JA12. The rated energy capacity shall be not less than the Minimum Rated Useable Energy Capacity determined using Equation 140.10-B or 140.10-C if SARA was used to determine the PV capacity in Section 140.10(a). The rated power capacity shall be not less than the Minimum Power Capacity determined using Equation 140.10-D. In mixed occupancy buildings, the total battery system capacity for the building shall be determined by applying the Minimum Rated Usable Energy Capacity to each of the listed building types and summing the capacities determined for each.

    EQUATION 140.10-B—BATTERY ENERGY STORAGE SYSTEM MINIMUM RATED USABLE ENERGY CAPACITY kWh batt = [(CFA × B)/(1,000 × C [0.5] )]

    EQUATION 140.10-C—BATTERY ENERGY STORAGE SYSTEM MINIMUM RATED USABLE ENERGY CAPACITY, SARA-ADJUSTED kWh batt = [(CFA × B)/(1,000 × C [0.5] )] x (kW PVdc,SARA /kW PVdc )

    where:

    kWh batt = Minimum Rated Usable Energy Capacity of the BESS in kWh.

    CFA = Conditioned floor area that is subject to the PV system requirements of Section 140.10(a) in square feet.

  • § 203.1.1 High relevance — show source text

    A4.203.1.1 Long-term system cost (LSC). LSC rating for the building’s Proposed Design shall be computed by Compliance Software certified by the Energy Commission as specified in Title 24, Part 6, Section 100.1 and 150.1(b), and shall reduce the LSC required in the Compliance Software for minimum performance-based compliance with the California Energy Code by the compliance margin specified in Table A4.203.1.1. The rating shall be included in the Certificate of Compliance documentation.

    TABLE A4.203.1.1—RECOMMENDED LSC MARGINS BY CLIMATE ZONES Col2
    CALIFORNIA ENERGY CODE CLIMATE ZONE TOTAL LSC COMPLIANCE MARGIN
    1 2.70
    2 1.62
    3 1.10
    4 1.11
    5 1.01
    6 0.24
    7 0.24
    8 0.21
    9 0.20
    10 0.18
    11 1.11
    12 1.05
    13 0.96
    14 1.21
    15 0.59
    16 1.68
    Note: Community shared options complying with Title 24, Part 1, Section 10-115 may be used to achieve LSC targets. Note: Community shared options complying with Title 24, Part 1, Section 10-115 may be used to achieve LSC targets.

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    APPENDIX A4 — RESIDENTIAL VOLUNTARY MEASURES

    A4.203.1.2 Prerequisite options. In addition, a minimum of TWO of the efficiency measures specified in Sections A4.203.1.2.1 through A4.203.1.2.7 must be met.

    A4.203.1.2.1 Roof deck insulation, or ducts in conditioned space. Meet one of the three options for the location of ducts and air handlers as well as insulation R -values and installation of a radiant barrier as specified in Title 24, Part 6, Section 150.1(c)9A or B:

    1. Below roof deck insulation with a minimum R -value of 19; or,

    2. Continuous above deck insulation with a minimum R-8 and with an air space present between the roofing and the roof deck; or,

    3. All ducts and air handlers in conditioned space as specified in the Title 24, Part 6, Reference Appendix RA3.1.

    A4.203.1.2.2 High performance walls. Meet the climate zone dependent U -factor or insulation R -value for either 2x6 or 2x4 framing as specified in Title 24, Part 6, Section 150.1(c)1B: maximum U -factor of 0.048.

    A4.203.1.2.3 Compact hot water distribution system. Meet the requirements for installation of Compact Hot Water Distribution Systems specified in the Title 24, Part 6, Reference Appendix RA3.6.5.

  • § 150.1 High relevance — show source text

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    8 SINGLE-FAMILY RESIDENTIAL BUILDINGS—PERFORMANCE

    AND PRESCRIPTIVE COMPLIANCE APPROACHES

    SECTION 150.1—PERFORMANCE AND PRESCRIPTIVE COMPLIANCE APPROACHES FOR SINGLE-FAMILY RESIDENTIAL BUILDINGS

    (a) Basic requirements. Single-family residential buildings shall meet all of the following:

    1. The applicable requirements of Sections 110.0 through 110.10.
    2. The applicable requirements of Section 150.0 (mandatory features).
    3. Either the performance standards or the prescriptive standards set forth in this section for the climate zone in which the building is located. Climate zones are shown in Reference Joint Appendix JA2–Weather/Climate Data. Exception to Section 150.1(a)3: If a single contiguous subdivision or tract falls in more than one climate zone, all buildings in the subdivision or tract may be designed to meet the performance or prescriptive standards for the climate zone that contains 50 percent or more of the dwelling units. Note: The Commission periodically updates, publishes, and makes available to interested persons and local enforcement agencies precise descriptions of the climate zones, as specified in Reference Joint Appendix JA2–Weather/Climate Data.

    Note: The requirements of Sections 150.0(a) through 150.0(r) apply to newly constructed buildings and Sections 150.2(a) and 150.2(b) specifies changes to the requirements of Sections 150.1(a) through 150.1(c) that apply to additions or alterations.

    (b) Performance approach. A building complies with the performance approach if the energy consumption calculated for the proposed design building is no greater than the energy budget calculated for the standard design building using Commission-certified compliance software as specified by Sections 10-109(c) and 10-116.

    1. Energy budget. The energy budget is expressed in terms of source energy and long-term system cost (LSC). A. Long-term system cost (LSC). The LSC energy budget is determined by applying the mandatory and prescriptive requirements of the standard design to the proposed design building and has two components, the Efficiency LSC and the Total LSC.

    i. The Efficiency LSC energy is the sum of the LSC energy for space-conditioning, water heating, mechanical ventilation, and the self-utilization credit.

    ii. The Total LSC energy is the sum of the Efficiency LSC energy and LSC energy from the photovoltaic system, battery energy storage systems (BESS), lighting, demand flexibility, and other plug loads. B. Source energy. The source energy budget is determined by applying the mandatory and prescriptive requirements of the standard design to the proposed design building. The source energy is the total annual source energy. Exception to Section 150.1(b)1. A community shared solar electric generation system, or other renewable electric generation system, or community shared BESS, which provides dedicated power, utility energy reduction credits, or payments for energy bill reductions to the permitted building and is approved by the Energy Commission as specified in Title 24, Part 1, Section 10-115, may offset part or all of the solar electric generation system and demand flexibility Energy Design Rating required to comply with the Standards, as calculated according to methods established by the Commission in the Residential ACM Reference Manual.

  • § 10-109 High relevance — show source text

    (b) Performance approach. A building complies with the performance approach if the energy consumption calculated for the proposed design building is no greater than the energy budget calculated for the standard design building using Commission-certified compliance software as specified by Sections 10-109(c) and 10-116.

    1. Energy budget. The energy budget is expressed in terms of source energy and long-term system cost (LSC). A. Long-term system cost (LSC). The LSC energy budget is determined by applying the mandatory and prescriptive requirements of the standard design to the proposed design building and has two components, the Efficiency LSC and the Total LSC.

    i. The Efficiency LSC energy is the sum of the LSC energy for space-conditioning, water heating, mechanical ventilation, and the self-utilization credit.

    ii. The Total LSC energy is the sum of the Efficiency LSC energy and LSC energy from the photovoltaic system, battery energy storage systems (BESS), lighting, demand flexibility, and other plug loads. B. Source energy. The source energy budget is determined by applying the mandatory and prescriptive requirements of the standard design to the proposed design building. The source energy is the total annual source energy. Exception to Section 150.1(b)1. A community shared solar electric generation system, or other renewable electric generation system, or community shared BESS, which provides dedicated power, utility energy reduction credits, or payments for energy bill reductions to the permitted building and is approved by the Energy Commission as specified in Title 24, Part 1, Section 10-115, may offset part or all of the solar electric generation system and demand flexibility Energy Design Rating required to comply with the Standards, as calculated according to methods established by the Commission in the Residential ACM Reference Manual.

    1. Compliance demonstration requirements for performance standards. A. Certificate of compliance and application for a building permit. The application for a building permit shall include documentation pursuant to Sections 10-103(a)1 and 10-103(a)2 which demonstrates, using an approved calculation method, that the building has been designed so that its energy consumption does not exceed the standard design energy budgets for the applicable climate zone. Exception to Section 150.1(b)2A Multiple orientation: A permit applicant may demonstrate compliance with the energy budget requirements of Section 150.1(a) and (b) for any orientation of the same building model if the documentation demonstrates that the building model with its proposed designs and features would comply in each of the four cardinal orientations.

    B. Field verification. When performance of installed features, materials, components, manufactured devices or systems above the minimum specified in Section 150.1(c) is necessary for the building to comply with Section 150.1(b), or is necessary to achieve a more stringent local ordinance, field verification shall be performed in accordance with the applicable requirements in the following subsections, and the results of the verification(s) shall be documented on applicable certificates of installation pursuant to Section 10-103(a)3 and applicable certificates of verification pursuant to Section 10-103(a)5. i. EER2/SEER2/CEER/HSPF2 Rating. When performance compliance requires installation of a space-conditioning system with a rating that is greater than the minimum rating required by Table 150.1-A or specified for the standard design, the installed system shall be field verified in accordance with the procedures specified in the applicable sections of Reference Residential Appendix RA3.4. ii. **Variable capacity heat pump (VCHP) compliance option.

  • § 201.1 High relevance — show source text

    SECTION A4.201—GENERAL

    A4.201.1 Scope. For the purposes of mandatory energy efficiency standards in the California Building Standards Code (Title 24), the California Energy Commission will continue to adopt mandatory standards in the California Energy Code (Title 24, Part 6). It is the intent of these voluntary provisions to encourage local jurisdictions through codification to achieve exemplary performance in the area of building energy efficiency. Local jurisdictions adopting these voluntary provisions as mandatory local energy efficiency standards shall submit the required application and receive the required approval of the California Energy Commission in compliance with Title 24, Part 1, Section 10-106 prior to enforcement. Once the required filing has been verified and finding has been made by the Energy Commission, local jurisdictions shall file an ordinance expressly marking the local modification along with findings and receive the required acceptance from the California Building Standards Commission in compliance with Section 101.7 of this code, prior to enforcement. (Title 24, Part 1, Section 10-106 is available at https://www.energy.ca.gov/programs-and-topics/programs/build- ing-energy-efficiency-standards/2025-building-energy-efficiency

    SECTION A4.202—DEFINITIONS

    A4.202.1 Definitions. The following terms are defined in Chapter 2.

    ENERGY BUDGET.

    LONG-TERM SYSTEM COST (LSC).

    RECOVERED ENERGY, ON-SITE.

    SOLAR POOL HEATING SYSTEM.

    SECTION A4.203—PERFORMANCE APPROACH FOR NEWLY CONSTRUCTED BUILDINGS

    A4.203.1 Energy efficiency. Newly constructed low-rise residential buildings shall comply with Sections A4.203.1.1 through A4.203.1.4.

    A4.203.1.1 Long-term system cost (LSC). LSC rating for the building’s Proposed Design shall be computed by Compliance Software certified by the Energy Commission as specified in Title 24, Part 6, Section 100.1 and 150.1(b), and shall reduce the LSC required in the Compliance Software for minimum performance-based compliance with the California Energy Code by the compliance margin specified in Table A4.203.1.1. The rating shall be included in the Certificate of Compliance documentation.

    TABLE A4.203.1.1—RECOMMENDED LSC MARGINS BY CLIMATE ZONES Col2
    CALIFORNIA ENERGY CODE CLIMATE ZONE TOTAL LSC COMPLIANCE MARGIN
    1 2.70
    2 1.62
    3 1.10
    4 1.11
    5 1.01
    6 0.24
    7 0.24
    8 0.21
    9 0.20
    10 0.18
    11 1.11
    12 1.05
    13 0.96
    14 1.21
    15 0.59
    16 1.68
    Note: Community shared options complying with Title 24, Part 1, Section 10-115 may be used to achieve LSC targets. Note: Community shared options complying with Title 24, Part 1, Section 10-115 may be used to achieve LSC targets.

    2025 CALIFORNIA GREEN BUILDING STANDARDS CODE APPENDIX A4-9

  • § 150.1 High relevance — show source text

    where:

    kW PV = kW dc size of the PV system.

    CFA = Conditioned floor area.

    N DU = Number of dwelling units. A = CFA adjustment factor from Table 150.1-C. B = Dwelling unit adjustment factor from Table 150.1-C. Exception 1 to Section 150.1(c)14: For steep slope roofs, SARA shall not consider roof areas with a northerly azimuth that lies between 300 degrees and 90 degrees from true north. No PV system is required if the SARA is less than 80 contiguous square feet. Exception 2 to Section 150.1(c)14: No PV system is required when the minimum PV system size specified by Section 150.1(c)14 is less than 1.8 kW dc . Exception 3 to Section 150.1(c)14: Buildings with enforcement-authority-approved roof designs, where the enforcement authority determines it is not possible for the PV system, including panels, modules and components and supports and attachments to the roof structure, to meet the requirements of the American Society of Civil Engineers (ASCE), Standard 7-16, Chapter 7, Snow Loads. Exception 4 to Section 150.1(c)14: For buildings that are approved by the local planning department prior to January 1, 2020 with mandatory conditions for approval: a. Shading from roof designs and configurations for steep-sloped roofs, which are required by the mandatory conditions for approval, shall be considered for the annual solar access calculations; and b. Roof areas that are not allowed by the mandatory conditions for approval to have PVs shall not be considered in determining the SARA. Exception 5 to Section 150.1(c)14: PV system sizes determined using Equation 150.1-C may be reduced by 25 percent if installed in conjunction with a BESS. The BESS shall meet the qualification requirements specified in Joint Appendix JA12 and have a minimum cycling capacity of 7.5 kWh as defined in Joint Appendix JA12. 15. Ventilation system fault indicator display (FID): All HRV/ERV systems serving individual dwelling units shall have a fault indicator display (FID) that is ECC-Rater field verified as specified in Joint Appendix JA17.

    182 2025 CALIFORNIA ENERGY CODE

    on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.

    SINGLE-FAMILY RESIDENTIAL BUILDINGS—PERFORMANCE AND PRESCRIPTIVE COMPLIANCE APPROACHES

    |TABLE 150.

  • § 170.2 High relevance — show source text

    EQUATION 170.2-C—ANNUAL PHOTOVOLTAIC ELECTRICAL OUTPUT

    kW PV = (CFA × A)/1000 + N DU × B)

    where:

    kW PV = kW dc size of the PV system.

    CFA = Conditioned floor area.

    266 2025 CALIFORNIA ENERGY CODE

    on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.

    MULTIFAMILY BUILDINGS—PERFORMANCE AND PRESCRIPTIVE COMPLIANCE APPROACHES

    N DU = Number of dwelling units.

    A = CFA adjustment factor from Table 170.2-T.

    B = Dwelling unit adjustment factor from Table 170.2-T.

    Exception 1 to Section 170.2(f): For steep slope roofs, SARA shall not consider roof areas with a northerly azimuth that lies between 300 degrees and 90 degrees from true north. No PV system is required if the SARA is less than 80 contiguous square feet.

    Exception 2 to Section 170.2(f): No PV system is required when the minimum PV system size specified by Section 170.2(f) is less than 4 kW dc .

    Exception 3 to Section 170.2(f): Buildings with enforcement-authority-approved roof designs, where the enforcement authority determines it is not possible for the PV system, including panels, modules and components and supports and attachments to the roof structure, to meet the requirements of American Society of Civil Engineers (ASCE) Standard 7-16, Chapter 7, Snow Loads.

    Exception 4 to Section 170.2(f): For buildings that are approved by the local planning department prior to January 1, 2020 with mandatory conditions of approval: a. Shading from roof designs and configurations for steep slope roofs shall be considered for the annual solar access calculations; and

    b. Roof areas that are not allowed to have PVs by the mandatory conditions of approval shall not be considered in determining the SARA.

    Exception 5 to Section 170.2(f): PV system sizes determined using Equation 170.2-C may be reduced by 25 percent if installed in conjunction with a BESS. The BESS shall meet the qualification requirements specified in Joint Appendix JA12 and have a minimum cycling capacity of 7.5 kWh as defined in Joint Appendix JA12.

    TABLE 170.2-T—CFA AND DWELLING UNIT ADJUSTMENT FACTORS Col2 Col3
    CLIMATE ZONE A—CFA B—DWELLING UNITS
    1 0.793 1.27
    2 0.621 1.22
    3 0.628 1.12
    4 0.586 1.21
    5 0.585 1.06
    6 0.594 1.23
    7 0.572 1.15
    8 0.586 1.37
    9 0.613 1.36
    10 0.627 1.41
    11 0.836 1.44
    12 0.613 1.40
    13 0.894 1.51
    14 0.741 1.26
    15 1.56 1.47
    16 0.59 1.22

    (g) **Photovoltaic requirements—more than three habitable stories.

Frequently asked questions

Can any community solar program be used to offset my building’s PV/BESS requirement?

No. Only programs approved by the Energy Commission under Title 24, Part 1, § 10‑115 may be used for code compliance offsets. The Exception language in § 170.1(a) and § 140.1(a) requires that approval.

How do I show the offset on my permit application?

Include the ACM calculation demonstrating the offset in your Certificate of Compliance and permit application per § 170.1(b)1, and include the Energy Commission program approval documentation (per § 10‑115).

Do offsets apply to prescriptive compliance?

The community/shared offset language is tied to the performance approach LSC budget (see § 140.1, § 170.1, and residential § 150.1). Prescriptive pathways have their own exceptions and calculations; you must use the performance/ACM path to apply shared offsets.

Does a shared BESS always eliminate the need for any on‑site BESS?

Not automatically. The amount a shared BESS can offset is determined by the Commission’s ACM method for translating program benefits into LSC energy credits; the ACM calculation — not a blanket rule — controls how much (if any) of the required BESS LSC is offset.

Where are the exact math and procedures published?

The Code requires use of the Commission’s ACM Reference Manual (Residential or Nonresidential as applicable) for the offset calculations; consult that manual and the certified compliance software for the exact procedures. § 170.1(a) and the Exception language reference those ACM methods.

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