Title 24 · California Energy Code
What product qualification (JA11/JA12) and installation standards apply to PV and BESS
If your new building is covered by §140.10, the Energy Code requires PV equipment that meets Joint Appendix JA11 and, where required, a BESS that meets Joint Appendix JA12. PV and BESS sizes are set by the code’s equations (use Table 140.10‑A for PV factors and Table 140.10‑B for BESS factors); a few explicit exceptions (small PV area, small PV system, or tiny calculated BESS capacity) can remove the obligation.
Last reviewed: July 6, 2026
What the code requires — plain English
- Newly constructed buildings listed in Table 140.10-A that must install photovoltaics (PV) must use PV products that meet the minimum product qualification requirements in Reference Joint Appendix JA11 as required by § 140.10(a).
- Buildings that are required to have PV under § 140.10(a) must also install a battery energy storage system (BESS) that meets the minimum product qualification requirements of Reference Joint Appendix JA12, sized by the code’s BESS equations for minimum usable energy and minimum power capacity in § 140.10(b).
The single most important rule: PV equipment must be JA11‑qualified and BESS equipment must be JA12‑qualified where the code requires them — sizing follows the code’s equations in § 140.10(a) and § 140.10(b).
Requirements in detail
Product qualification (what “JA11 / JA12” means)
- PV product qualification = Joint Appendix JA11. Where § 140.10(a) requires a PV system, the installed PV system or modules must meet the minimum qualification requirements in JA11. § 140.10(a) requires that qualification.
- BESS product qualification = Joint Appendix JA12. Where § 140.10(b) requires a BESS, the BESS must meet the minimum qualification requirements in JA12. § 140.10(b) requires that qualification.
(See the referenced Joint Appendices themselves for the specific testing, listing/certification, labeling, installation documentation, and commissioning checks required by JA11 and JA12 — the Energy Code text points you to those appendices as the qualification standards.)
Sizing rules (what the code requires you to calculate)
- PV minimum rated DC capacity: use Equation 140.10‑A: kW PVdc = (CFA × A) / 1000, or use the SARA-based cap (SARA × 18 for steep roofs; SARA × 14 for low‑sloped roofs) — take the smaller value. This sizing rule is in § 140.10(a).
- BESS minimum usable energy capacity: use Equation 140.10‑B (or 140.10‑C when the SARA adjustment is used):
kWh batt = [(CFA × B) / (1,000 × C[0.5])] (and multiply by kW PVdc,SARA / kW PVdc when SARA is used). These are required by § 140.10(b).- B = BESS capacity factor (Wh/ft²) from Table 140.10‑B (by building type and climate zone).
- C = round‑trip efficiency (AC-to-AC) of the BESS (manufacturer rating).
- BESS minimum rated power capacity: use Equation 140.10‑D (minimum power ≈ energy ÷ 4). This is specified in § 140.10(b).
Installation / interoperability and related prescriptive notes
- Where the code allows a reduction in PV size when a BESS is installed (in some residential and multifamily sections), that reduction requires the installed BESS to meet JA12 and a stated minimum cycling capacity (for example, 7.5 kWh in other sections that permit a 25% PV reduction when a BESS is present). See referenced residential/multifamily sections.
Decision‑relevant table (quick reference)
| Dimension / Threshold | Required value(s) | Code reference |
|---|---|---|
| PV product qualification | Must meet JA11 | § 140.10(a) |
| PV sizing (equation) | kW PVdc = (CFA × A)/1000 OR SARA × 18 (steep) / × 14 (low) — take smaller | § 140.10(a); Equation 140.10‑A |
| PV SARA exclusions/limits | SARA < 3% of CFA → no PV required; SARA < 80 sq ft → no PV required; min PV capacity threshold 4 kWdc exception | Exceptions to § 140.10(a) |
| BESS product qualification | Must meet JA12 | § 140.10(b) |
| BESS usable energy sizing | kWh batt = [(CFA × B)/(1,000 × C[0.5])] (SARA‑adjusted uses Eq 140.10‑C) | Equation 140.10‑B / 140.10‑C in § 140.10(b) |
| BESS power sizing | Minimum kW ≈ (kWh batt) / 4 | Equation 140.10‑D in § 140.10(b) |
| BESS exceptions | No BESS if installed PV < 15% of Equation 140.10‑A capacity; or if calculated kWh batt < 10 kWh; multitenant rules apply | Exceptions to § 140.10(b) |
| PV size reduction when paired with BESS (other sections) | Some sections permit 25% PV reduction if BESS meets JA12 and min cycling capacity 7.5 kWh | See § 150.1(c)14 / § 170.2(f) exceptions |
Exceptions & special cases
- No PV required if total available SARA is less than 3% of conditioned floor area (Exception 1 to § 140.10(a)).
- No PV required if the required PV capacity is less than 4 kWdc (Exception 2 to § 140.10(a)).
- No PV required if SARA contains less than 80 contiguous sq ft (Exception 3 to § 140.10(a)).
- No BESS required if installed PV capacity is less than 15% of the capacity computed by Equation 140.10‑A (Exception 1 to § 140.10(b)).
- No BESS required if the computed minimum usable energy (Eq. 140.10‑B or C) is less than 10 kWh (Exception 2 to § 140.10(b)).
- Multitenant and mixed‑occupancy rules: PV and BESS capacities are computed by applying the equations to each listed building type’s conditioned floor area and summing; for multitenant BESS sizing rules apply only to tenant spaces over 5,000 sq ft in some cases (Exception 3 to § 140.10(b)).
Common mistakes
- Treating JA11/JA12 as optional product guidance rather than the mandatory qualification reference when the section requires PV/BESS. The code explicitly requires JA11 for PV and JA12 for BESS where § 140.10(a)/(b) applies.
- Using the SARA roof area without checking the code’s exclusions (70% annual solar access, occupied roofs, local/state conflicts) — SARA has specific exclusions in § 140.10(a).
- Forgetting to apply the exceptions thresholds (4 kWdc, 3% SARA, 80 ft², 15% PV threshold for BESS) which may remove an obligation entirely.
- Misreading Equation 140.10‑D: the code states minimum power approximately equals the minimum energy capacity divided by 4 (i.e., kW ≈ kWh / 4). Use the exact equation as written in § 140.10(b).
- Assuming any product labeled “for grid‑tie” meets JA11/JA12 — you must verify the product meets the specific JA11/JA12 qualification (listing/certs) referenced by the code.
Worked example — how to apply the rules (concrete)
Example scope: new office building, conditioned floor area (CFA) = 20,000 ft², Climate Zone 2.
Compute minimum PV capacity (Equation 140.10‑A). From Table 140.10‑A, the PV capacity factor A for Office, CZ 2 is 3.13 W/ft². Use § 140.10(a) and Equation 140.10‑A.
kW PVdc = (CFA × A) / 1000 = (20,000 ft² × 3.13 W/ft²) / 1000 = 62.6 kWdc.
Check SARA alternative: if SARA available roof area × 18 (steep) or × 14 (low) yields a smaller number, use that smaller number instead per § 140.10(a).
Is a BESS required? Yes, because the building is required to have PV under § 140.10(a), so § 140.10(b) requires a BESS that meets JA12 — subject to the BESS exceptions (see below).
Compute minimum BESS usable energy (Equation 140.10‑B). The equation needs the BESS capacity factor B from Table 140.10‑B (by building type and climate zone) and the BESS round‑trip efficiency C (manufacturer spec): kWh batt = [(CFA × B)/(1,000 × C[0.5])]. See § 140.10(b).
NOTE: In the files provided I can show the Equation and that B is found in Table 140.10‑B (by building type & CZ), but I could not extract the exact B value for Office/CZ2 from the retrieved snippets. You must look up Table 140.10‑B in your copy of the code or the referenced tables to obtain the correct B for this building type and climate zone. The code requires using that tabulated B value in § 140.10(b).
For illustration only (assumption): if B = 2.0 Wh/ft² and C = 0.90, then kWh batt = [(20,000 × 2.0)/(1,000 × 0.90[0.5])] ≈ compute per the code formula. But do not treat this numeric result as code-mandated — replace B with the code table value and C with the manufacturer’s listed efficiency when doing your compliance math.
Compute minimum BESS power (Equation 140.10‑D): kW batt = (kWh batt) / 4 (as specified in § 140.10(b)).
Check BESS exceptions: If the installed PV is less than 15% of the Equation 140.10‑A capacity, or if the computed kWh batt < 10 kWh, a BESS is not required (exceptions in § 140.10(b)). Also apply multitenant rules as specified.
Related provisions
- § 140.10(a) — Photovoltaic requirements (qualification reference to JA11 and sizing equations).
- § 140.10(b) — BESS requirements (qualification reference to JA12 and sizing equations).
- Residential/multifamily analogous rules and PV/BESS reductions: § 150.1(c)14 and § 170.2(f)/(h) (show PV reductions when paired with a JA12 BESS; minimum cycling capacity references).
- Tables used for sizing: Table 140.10‑A (PV capacity factors by building type & CZ) and Table 140.10‑B (BESS capacity factors by building type & CZ) — used directly in equations in § 140.10.
Code references
Grounded in the retrieved California Energy Code — click a citation to read the verbatim passage:
§ 140.10 High relevance — show source text
(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.
kW PVdc = Minimum Rated PV System Capacity in kW from Equation 140.10-A. kW PVdc, SARA = Minimum Rated PV System Capacity in kW from the SARA calculation. B = BESS Capacity Factor in Wh/square foot as specified in Table 140.10-B for the building type. C = Rated single charge-discharge cycle AC to AC (round-trip) efficiency of the BESS.
EQUATION 140.10-D—BESS MINIMUM RATED POWER CAPACITY
kW batt = kW batt /4
where:
kW batt = Minimum Rated Power Capacity of the BESS in kWdc. kW PVdc = Minimum Rated Useable Energy Capacity of the BESS in kWh. Exception 1 to Section 140.10(b): No BESS is required if the installed PV system capacity is less than 15 percent of the capacity determined by Equation 140.10-A.
Exception 2 to Section 140.10(b): No BESS is required if the rated usable energy capacity determined by Equation 140.10-B or Equation 140.10-C is less than 10 kWh.
Exception 3 to Section 140.10(b): For multitenant buildings, the energy capacity of the BESS shall be based on the tenant spaces with more than 5,000 square feet of conditioned floor area. For single-tenant buildings with less than 5,000 square feet of conditioned floor area, no BESS is required.
146 2025 CALIFORNIA ENERGY CODE
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
NONRESIDENTIAL AND HOTEL/MOTEL OCCUPANCIES—PERFORMANCE AND PRESCRIPTIVE
COMPLIANCE APPROACHES FOR ACHIEVING ENERGY EFFICIENCY
|TABLE 140.
§ 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.
§ 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 )
268 2025 CALIFORNIA ENERGY CODE
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
MULTIFAMILY BUILDINGS—PERFORMANCE AND PRESCRIPTIVE COMPLIANCE APPROACHES
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.
§ 170.2 High relevance — show source text
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. All newly constructed building types specified in Table 170.2-U, or mixed occupancy buildings where at least 80 percent of the floor area of the building serves one or more of these building types, shall have a newly installed photovoltaic (PV) system meeting the minimum qualification requirements of Reference Joint Appendix JA11. The PV capacity in kW dc shall not be less than the smaller of the minimum rated PV system capacity determined by Equation 170.2-D, or the total of all available solar access roof areas (SARA) multiplied by 18 for steep-sloped roofs or multiplied by 14 for low-sloped roofs. In mixed occupancy buildings, the minimum rated PV system capacity for the building shall be determined by applying Equation 170.2-D to the conditioned floor area of each of the listed building types and summing the capacities determined for each.
SARA include the area of the building’s roof space capable of structurally supporting a PV system, and the area of all roof space on covered parking areas, carports and all other newly constructed structures on the site that are compatible with supporting a PV system per Title 24, Part 2, Section 1511.10.
SARA does not include:
A. Any area that has less than 70 percent annual solar access. Annual solar access is determined by dividing the total annual solar insolation (accounting for shading obstructions) by the total annual solar insolation if the same areas were unshaded by those obstructions. For all roofs, all obstructions including those that are external to the building,
2025 CALIFORNIA ENERGY CODE 267
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
MULTIFAMILY BUILDINGS—PERFORMANCE AND PRESCRIPTIVE COMPLIANCE APPROACHES
and obstructions that are part of the building design and elevation features, may be considered for the annual solar access calculations.
§ 140.10 High relevance — show source text
EQUATION 140.10-D—BESS MINIMUM RATED POWER CAPACITY
kW batt = kW batt /4
where:
kW batt = Minimum Rated Power Capacity of the BESS in kWdc. kW PVdc = Minimum Rated Useable Energy Capacity of the BESS in kWh. Exception 1 to Section 140.10(b): No BESS is required if the installed PV system capacity is less than 15 percent of the capacity determined by Equation 140.10-A.
Exception 2 to Section 140.10(b): No BESS is required if the rated usable energy capacity determined by Equation 140.10-B or Equation 140.10-C is less than 10 kWh.
Exception 3 to Section 140.10(b): For multitenant buildings, the energy capacity of the BESS shall be based on the tenant spaces with more than 5,000 square feet of conditioned floor area. For single-tenant buildings with less than 5,000 square feet of conditioned floor area, no BESS is required.
146 2025 CALIFORNIA ENERGY CODE
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
NONRESIDENTIAL AND HOTEL/MOTEL OCCUPANCIES—PERFORMANCE AND PRESCRIPTIVE
COMPLIANCE APPROACHES FOR ACHIEVING ENERGY EFFICIENCY
TABLE 140.10-A—PV CAPACITY FACTORS (W/ft2 of conditioned floor area) Col2 Col3 Col4 Col5 Col6 Col7 Col8 Col9 Col10 Col11 Col12 Col13 Col14 Col15 Col16 Col17 BUILDING TYPE CZ 1 CZ 2 CZ 3 CZ 4 CZ 5 CZ 6 CZ 7 CZ 8 CZ 9 CZ 10 CZ 11 CZ 12 CZ 13 ** CZ 14** ** CZ 15** ** CZ 16** Events & Exhibits 3.48 4.28 3.66 4.32 3.77 4.05 4.28 4.83 4.63 4.80 5.04 4.44 4.95 4.36 5.48 3.38 Library 0.39 3.23 2.59 3.25 2.48 2.74 3.04 3.49 3.32 3.69 3.79 3.32 3.79 3.37 4.49 2.84 Hotel/Motel 1.69 1.90 1.66 1.97 1.69 1.87 1.94 2.22 2.09 2.20 2.30 2.05 2.30 2.02 2.72 1.73 Office, Financial
Institution, Unleased
Tenant Space, Medical
Office Building/Clinic2.59 3.13 2.59 3.13 2.59 3.13 3.13 3. § 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.
- 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
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.
§ 0.12 High relevance — show source text
(for1/2″
thick sheathing) 13/4″ long ×
0.12″ dia. (for25/32″ thick
sheathing) galvanized
roofing nails|3″ edges 6″ field| |For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 degree = 0.0175 rad, 1 pound per square foot = 47.8 N/m2, 1 mile per hour = 0.447 m/s.
a. Adhesive attachment of wall sheathing, including Method GB, shall not be permitted in Seismic Design Categories C, D0, D1 and D2.
b. Applies to panels next to garage door opening where supporting gable end wall or roof load only. Shall only be used on one wall of the garage. In Seismic Design Categories D0,
D1 and D2, roof covering dead load shall not exceed 3 psf.
c. Garage openings adjacent to a Method CS-G panel shall be provided with a header in accordance with Table R602.7(1). A full-height clear opening shall not be permitted adja-
cent to a Method CS-G panel.
d. Method CS-SFB does not apply in Seismic Design Categories D0, D1 and D2.
e. Method applies to detached one- and two-family dwellings in Seismic Design Categories D0 through D2 only.|For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 degree = 0.0175 rad, 1 pound per square foot = 47.8 N/m2, 1 mile per hour = 0.447 m/s.
a. Adhesive attachment of wall sheathing, including Method GB, shall not be permitted in Seismic Design Categories C, D0, D1 and D2.
b. Applies to panels next to garage door opening where supporting gable end wall or roof load only. Shall only be used on one wall of the garage. In Seismic Design Categories D0,
D1 and D2, roof covering dead load shall not exceed 3 psf.
c. Garage openings adjacent to a Method CS-G panel shall be provided with a header in accordance with Table R602.7(1). A full-height clear opening shall not be permitted adja-
cent to a Method CS-G panel.
d. Method CS-SFB does not apply in Seismic Design Categories D0, D1 and D2.
e. Method applies to detached one- and two-family dwellings in Seismic Design Categories D0 through D2 only.|For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 degree = 0.0175 rad, 1 pound per square foot = 47.8 N/m2, 1 mile per hour = 0.447 m/s.
a. Adhesive attachment of wall sheathing, including Method GB, shall not be permitted in Seismic Design Categories C, D0, D1 and D2.
b. Applies to panels next to garage door opening where supporting gable end wall or roof load only. Shall only be used on one wall of the garage. In Seismic Design Categories D0,
D1 and D2, roof covering dead load shall not exceed 3 psf.
c. Garage openings adjacent to a Method CS-G panel shall be provided with a header in accordance with Table R602.7(1).§ 170.2 High relevance — show source text
268 2025 CALIFORNIA ENERGY CODE
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
MULTIFAMILY BUILDINGS—PERFORMANCE AND PRESCRIPTIVE COMPLIANCE APPROACHES
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 170.2-V—BESS CAPACITY FACTORS (Wh/ft2 of conditioned floor area) Col2 Col3 Col4 Col5 Col6 Col7 Col8 Col9 Col10 Col11 Col12 Col13 Col14 Col15 Col16 Col17 BUILDING TYPE CZ 1 CZ 2 CZ 3 CZ 4 CZ 5 CZ 6 CZ 7 CZ 8 CZ 9 CZ 10 CZ 11 CZ 12 CZ 13 CZ 14 CZ 15 CZ 16 Event & Exhibit 1.82 1.95 1.74 2.12 1.91 2.13 2.24 2.30 2.36 2.47 2.62 2.16 2.64 2.68 3.22 1.89 Library 0.37 7.17 5.97 6.75 5.64 6.08 6.19 7.13 7.18 7.56 7.17 6.93 6.88 6.81 7.93 6.40 Hotel/Motel 0.86 0.84 0.77 0.92 0.81 0.89 0.90 1.01 1.00 1.11 1.14 0.96 1.18 1.18 1.49 0.85 Office, Financial Institution, § 140.9 High relevance — show source text
- In a jurisdiction where gas heating is allowed.
Exception 4 to Section 140.9(c)6: Buildings with an exhaust air heat recovery system and heat recovery chillers designed to provide at least 40 percent of the peak heating load from exhaust heat recovery.
Exception 5 to Section 140.9(c)6: Exhaust systems requiring wash down systems such as exhaust systems dedicated to perchloric acid fume hoods.
Exception to Section 140.9(c): Healthcare facilities.
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, 25402.8 and 25943, Public Resources Code.
SECTION 140.10—PRESCRIPTIVE REQUIREMENTS FOR PHOTOVOLTAIC AND BATTERY ENERGY STORAGE SYSTEMS
(a) Photovoltaic requirements. All newly constructed building types specified in Table 140.10-A, or mixed occupancy buildings where at least 80 percent of the floor area of the building serves one or more of these building types, shall have a newly installed photovoltaic (PV) system meeting the minimum qualification requirements of Reference Joint Appendix JA11. The PV capacity in kW dc shall not be less than the smaller of the minimum rated PV system capacity determined by Equation 140.10-A, or the total of all available solar access roof areas (SARA) multiplied by 18 for steep-sloped roofs or multiplied by 14 for low-sloped roofs. In mixed occupancy buildings, the minimum rated PV system capacity for the building shall be determined by applying Equation 140.10-A to the conditioned floor area of each of the listed building types and summing the capacities determined for each.
SARA includes the area of the building’s roof space capable of structurally supporting a PV system, and the area of all roof space on covered parking areas, carports and all other newly constructed structures on the site that are compatible with supporting a PV system per Title 24, Part 2, Section 1511.10.
SARA does NOT include:
A. Any area that has less than 70 percent annual solar access. Annual solar access is determined by dividing the total annual solar insolation (accounting for shading obstructions) by the total annual solar insolation if the same areas were unshaded by those obstructions. For all roofs, all obstructions, including those that are external to the building, and obstructions that are part of the building design and elevation features may be considered for the annual solar access calculations.
B. Occupied roofs as specified by CBC Section 503.1.4. C. Roof area that is otherwise not available due to compliance with: i. Other state building code requirements; or ii. Local building code requirements if the local building code requirements are confirmed by the Executive Director.
2025 CALIFORNIA ENERGY CODE 145
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
NONRESIDENTIAL AND HOTEL/MOTEL OCCUPANCIES—PERFORMANCE AND PRESCRIPTIVE
COMPLIANCE APPROACHES FOR ACHIEVING ENERGY EFFICIENCY
EQUATION 140.10-A—PHOTOVOLTAIC DIRECT CURRENT CAPACITY
kW PVdc = (CFA × A)/1000
where:
kW PVdc = Minimum rated PV system capacity in kW.
§ 1.27 High relevance — show source text
63|1.27|1.63|1.27|1.63|1.63|1.63|1.63|1.63|1.63|1.63|1.63|1.63|2.46|1.27| |Warehouse|0.39|0.44|0.39|0.44|0.39|0.44|0.44|0.44|0.44|0.44|0.44|0.44|0.44|0.44|0.58|0.39| |Religious Worship|4.25|4.65|3.49|4.52|3.72|4.29|4.64|5.89|5.30|5.67|5.89|4.99|5.78|4.63|7.57|3.90| |Sports & Recreation|2.47|1.97|1.54|2.03|1.60|1.84|1.98|2.63|2.47|2.60|2.75|2.20|2.72|2.15|4.03|1.81| |Multifamily > 3 stories|1.82|2.21|1.82|2.21|1.82|2.21|2.21|2.21|2.21|2.21|2.21|2.21|2.21|2.21|2.77|1.82|
(h) Battery energy storage system (BESS) requirements—more than three habitable stories. All buildings that are required by Section 170.2(g) 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 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 )
268 2025 CALIFORNIA ENERGY CODE
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
MULTIFAMILY BUILDINGS—PERFORMANCE AND PRESCRIPTIVE COMPLIANCE APPROACHES
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.
§ 170.2 High relevance — show source text
All multifamily buildings up to three habitable stories shall have a newly installed photovoltaic (PV) system or newly installed PV modules meeting the minimum qualification requirements specified in Joint Appendix JA11. The annual electrical output of the PV system shall be no less than the smaller of a PV system size determined using Equation 170.2-C, or the total solar access roof area (SARA) multiplied by 18 for steep-sloped roofs or SARA multiplied by 14 for low-sloped roofs. A. SARA includes the area of the building’s roof space capable of structurally supporting a PV system, and the area of all roof space on covered parking areas, carports, and all other newly constructed structures on the site that are compatible with supporting a PV system per Title 24, Part 2, Section 1511.10.
B. SARA does NOT include:
i. Any roof area that has less than 70 percent annual solar access. Annual solar access is determined by dividing the total annual solar insolation, accounting for shading obstructions, by the total annual solar insolation if the same areas were unshaded by obstructions. For steep-sloped roofs, only shading from existing permanent natural or manmade obstructions that are external to the dwelling, including but not limited to trees, hills and adjacent structures, shall be considered for annual solar access calculations. For low slope roofs, all obstructions including those that are external to the dwelling unit, and obstructions that are part of the building design and elevation features, shall be considered for the annual solar access calculations.
ii. Occupied roof areas as specified by CBC Section 503.1.4. iii. Roof area that is otherwise not available due to compliance with: a. Other state building code requirements, or b. Local building code requirements if local building code requirements are confirmed by the Executive Director.
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.
§ 4.3.1 High relevance — show source text
Use Reference Joint Appendices JA4 Table 4.3.1, 4.3.1(a), or Table 4.3.4 to determine alternative insu-
lation products to be less than or equal to the required maximum U-factor.
4. Mass wall has a heat capacity greater than or equal to 7.0 Btu/h-ft2.
5. Product must be certified to meet the North American Fenestration Standard/Specification for an Architectural Window (AW).
6. Glazed doors must meet the fenestration requirements.
7. Requirements apply to doors included in the curtain wall/storefront construction assembly.
8. If using_F_-factor to comply, use Reference Joint Appendices JA4, Table 4.4.7 to determine alternate depth and R-value to be less than or equal to the required maximum_F_-
factor.
9. Option B meets §170.2(a)1Bii.
10. Option C meets §170.2(a)1BIiii.
11. Option D meets §170.2(a)1Biv.|1. Install the specified_R_-value with an airspace present between the roofing and the roof deck. Such as standard installation of concrete or clay tile.
2._ R_-values shown for below roof deck insulation are for wood-frame construction with insulation installed between the framing members. Alternatives including insulation
above rafters or above roof deck shall comply with the performance standards.
3. Assembly_U_-factors for exterior framed walls can be met with cavity insulation alone or with continuous insulation alone, or with both cavity and continuous insulation that
results in an assembly_U_-factor equal to or less than the_U_-factor shown. Use Reference Joint Appendices JA4 Table 4.3.1, 4.3.1(a), or Table 4.3.4 to determine alternative insu-
lation products to be less than or equal to the required maximum U-factor.
4. Mass wall has a heat capacity greater than or equal to 7.0 Btu/h-ft2.
5. Product must be certified to meet the North American Fenestration Standard/Specification for an Architectural Window (AW).
6. Glazed doors must meet the fenestration requirements.
7. Requirements apply to doors included in the curtain wall/storefront construction assembly.
8. If using_F_-factor to comply, use Reference Joint Appendices JA4, Table 4.4.7 to determine alternate depth and R-value to be less than or equal to the required maximum_F_-
factor.
9. Option B meets §170.2(a)1Bii.
10. Option C meets §170.2(a)1BIiii.
11. Option D meets §170.2(a)1Biv.|1. Install the specified_R_-value with an airspace present between the roofing and the roof deck. Such as standard installation of concrete or clay tile.
2._ R_-values shown for below roof deck insulation are for wood-frame construction with insulation installed between the framing members. Alternatives including insulation
above rafters or above roof deck shall comply with the performance standards.
3. Assembly_U_-factors for exterior framed walls can be met with cavity insulation alone or with continuous insulation alone, or with both cavity and continuous insulation that
results in an assembly_U_-factor equal to or less than the_U_-factor shown.§ 3.27 High relevance — show source text
05|3.27|3.45|3.83|3.65|3.81|4.09|3.64|3.99|3.71|4.60|3.21| |School|1.27|1.63|1.27|1.63|1.27|1.63|1.63|1.63|1.63|1.63|1.63|1.63|1.63|1.63|2.46|1.27| |Warehouse|0.39|0.44|0.39|0.44|0.39|0.44|0.44|0.44|0.44|0.44|0.44|0.44|0.44|0.44|0.58|0.39| |Religious Worship|4.25|4.65|3.49|4.52|3.72|4.29|4.64|5.89|5.30|5.67|5.89|4.99|5.78|4.63|7.57|3.90| |Sports & Recreation|2.47|1.97|1.54|2.03|1.60|1.84|1.98|2.63|2.47|2.60|2.75|2.20|2.72|2.15|4.03|1.81| |Multifamily > 3 stories|1.82|2.21|1.82|2.21|1.82|2.21|2.21|2.21|2.21|2.21|2.21|2.21|2.21|2.21|2.77|1.82|
TABLE 140.10-B—BESS CAPACITY FACTORS (Wh/ft2 of conditioned floor area) Col2 Col3 Col4 Col5 Col6 Col7 Col8 Col9 Col10 Col11 Col12 Col13 Col14 Col15 Col16 Col17 BUILDING TYPE CZ 1 CZ 2 CZ 3 CZ 4 CZ 5 CZ 6 CZ 7 CZ 8 CZ 9 CZ 10 CZ 11 CZ 12 CZ 13 CZ 14 CZ 15 CZ 16 Events & Exhibits 1.82 1.95 1.74 2.12 1.91 2.13 2.24 2.30 2.36 2.47 2.62 2.16 2.64 2.68 3.22 1.89 Library 0.37 7.17 5.97 6.75 5.64 6.08 6.19 7.13 7.18 7.56 7.17 6.93 6.88 6.81 7.93 6.40 Hotel/Motel 0.86 0.84 0.77 0.92 0.81 0.89 0.90 1.01 1.00 1. § 7.0 High relevance — show source text
Mass wall has a heat capacity greater than or equal to 7.0 Btu/h-ft2.
6. “Interior” denotes insulation installed on the inside surface of the wall. “Exterior” denotes insulation installed on the exterior surface of the wall.
7. Below grade “interior” denotes insulation installed on the inside surface of the wall, and below grade “exterior” denotes insulation installed on the outside surface of the wall.
8. HSPF2 means heating seasonal performance factor.
9. When whole-house fans are required (REQ), only those whole-house fans that are listed in the Home Ventilating Institute Certified Products Directory may be installed.
Compliance requires installation of one or more WHFs whose total airflow cfm is capable of meeting or exceeding a minimum 1.5 cfm/square foot of conditioned floor area as
specified by Section 150.1(c)12.
10. A supplemental heating unit may be installed in a space served directly or indirectly by a primary heating system, provided that the unit thermal capacity does not exceed 2
kilowatts or 7,000 Btu/h and is controlled by a time-limiting device not exceeding 30 minutes.
11. For duct and air handler location: REQ denotes location in conditioned space. When the table indicates ducts and air handlers are in conditioned space, a verification is
required as specified by Reference Residential Appendix RA3.1.4.3.8.
12. New dwelling units with a conditioned floor area of 500 square feet or less in Climate Zone 5 may comply with a maximum_U_-factor of 0.30.
13. Option B meets §150.1(c)9A.
14. Option C meets §150.1(c)9B.|1. Install the specified_R_-value with an air space present between the roofing and the roof deck, such as standard installation of concrete or clay tile.
2._ R_-values shown for below roof deck insulation are for wood-framed construction with insulation installed between the framing members. Alternatives including insulation
above rafters or above roof deck shall comply with the performance standards.
3. Assembly_U_-factors for exterior framed walls can be met with cavity insulation alone or with continuous insulation alone, or with both cavity and continuous insulation that
results in an assembly_U_-factor equal to or less than the_U_-factor shown. Use Reference Joint Appendices JA4 Table 4.3.1, 4.3.1(a), or Table 4.3.4 to determine alternative insu-
lation products to be less than or equal to the required maximum_U_-factor.
4. Assembly_U_-factors for roofs can be met with cavity insulation alone or with continuous insulation alone, or with both cavity and continuous insulation that results in an
assembly_U_-factor equal to or less than the_U_-factor shown. Use Reference Joint Appendices JA4 Table 4.2.2 to determine alternative insulation products to be less than or
equal to the required maximum_U_-factor.R-values shown represent the required insulation to meet the maximum_U_-factor with cavity insulation alone.
5. Mass wall has a heat capacity greater than or equal to 7.0 Btu/h-ft2.
6. “Interior” denotes insulation installed on the inside surface of the wall. “Exterior” denotes insulation installed on the exterior surface of the wall.
7.§ 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.
§ 170.1 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.
- 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.
- 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
2025 CALIFORNIA ENERGY CODE 237
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
MULTIFAMILY BUILDINGS—PERFORMANCE AND PRESCRIPTIVE COMPLIANCE APPROACHES
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.
Frequently asked questions
Do PV modules themselves need to be JA11‑listed, or only systems?
The code requires PV systems meeting the minimum qualification requirements in Reference Joint Appendix JA11 where § 140.10(a) applies. That means the components and system must comply with JA11’s requirements as applicable (see § 140.10(a)). Verify specific module vs system listing in JA11 itself.
Where do I find the numeric BESS “B” capacity factor to plug into Eq. 140.10‑B?
Use Table 140.10‑B in the Energy Code (BESS capacity factors by building type and climate zone); the equation in § 140.10(b) instructs you to use that table.
If my roof SARA is limited by shading, how does that affect sizing?
SARA excludes roof areas with less than 70% annual solar access and other specified exclusions in § 140.10(a). If SARA is used to set PV capacity (SARA × 18 or × 14), the BESS sizing equation 140.10‑C applies as the SARA‑adjusted multiplier.
Can installing a BESS reduce required PV size?
Some code sections allow a 25% reduction in required PV if installed with a qualifying JA12 BESS that meets a minimum cycling capacity (for example, 7.5 kWh in several residential/multifamily sections). See the specific section (e.g., § 150.1(c)14, § 170.2(f)) for the full rule and the JA12 requirement.
If the calculated BESS usable energy is less than 10 kWh, do I still need a BESS?
No — Exception 2 to § 140.10(b) states no BESS is required if the rated usable energy determined by the equations is less than 10 kWh.
More in California Energy Code
- Compliance paths, energy budgets, performance modeling and forms/software requirements
- Controls, commissioning, demand-response, sensors, and field verification/diagnostic testing
- Domestic hot water systems, efficiency, controls and installation requirements
- Electrical infrastructure, EV charging readiness, load management and demand controls
- Envelope construction, insulation, fenestration and thermal performance
- HVAC systems, ventilation rates, ducting, controls and testing
- Interior and exterior lighting power, controls and daylighting requirements
- Mandatory measures, appliance efficiency and certification requirements
- Photovoltaic requirements, BESS (battery energy storage) sizing and SARA procedures
- Reference appendices, test procedures, product certification and labeling requirements
- Scope, applicability, definitions and administrative requirements
Ask about the California Energy Code
Get cited, plain-English answers on the California Energy Code for your project — any code section, any scenario.
Start Free Trial