California Association of Building Energy Consultants

When is PV Solar Required under the 2022 Title 24 Part 6 Energy Code?

Section 150.1 excerpts below are from the 2022 Building Energy Efficiency Standards [PDF]

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

Section 150.1(c) 14

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 maximum PV system size that can be installed on the building's Solar Access Roof Area (SARA).

  1. 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 1511.2.
  2. SARA does NOT include:
    1. 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.
    2. Occupied roof areas as specified by CBC Section 503.1.4.
    3. Roof area that is otherwise not available due to compliance with other building code requirements if confirmed by the Executive Director.

Equation 150.1-C Annual Photovoltaic Electrical Output

WHERE:

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 kWdc.

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:

  1. Shading from roof designs and configurations for steep-sloped roofs, which are required by mandatory conditions for approval, shall be considered for the annual solar access calculations; and
  2. Roof areas that are not allowed by the mandatory conditions for approval to have PVs, shall not be considered in the 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 battery storage system. The battery storage system shall meet the qualification requirements specified in Joint Appendix JA12 and have a minimum usable capacity of 7.5 kWh.

Conclusions based upon the above Title 24 Part 6 Energy Code Sections

  1. An art studio, pool house, ADU and all other types of residential buildings that are NEWLY CONSTRUCTED will require PV Solar.

    Title 24 Part 6 Energy Code Definition: NEWLY CONSTRUCTED BUILDING is a building that has never been used or occupied for any purpose.

  2. An art studio, pool house, ADU and all other types of residential buildings that are attached to an existing, conditioned, low-rise residential building are ADDITIONS and are not required to have PV Solar. The attachment must be an attachment approved by the local building jurisdiction. Plans must indicate the attachment.
  3. ADDITIONALLY: If an art studio, pool house, or ADU is built over an existing garage, this is considered an addition to an existing structure. Not new construction. PV solar is not required. If an art studio, pool house, or ADU is built over a brand-new garage, (both being built as brand new), this is considered new construction and will require PV Solar.
  4. An unconditioned building converted to newly conditioned living space (such as a garage, shop, storage building) whether attached or detached to an existing conditioned low-rise residential building are ADDITIONS and are not required to have PV Solar (as it is not a newly constructed building).
  5. If a building department deems a "newly constructed" detached structure as an addition, the Title 24 Part 6 energy analysis can be calculated as an addition. Additions do not require PV solar under the 2019 Title 24 Part 6 Energy Code.

How to Prove the Exception for Shading

Contact a company that uses the CEC approved software to determine the building's SARA (Solar Access Roof Area). See list below of the CEC approved software providers. When that report is complete forward to CompuCalc or the CF-1R documentation author for review and possible recalculation of the CF-1R Energy Report.

Approved Solar Assessment Tools

The following solar assessment tools have been approved by CEC for use as specified in JA11.4(a):

CF2R Solar Access Verification

The CF2R-PVB-01-E, Certificate of Installation for Photovoltaic system requires a solar assessment report completed by an CEC approved solar assessment tool listed above. In addition, one of the following conditions must be met:

As always, I am available to discuss the process of meeting the California Energy Code for any building project. Contact me …