Title 24 · California Energy Code
What is SARA and which roof areas are included or excluded
SARA (Solar Access Roof Area) is the roof area the California Energy Code treats as available for photovoltaic systems — specifically roof area that can structurally support PV plus compatible covered parking/carports and new site structures, but excluding areas with less than **70% annual solar access**, occupied roofs, and areas barred by state/local code. The Code sizes PV by the smaller of a CFA‑based requirement or **SARA × 18 (steep)** / **SARA × 14 (low)**, with several small‑area and small‑system exceptions; see **§ 140.10(a)**, **§ 170.2(f)**, and **§ 150.1(c)14** for the exact rules and exceptions.
Last reviewed: July 6, 2026
What the code requires — 2–4 sentences
SARA (Solar Access Roof Area) is the portion of a site's roof area that is available and capable of structurally supporting photovoltaic (PV) equipment, plus compatible roof area on covered parking, carports, and newly constructed site structures. The Energy Code requires required PV capacity to be no greater than the smaller of a CFA‑based capacity or the total SARA multiplied by ×18 for steep‑sloped roofs or ×14 for low‑sloped roofs (see § 140.10(a), § 170.2(f), § 150.1(c)14).
The single most important rule: SARA = all roof area that is structurally capable of supporting PV and is not excluded by the code (notably areas with <70% annual solar access, occupied roof areas, or areas precluded by other state/local code requirements).
Requirements in detail
Core definition (what is included)
- Included: The area of the building’s roof space capable of structurally supporting a PV system, plus roof space on covered parking, carports, and other newly constructed site structures that are compatible with supporting PV per Title 24, Part 2, § 1511.10. This inclusion language appears in the nonresidential, multifamily, and single‑family sections of the Energy Code. (See § 140.10(a), § 170.2(f), § 150.1(c)14.)
Core exclusions (what is NOT SARA)
- Excluded: Areas that have less than 70 percent annual solar access (annual solar access is the ratio of actual annual insolation accounting for shading to the unshaded insolation for the same area). For steep slopes, shading from permanent external obstructions is handled differently than for low slopes—see the sections below. (See § 140.10(a), § 170.2(f), § 150.1(c)14.)
- Excluded: Occupied roofs as defined by the California Building Code (CBC § 503.1.4) are not part of SARA. (See § 140.10(a), § 170.2(f), § 150.1(c)14.)
- Excluded: Roof area that is otherwise not available due to other state building code requirements or local building code requirements (the latter only when confirmed by the Energy Commission Executive Director). (See § 140.10(a), § 170.2(f), § 150.1(c)14.)
Special shading rules by roof type
- For single‑family and multifamily steep‑slope roofs, the code provides different treatments of what shading counts when calculating annual solar access:
- Steep‑slope roofs (single‑family & multifamily): consider shading only from existing permanent natural or manmade obstructions that are external to the dwelling (trees, hills, adjacent structures). (See § 150.1(c)14 and § 170.2(f).)
- Low‑slope roofs: consider all obstructions, including those that are external to the building and those that are part of the building design/elevation features. (See § 150.1(c)14 and § 170.2(f).)
Azimuth (orientation) exclusion for steep slopes
- Steep‑slope roofs (single‑family & multifamily): roof areas with a northerly azimuth between 300° and 90° from true north are excluded from SARA for steep‑sloped roofs. (See Exception 1 to § 150.1(c)14 and Exception 1 to § 170.2(f).)
Numeric thresholds and decision points
Use the table below for quick, decision‑relevant thresholds and the code references.
| Decision item | Key value(s) | What that means in practice | Code Reference |
|---|---|---|---|
| Minimum annual solar access to be counted as SARA | 70% | Areas with <70% annual solar access are NOT SARA. | § 140.10(a) § 170.2(f) § 150.1(c)14 |
| Steep‑slope SARA multiplier | ×18 (W/ft²) | SARA × 18 = annual DC watts available (used to size PV). | § 140.10(a) § 170.2(f) § 150.1(c)14 |
| Low‑slope SARA multiplier | ×14 (W/ft²) | SARA × 14 = annual DC watts available for low slope. | § 140.10(a) § 170.2(f) § 150.1(c)14 |
| Small‑SARA exception (no PV required) | < 80 contiguous ft² | If SARA contains less than 80 contiguous ft², no PV system is required. | Exceptions to § 140.10(a) and § 170.2(f) and § 150.1(c)14 |
| Small output exception (nonresidential & multifamily) | PV required only if SARA-based capacity ≥ 4 kW dc (or CFA-based requirement larger) | If required PV size < 4 kW dc, no PV required (nonresidential/multifamily). | Exceptions to § 140.10(a) and § 170.2(f) |
| Small output exception (single‑family) | PV not required when minimum specified PV size < 1.8 kW dc | For single‑family only; threshold differs from multifamily/nonresidential. | Exception to § 150.1(c)14 |
| CFA‑relative exception (nonresidential & some multifamily) | < 3% of conditioned floor area (CFA) | If total available SARA < 3% of CFA, no PV required (nonresidential; similar exception appears for multifamily). | Exceptions to § 140.10(a) and § 170.2(g) |
| Occupied roofs (excluded) | per CBC § 503.1.4 | Rooftop areas intended for occupancy are not SARA. | Referenced in § 140.10(a), § 170.2(f), § 150.1(c)14 |
Where the SARA multiplier is used
- Each of the three sections requires sizing either by an equation based on conditioned floor area (CFA) or by the SARA × 18/14 method — whichever yields the smaller annual electrical output requirement to size the PV system. The SARA multiplier approach is explicitly in § 140.10(a), § 170.2(f), and § 150.1(c)14.
Exceptions & special cases
- Small SARA: if SARA < 80 contiguous ft², no PV required (applies across the sections' exceptions).
- Small required system: nonresidential & multifamily — if minimum PV requirement < 4 kW dc, PV may be not required; single‑family uses 1.8 kW dc as the small‑system exemption. (See exceptions in each section.)
- Snow‑load structural infeasibility: enforcement authorities may approve an exception when the roof cannot safely support PV to meet ASCE 7‑16 Chapter 7 (Snow Loads); this is an explicit exception in each PV section. (See § 140.10(a) exceptions; § 170.2(f) exceptions; § 150.1(c)14 exceptions.)
- Multifamily special planning approvals: projects with mandatory planning conditions prior to Jan 1, 2020 may treat shading/areas differently per exceptions to § 170.2(f) and § 150.1(c)14.
- BESS interactions: installing a qualifying battery energy storage system (BESS) may reduce required PV sizes in some cases (see exceptions that allow percent reductions when BESS is installed). These are referenced as exceptions in the multifamily and single‑family provisions.
Common mistakes
- Assuming every square foot of roof is SARA: the code excludes areas with <70% annual solar access, occupied roofs, and areas blocked by other code requirements — you must run the insolation/shading test and check occupancy/codes before counting area. (See § 140.10(a), § 170.2(f), § 150.1(c)14.)
- Using the wrong shading rules for steep vs low slopes: for steep slopes you may not count some internal building elevation obstructions the same way you do for low slopes. Confirm whether the roof is treated as steep or low per the section language. (See § 150.1(c)14 and § 170.2(f).)
- Forgetting the azimuth exclusion on steep slopes: areas with northerly azimuth 300°–90° are excluded for steep‑slope SARA in the single‑family and multifamily provisions — don’t count those panel‑unfriendly roof faces. (See Exception 1 to § 150.1(c)14 and Exception 1 to § 170.2(f).)
- Overlooking contiguous area requirement: SARA exceptions refer to contiguous area. Scattered small patches totaling >80 ft² but not contiguous may not qualify to avoid the small‑area exception. (See exceptions to § 140.10(a), § 170.2(f), §150.1(c)14.)
Worked example — single, concrete scenario
Scenario: A new single‑family home has:
- Conditioned floor area (CFA): 2,400 ft² (used to compute CFA‑based PV size by Equation 150.1‑C, not calculated here).
- A single continuous south‑facing steep‑slope roof area that the structural engineer confirms can carry PV: SARA = 400 ft² contiguous and meets annual solar access >70%.
Step 1 — compute SARA‑based PV capacity:
- For steep‑sloped roofs, the Energy Code uses SARA × 18 (W/ft²). So 400 ft² × 18 = 7,200 W dc = 7.2 kW dc available by SARA method. (See § 150.1(c)14.)
Step 2 — check small‑system exceptions:
- Single‑family small PV exemption applies only if the minimum specified PV size (from CFA equation or SARA method) is < 1.8 kW dc. Here, 7.2 kW >> 1.8 kW, so the exemption does NOT apply. (See Exception 2 to § 150.1(c)14.)
Step 3 — check contiguous minimum:
- SARA = 400 contiguous ft² (>> 80 ft²), so the contiguous‑area exception does not block PV. (See exceptions to § 150.1(c)14.)
Result: The builder must provide a PV system sized according to the smaller of the CFA‑based requirement (Equation 150.1‑C) or the SARA‑based capacity (7.2 kW dc). If the CFA equation produces a smaller annual output requirement than 7.2 kW, the CFA result governs; otherwise the SARA result (7.2 kW) governs. (See § 150.1(c)14.)
If instead this were a large nonresidential building with CFA = 50,000 ft² and total available SARA = 1,000 ft²: the 3% CFA test (3% of 50,000 = 1,500 ft²) shows SARA < 3% of CFA, so no PV system would be required under the nonresidential exception. (See Exception 1 to § 140.10(a).)
Related provisions
- § 1511.10 (Title 24, Part 2) — referenced rule on structures compatible with supporting PV (SARA includes structures compatible per § 1511.10).
- CBC § 503.1.4 — defines occupied roofs, which the Energy Code excludes from SARA (referenced in the SARA language).
- ASCE 7‑16, Chapter 7 (Snow Loads) — cited in the Energy Code exceptions where enforcement authorities may exempt roofs unable to meet snow‑load requirements for PV attachments.
- For multifamily and nonresidential battery interactions and sizing reductions, see the BESS sections and exceptions in § 140.10(b) and § 170.2(h).
Code references
Grounded in the retrieved California Energy Code — click a citation to read the verbatim passage:
§ 1511.10. High relevance — show source text
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.
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EQUATION 140.10-A—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 140.10-A for the building type.
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.
§ 1511.10. High relevance — show source text
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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 slope 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 150.1-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.
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.
§ 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.
§ 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.
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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.
§ 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.
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EQUATION 140.10-A—PHOTOVOLTAIC DIRECT CURRENT CAPACITY
kW PVdc = (CFA × A)/1000
where:
kW PVdc = Minimum rated PV system capacity in kW.
§ 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.
§ 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.
§ 150.1 High relevance — show source text
Exception 1 to Section 150.1(c)11: Building integrated photovoltaic panels and building integrated solar thermal panels are not required to comply with the minimum requirements for aged solar reflectance and thermal emittance or SRI. Exception 2 to Section 150.1(c)11: Roof constructions with a weight of at least 25 lb/ft [2] are not required to comply with the minimum requirements for aged solar reflectance and thermal emittance or SRI. 12. Ventilation cooling. Single-family homes shall comply with the whole-house fan (WHF) requirements shown in Table 150.1A. When a WHF is required, comply with Subsections A, B and C below. A. Have installed one or more WHFs whose total airflow cfm is equal to or greater than 1.5 cfm/ft [2] of conditioned floor area. Airflow cfm for WHFs shall be determined based on the airflow listed in the Home Ventilating Institute Certified Products Directory. B. Have at least 1 square foot of attic vent free area for each 750 cfm of rated whole-house fan airflow cfm, or if the manufacturer has specified a greater free vent area, the manufacturer’s free vent area specifications. Exception to Section 150.1(c)12B: WHFs that are directly vented to the outside. C. Provide homeowners who have WHFs with a one page “How to operate your whole-house fan” informational sheet. Exception to Section 150.1(c)12: New dwelling units with a conditioned floor area of 500 square feet or less shall not be required to comply with the WHF requirements. 13. HVAC system bypass ducts. Bypass ducts that deliver conditioned supply air directly to the space-conditioning system return duct airflow shall not be used.
- Photovoltaic requirements. All single-family residential buildings 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 150.1-C, or the total solar access roof area (SARA) multiplied by 18 for steep-sloped roofs or multiplied by 14 for low-sloped roofs.
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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 slope 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.
§ 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.
§ 150.1 Medium 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 Medium 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.
Frequently asked questions
What counts as "structurally capable" for SARA?
A structural determination must show the roof can support the PV system (modules, racks, attachments) including applicable loads (dead, live, snow, seismic) per design standards; the Energy Code’s SARA definition assumes that only roof areas confirmed structurally capable are included. See § 140.10(a), § 170.2(f), § 150.1(c)14.
How do I test the 70% annual solar access threshold?
Annual solar access is the ratio of total annual solar insolation (accounting for shading) to the total annual insolation if unshaded. If that ratio is below 70%, the area is excluded from SARA. Different shading inputs apply for steep vs low slopes per the sections. (See § 140.10(a), § 170.2(f), § 150.1(c)14.)
Do rooftop decks count as SARA?
No. Occupied roofs (as identified by CBC § 503.1.4) are excluded from SARA; the Energy Code explicitly excludes occupied roof areas. (See § 140.10(a), § 170.2(f), § 150.1(c)14.)
When can local rules remove roof area from SARA?
If a local building code prohibits PV on certain roof areas, those areas are not counted as SARA—but the Energy Commission’s Executive Director must confirm local code requirements for exclusion. (See § 140.10(a), § 170.2(f), § 150.1(c)14.)
If my SARA is small, is PV still required?
There are specific small‑SARA and small‑system exceptions: e.g., SARA < 80 contiguous ft² typically removes the PV requirement; also system‑size minimums (4 kW for nonresidential/multifamily; 1.8 kW for single‑family) can eliminate the requirement when the required PV would be below those thresholds. Check the applicable section for your building type.
More in California Energy Code
- Compliance paths, energy budgets, performance modeling and forms/software requirements
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- 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
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