The 2022 Building Energy Efficiency Standards (Energy Code) has solar photovoltaic (solar PV) system requirements for all newly constructed single-family residential buildings. These are defined as:
- Townhouses
- Residential buildings of occupancy group R-3 with two or less dwelling units
- Buildings of occupancy groups:
- R-3, other than a multifamily or hotel/motel building
- R-3.1
- U, when located on a residential site
These requirements do not apply to additions or alterations to existing buildings, or unconditioned buildings.
The minimum required solar PV system is intended to offset the electrical consumption of the proposed building, as if it were a mixed fuel building (assumes a natural gas furnace, water heater, stove, and clothes dryer). This means electric heat pump space heating and water heating loads, and electric appliances will not affect the minimum solar PV system size requirement. The climate zone, conditioned floor area, and possible plug loads of a building will affect its cooling demand and therefore its required solar PV system size.
Prescriptive Compliance
Section 150.1(c)14 of the 2022 Energy Code has two methods to determine the minimum solar PV system size; the required size will be the smaller of the two methods.
- Maximum solar PV system size that can be installed on the building’s Solar Access Roof Area (SARA)
- A calculation (Equation 150.1-C), based on three factors:
- Climate zone of the building
- Conditioned floor area of the dwelling(s)
- Number of dwelling units
The Solar Access Roof Area (SARA) is the area of all roofs of a building, covered parking, carports, and newly constructed structures on the property capable of supporting a solar PV system per Title 24, Part 2, Section 1511.9. SARA excludes roof areas:
- With < 70 percent annual solar access, accounting for shading obstructions
- For steep sloped roofs, only existing permanent obstructions (e.g., trees, hills, nearby structures)
- For low sloped roofs, all obstructions including external obstructions and those that are part of the building design and elevation
- Occupied as specified by California Building Code Section 503.1.4
- Unavailable due to compliance with other code requirements, if confirmed by the California Energy Commission Executive Director
Performance Compliance
The minimum solar PV system size requirement will be based largely on the factors described above. Adding a battery storage system can reduce the required solar PV system size. Additionally, increasing the building’s energy efficiency (e.g., installing more efficient space cooling, increased insulation, etc.) will decrease its electrical consumption and decrease the required solar PV system size. However, installing a larger solar PV system in exchange for less energy efficiency is not allowed.
Yes. There are five exceptions that exclude single-family buildings from the solar PV requirement, or reduce the required size:
- SARA is < 80 contiguous square feet; for steep-sloped roofs, SARA excludes roof areas lying between 300 and 90 degrees of true north
- Minimum solar PV system size is < 1.8 kWdc
- The enforcement authority determines the solar PV system cannot meet the American Society of Civil Engineers Standard 7-16, Chapter 7, Snow Loads requirements
- Buildings approved by the local planning department prior to January 1, 2020, with mandatory conditions of approval
- If installed in conjunction with a battery storage system, the solar PV size per Equation 150.1-C may be reduced by 25 percent. The battery storage system must meet Reference Joint Appendix JA12 requirements, and have a minimum usable capacity of 7.5 kWh
No. Solar PV systems can be installed on the building’s SARA, ground-mounted on the property, or mounted atop a carport installed on the lot. Note: an alternative to installing solar PV on-site is to comply with community solar requirements when using the performance compliance approach if the CEC has approved a community solar program for the building type in the area where the building is located.
The solar-ready requirements under Section 110.10(b)-(e) are mandatory, but only apply to newly constructed single-family buildings that do not require a solar PV system located in subdivisions with 10 or more single-family residences, where the tentative subdivision map is deemed complete or approved by the enforcement agency. Note that solar-ready requirements do not apply to newly constructed accessory dwelling units built on an existing lot.
See the Blueprint for more information, including articles and frequently asked solar PV questions, about the 2022 Energy Code.