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What is a cool roof, and is one required for a reroof in San Francisco?

Short answerUsually not in San Francisco. A cool roof is a product rated to reflect sunlight and shed heat, and California requires one on qualifying reroofs only in certain climate zones. Most homes here sit outside them. You can still choose a reflective product. Find your city below and get a free written estimate.

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Updated · Sources reviewed November 12, 2026 · By SF Roof Replacement

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What is a cool roof?

Cool roofs are products with tested, rated solar reflectance and thermal emittance. California's Energy Code relies on Cool Roof Rating Council listings and on aged (weathered) values, not new ones.

What does the Energy Code require?

Here's the rule, from the Energy Commission (CEC): when a reroof replaces more than half of the roof, a steep-slope roof in zones 4 or 8 to 15 needs an aged reflectance of at least 0.20 with emittance of 0.75 (or SRI 16), and a low-slope roof in zones 4 or 6 to 15 needs 0.63 and 0.75 (or SRI 75). Some exceptions apply.

Which San Francisco cities need a cool roof?

City CEC climate zone Steep-slope reroof: cool roof required? Low-slope reroof: cool roof required?
San Francisco 3 No No

Climate zones are from the Energy Commission's ZIP code list (CEC climate zones); a few ZIPs straddle zones, so confirm yours with the city.

What's different about San Francisco?

All of San Francisco is in climate zone 3. Because the prescriptive cool-roof rules apply only in zones 4 and 6 to 15 (low-slope) and 4 and 8 to 15 (steep-slope), San Francisco's many flat roofs behind parapets don't need a rated cool-roof product on a reroof. Light-colored membranes and coatings are still common on flat roofs because they're often standard products, not because the city requires them. DBI's reroofing permit is the main paperwork (SF.gov).

What should I ask my roofer?

Ask the roofer to name the product and its CRRC listing on the estimate, and keep the label for your permit final. For your actual price, request a free written estimate: a licensed roofer measures the roof and prices your exact scope. See also metal vs. shingles, what drives cost and permits.

Every roofer we work with is licensed, insured and highly reviewed by Bay Area homeowners.

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Frequently asked questions

Where do I find a product's cool-roof rating?

The Cool Roof Rating Council's product directory lists rated products.

Does a partial reroof need a cool roof?

The rule applies when more than half of the roof is replaced.

Related questions

Sources

Sources reviewed November 12, 2026. Figures are published estimates and official fees, not quotes. Confirm prices, permits and requirements with your contractor and building department. This page is general information, not legal or insurance advice.