How to Meet COOL Roof Code Requirements in California

The California Energy Commission updates Part 6 of Title 24 every three years, with the next round of updates scheduled for 2025.

Cool roof requirements in California vary by region. You should always check with your local jurisdiction to see which requirements apply to your building, as codes are constantly evolving and limits for individual locales may be stricter than those discussed here.

Understanding Solar Reflectance Index (SRI)

Cool roof codes in California require roofs meet the minimum aged Solar Reflectance (SR) and Thermal Emmitance (TE) efficiencies or the meet minimum Solar Reflectance Index (SRI).

For roofing materials, SRI is a calculation using the solar reflectance and thermal emittance measurements of the asphalt shingles materials. It ranges from 0 to 100. This measurement can be used as an indicator of how hot shingles are likely to become when they’re exposed to the sun.

• The lower the SRI value, the hotter the material is likely to become in sunlight.
• Material with a higher SRI value will stay cooler in sunlight. Roofing shingles with a higher SRI may help lower household energy consumption by keeping the roof cooler and may also help decrease CO₂ emissions

California COOL Roof Code Requirements: Know Your Zone

The state of California is broken down into 16 climate zones as defined in California’s Building Energy Efficiency Standards Title 24, Part 6. Know your zone and get familiar with the specific roofing requirements you must meet before starting any roofing project.

As of today, the following table and map shows how the cool roof code requirements vary by region, barring local code adoption/ enforcement from individual jurisdictions. 

The City of Los Angeles Cool Roof Code Requirements

First, for the City of Los Angeles, asphalt shingles must either meet or exceed an SRI value of 20 for all new construction and reroof applications in residential and commercial buildings. This is a mandatory requirement per the City of Los Angeles Cool Roof requirements.

Los Angeles County Cool Roof Code Requirements

Second, for the unincorporated areas of Los Angeles County, asphalt shingles must meet or exceed a 3-year aged SR value of 0.25 and an initial thermal emittance value of 0.85. As an alternative, an SRI value of 20 for all new construction and reroof applications in residential and commercial buildings is required. This is a mandatory requirement per the Green Building Standards Code of Los Angeles County.

State of California COOL Roof Code Requirements

Barring overriding local requirements, the rest of California falls under the requirements contained in California’s Building Energy Efficiency Standards Title 24, Part 6. Whether any requirements may apply is based on the building’s location relative to the 16 California climate zones established in the Standards.

For zones 1-9 and 16, there are no cool roof requirements. In climate zones 10-15, there are several options for compliance with the energy efficiency requirements. Additional attic/roof insulation, installation of a radiant barrier, or “cool” roofing are the three options. With respect to asphalt shingles, they must meet or exceed an SRI of 16 for all new construction applications and reroof applications when greater than 50% of the roof is removed.

These criteria apply to all residential and commercial buildings. In zones 10-15, installing a cool roof with an SRI that meets or exceeds 16 is one of three options to demonstrate code compliance. Therefore, a cool roof is considered a ‘tradeoff’ option.

Asphalt shingles with an SRI value under 16 can be used in these areas if they are installed in conjunction with a radiant barrier and an air space, or if additional attic insulation accompanies the shingle installation.

You can refer to the Building Energy Efficiency Standards Title 24, Part 6 for the details on these alternative compliance paths. In most cases, contractors are complying with the code by installing a cool asphalt shingle roof that meets or exceeds 16 SRI.

Roofing Shingles That Meet California Cool Roof Codes

Owens Corning^® COOL Roof Collection asphalt shingles use the minimum SRI compliance path to meet the various cool roof codes in California. Owens Corning uses a shingles third-party certified aged SRI value to demonstrate compliance with cool roof energy codes in California.

Owens Corning has designed its COOL Roof Collection to help homeowners and contractors meet the state’s building codes.

The complete COOL Roof Collection is only available in California. This selection of asphalt roofing shingles includes:

• 34 products that meet or exceed 16 SRI
• 16 products that meet or exceed 20 SRI

Because so many shingles from the COOL Roof Collection align with state requirements, contractors, builders, and homeowners in California can choose from a wide range of colors to meet the energy standards.

Details on all shingle products and colors available for the California market can be found on our COOL Roof Collection page.

Start Your California Cool Roofing Project Today

Ready to take the next step towards building an energy-efficient home? Whether you’re embarking on a reroofing project or adding the finishing touches on your newly constructed house, Owens Corning Roofing can help.

Owens Corning COOL Roof Collection asphalt roofing shingles meet various levels of California Cool roofing requirements in a great selection of colors that complement many home exteriors.

Be sure to take advantage of California’s incentive programs for home and business owners who use cool roofing materials.

Find Owens Corning COOL roofing shingles available in your area along with a trusted independent contractor in the Owens Corning Contractor Network.