Title 24 · California Energy Code
When PV size may be reduced (BESS credit) and contiguous SARA area requirements
Plain English: If you add a JA12‑qualified battery of at least 7.5 kWh with your required PV, California’s energy code lets you size the PV 25% smaller (Exception 5 to § 170.2(f)). Separately, if your usable roof area for solar (SARA) is less than 80 square feet in one contiguous patch, you generally don’t have to install PV (Exception 3 to § 140.10(a)).
Last reviewed: July 6, 2026
What the code requires — plain English (controlling §)
- A building’s mandatory PV requirement calculated under § 170.2(f) may be reduced by 25% where the PV is installed together with a qualifying battery energy storage system (BESS) that meets the Joint Appendix JA12 qualifications and a minimum cycling capacity of 7.5 kWh; this is Exception 5 to § 170.2(f).
- Separately, no PV is required when the building’s solar access roof area (SARA) contains less than 80 contiguous square feet; this is Exception 3 to § 140.10(a).
The single most important practical rule: if you plan to take the 25% PV reduction, you must pair the PV with a JA12‑qualified BESS that meets the specified minimum capacity; if your contiguous SARA is under 80 ft² there may be no PV obligation at all.
Requirements in detail
BESS credit — 25% PV size reduction (Exception 5 to § 170.2(f))
- What the code allows: PV capacity determined by the applicable equation (for example Equation 170.2‑C or 170.2‑D where used) may be reduced by 25% when a qualifying BESS is installed with the PV. Exception 5 to § 170.2(f) is the controlling provision.
- BESS qualification: the BESS must meet the qualification requirements in Joint Appendix JA12 and have a minimum cycling capacity of 7.5 kWh as defined in JA12. The code text ties the reduction explicitly to these qualification requirements.
- How it is applied: compute the required PV size from the applicable equation (e.g., Equation 170.2‑C or 170.2‑D for multifamily), then reduce that required capacity by 25% when the qualifying BESS is provided. Equation references and PV sizing equations are shown in the code text.
Decision‑relevant values (quick reference):
| Decision dimension | Value / threshold | Code Reference |
|---|---|---|
| PV size reduction allowed | 25% reduction of required PV when paired with BESS | Exception 5 to § 170.2(f) |
| BESS minimum cycling capacity to qualify | 7.5 kWh (minimum cycling capacity as defined in JA12) | Exception 5 to § 170.2(f) / JA12 |
| Governing PV sizing equation (example) | Equation 170.2‑C (annual PV electrical output formula) | § 170.2(f) discussion / Equation 170.2‑C |
Contiguous SARA exclusion (Exception 3 to § 140.10(a))
- What the code allows: when the calculated SARA contains less than 80 contiguous square feet, no PV system is required under § 140.10(a) (this is Exception 3). The same 80 ft² contiguous rule appears in other PV sections (see related provisions).
- What “contiguous” means here in practice: the code compares continuous roof area that is structurally available and meets the SARA rules; discontiguous patches separated by obstructions do not count as a single contiguous area. The SARA definition and the exclusions (for example exclusions of roof areas with <70% annual solar access, occupied roofs, or areas disallowed by other code/local requirements) inform the measurement.
Decision‑relevant values (quick reference):
| Decision dimension | Value / threshold | Code Reference |
|---|---|---|
| Contiguous SARA threshold to exempt PV | < 80 ft² contiguous → no PV required | Exception 3 to § 140.10(a) |
| SARA annual solar access cutoff (excludes from SARA) | < 70% annual solar access → area not included in SARA | § 140.10 / SARA definition |
| Alternate SARA rule (multifamily sections) | If SARA < 3% of CFA → may be no PV required (alternate exception in § 170.2(g)) | § 170.2(g) Exception 1 |
Exceptions & special cases
- The BESS credit applies only when the BESS actually meets JA12 requirements and the 7.5 kWh cycling capacity minimum — an arbitrary battery will not qualify. Exception 5 to § 170.2(f) ties the credit to JA12 qualification.
- Other PV exceptions may remove the PV requirement entirely even if you don’t claim the BESS credit: for example, some sections say no PV is required when the required PV is below a numeric floor (e.g., less than 4 kW dc in some multifamily provisions). Check the specific section that applies to your building type before applying the BESS reduction.
- The 80 ft² contiguous rule is specific to the SARA measurement used in § 140.10(a) (nonresidential/hotel/motel) — other parts of the code (e.g., multifamily §§ 170.2(f)/(g)) repeat the contiguous‑80‑ft² exception or use related SARA‑based exceptions (see related provisions). Always verify which PV section applies to your project.
Common mistakes
- Assuming any battery qualifies: the BESS must be JA12‑qualified and meet the 7.5 kWh cycling criterion — failing to document JA12 conformance voids the credit.
- Counting non‑contiguous roof patches as one contiguous SARA area; the code requires contiguous area for the 80 ft² exclusion.
- Applying the 25% reduction before confirming which PV sizing method/Equation governs the project (i.e., compute the code‑required PV first, then reduce). The reduction is applied to the PV size determined by the governing equation.
- Overlooking other exceptions (e.g., required PV < 4 kW dc may already trigger a no‑PV exception) and stacking inappropriate credits. Verify all applicable exceptions in the section that controls the project type.
Worked example — apply the BESS credit
Assumptions (illustrative):
- Project subject to § 170.2(f) PV sizing using an equation that yields a required PV capacity of 20.0 kW dc before credits. (Compute this using the applicable equation such as Equation 170.2‑C or 170.2‑D as appropriate.)
- The owner installs a JA12‑qualified BESS meeting the 7.5 kWh minimum cycling capacity.
Steps and result:
- Determine the required PV capacity per the applicable code equation: 20.0 kW dc (example).
- Apply the 25% reduction allowed by Exception 5 to § 170.2(f) because a qualifying BESS is installed: 20.0 kW × (1 − 0.25) = 15.0 kW dc. The PV system may be sized at 15.0 kW dc for compliance purposes.
Notes:
- If other exceptions apply (for example, if the initial required PV had been below a separate numeric floor that triggers no PV required), those exceptions take effect per their own text and could supersede the need to apply the BESS credit. Always check the full set of exceptions in the controlling PV section.
Related provisions
- § 170.2(f) — Photovoltaic requirements (multifamily, three habitable stories or fewer) and the list of exceptions (including Exception 5).
- § 170.2(g) — Photovoltaic requirements (more than three habitable stories), SARA rules and related exceptions (e.g., SARA < 80 contiguous ft² / SARA < 3% CFA).
- § 140.10(a) — Photovoltaic direct current capacity for nonresidential/hotel/motel occupancies and Exception 3 (SARA < 80 contiguous ft²).
- Equation 170.2‑C / 170.2‑D — PV sizing equations referenced in the PV sections (use these to compute the baseline PV before any BESS credit).
- Joint Appendix JA12 — BESS qualification requirements referenced by the Exception that allows the 25% reduction (see Exception 5 to § 170.2(f)).
If you want, I can:
- run the exact PV sizing calculation for your project (need CFA, number of dwelling units or building type and climate zone), and then show the numeric BESS‑credited PV size; or
- draft the BESS/JA12 documentation checklist an enforcement authority will expect to see when you claim the 25% reduction.
Code references
Grounded in the retrieved California Energy Code — click a citation to read the verbatim passage:
§ 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,
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and obstructions that are part of the building design and elevation features, may be considered for the annual solar access calculations.
§ 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.
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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.
§ 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.
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|TABLE 150.
§ 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 )
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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.
§ 170.2 High relevance — show source text
ii. Reserved.
iii. Neon or cold cathode lamps with transformer or power supply efficiency greater than or equal to the following: a. A minimum efficiency of 75 percent when the transformer or power supply rated output current is less than 50 mA; or
b. A minimum efficiency of 68 percent when the transformer or power supply rated output current is 50 mA or greater. The ratio of the output wattage to the input wattage is at 100 percent tubing load.
iv. Reserved.
v. Light emitting diodes (LEDs) with a power supply having an efficiency of 80 percent or greater; or Exception to Section 170.2(e)7Bv: Single voltage external power supplies that are designed to convert 120 volt AC input into lower voltage DC or AC output, and have a nameplate output power less than or equal to 250 watts, shall comply with the applicable requirements of the Appliance Efficiency Regulations (Title 20). Exception 1 to Section 170.2(e)7: Unfiltered incandescent lamps that are not part of an electronic message center (EMC), an internally illuminated sign or an externally illuminated sign. Exception 2 to Section 170.2(e)7: Exit signs. Exit signs shall meet the requirements of the Appliance Efficiency Regulations. Exception 3 to Section 170.2(e)7: Traffic signs that meet the requirements of the Appliance Efficiency Regulations, Sections 1601(m), 1602, 1602.1, 1603, 1604(m), 1605, 1605.1(m), 1605.2(m), 1605.3(m), 1606, 1607, 1608, and 1609.
(f) Photovoltaic requirements—three habitable stories or fewer . 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.
§ 150.1 High relevance — show source text
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.
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TABLE 150.1-A COMPONENT PACKAGE—SINGLE-FAMILY STANDARD BUILDING DESIGN Col2 Col3 Col4 Col5 Col6 Col7 Col8 Col9 Col10 Col11 Col12 Col13 Col14 Col15 Col16 Col17 BUILDING COMPONENT
ROOFS AND CEILINGSCZ 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 Option B13
Below Roof Deck
Insulation**1,§ 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.
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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. § 170.2 High relevance — show source text
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,
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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.
EQUATION 170.2-D—PHOTOVOLTAIC DIRECT CURRENT CAPACITY
kW PVdc = (CFA × A)/1000
where:
kW PVdc = Minimum rated PV system capacity in kW.
CFA = Conditioned floor area in square feet.
A = PV capacity factor in W/square foot as specified in Table 170.2-U for the building type.
Exception 1 to Section 170.2(g): 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 170.2(g): No PV system is required where the required PV system capacity is less than 4 kW dc .
Exception 3 to Section 170.2(g): No PV system is required if the SARA contains less than 80 contiguous square feet.
Exception 4 to Section 170.2(g): 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.
California Energy Code High relevance — show source text
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| |2000|38|79|148|304|455|877|1400|2470|5040|§ 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.
§ 4.44 High relevance — show source text
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/Clinic|2.59|3.13|2.59|3.13|2.59|3.13|3.13|3.13|3.13|3.13|3.13|3.13|3.13|3.13|3.80|2.59| |Restaurant|8.55|9.32|8.16|9.65|8.21|8.73|9.11|10.18|9.75|10.28|10.85|9.73|10.69|9.73|12.25|8.47| |Retail, Grocery|3.14|3.49|3.01|3.61|3.05|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|(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.
§ 304A.3.5.13 High relevance — show source text
304A.3.5.13 ASCE 41-13 Section 10.7.1.1. Modify ASCE 41-13 Section 10.7.1.1 with the following:
Monolithic Reinforced Concrete Shear Walls and Wall Segments. For nonlinear procedures, shear walls or wall segments with axial loads greater than 0.35 Po shall be included in the model as primary elements with appropriate strength and stiffness degrading properties assigned to those components subject to the approval of the enforcement agent. For linear procedures, the effects of deformation compatibility shall be investigated using moment-curvature section analyses and cyclic testing results of similar components to determine whether strengthening is necessary to maintain the gravity load-carrying capacity of that component.
Horizontal wall segments or spandrels reinforced similar to vertical wall segments or piers shall be classified as wall segments, not shear wall coupling beams, in Tables 10-19 through 10-22.
304A.3.5.14 ASCE 41-13 Section 10.12.3 Modify ASCE 41-13 Section 10.12.3 as follows:
Exception: Component actions that are deformation controlled are permitted to use their expected strengths for the accep- tance criteria.
304A.3.5.15 ASCE 41-13 Section 11.1. Modify ASCE 41-13 Section 11.1 by the following:
Scope: Unreinforced masonry walls (including unreinforced infill walls) and partitions are not permitted for General Acute Care (GAC) hospital buildings.
304A.3.5.16 ASCE 41-13 Section 14.1. Modify ASCE 41-13 Section 14.1 by the following:
Scope: For buildings located in Seismic Design Category F, verification of the interstory lateral displacements, the strength adequacy of the seismic force-resisting system and anchorage to the foundation shall be accomplished using the Nonlinear Dynamic Procedure.
304A.3.5.17 ASCE 41-13 Chapter 15 and 16. Not permitted by OSHPD.
304A.3.6 Modifications to ASCE 41-23. The text of ASCE 41-23 shall be modified as indicated in Sections 304A.3.6.1 through 304A.3.6.9.
304A.3.6.1 ASCE 41-23 Section 2.1. Modify ASCE 41-23 Section 2.1 with the following:
Seismic evaluations shall be performed for performance objective specified in Section 304A.3.4 of this code (CEBC) using proce- dure of this standard (ASCE 41-23) as follows:
1. Structural components shall be evaluated in accordance with Tier 3 systematic evaluations procedure in Chapter 6.
2. Nonstructural components shall be evaluated in accordance with Chapter 13.
Exception: For general acute care hospitals, seismic evaluation shall be permitted to be in accordance with Chapter 6 of the California Administrative Code (CAC) when required by provisions of that chapter.
304A.3.6.2 ASCE 41-23 Section 6.2. Modify ASCE 41-23 Section 6.2 with the following:
Frequently asked questions
What exactly must the battery meet to get the 25% reduction?
The BESS must be JA12‑qualified and have at least 7.5 kWh minimum cycling capacity as defined in Joint Appendix JA12. This is required by Exception 5 to § 170.2(f).
Do I reduce the PV required by 25% before or after other exceptions?
Compute the baseline PV required by the governing equation (e.g., Equation 170.2‑C/D or 140.10‑A). If you are eligible for the BESS credit, apply the 25% reduction to that baseline. Other exceptions (like “no PV if required PV < 4 kW” or SARA‑based exceptions) can eliminate the obligation entirely and must be checked first.
How do I measure the 80 ft² contiguous SARA?
Measure continuous roof area that meets the SARA rules (structurally capable of supporting PV and not excluded by SARA exclusions such as <70% annual solar access or occupied roof areas). Separate patches divided by obstructions are not combined to make a contiguous 80 ft². Exception 3 to § 140.10(a) is the controlling text.
If my SARA is just under 80 ft², is there any alternative?
If SARA is under 80 contiguous ft² the code says no PV is required under that exception; however, check other related exceptions (for example percent‑of‑CFA rules) and local enforcement practice. Confirm measurements and calculations with the enforcement authority.
Can I combine the BESS credit with other credits or programs?
The code text grants the 25% BESS credit when the qualifying BESS is installed; other program credits or local incentives may exist, but confirm that they are compatible with code compliance and whether the enforcement authority or the compliance software requires separate documentation of JA12 conformance.
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