What is a cool roof?
"Cool roof" is a rating, not a color: the product's aged solar reflectance and thermal emittance are tested and listed by the Cool Roof Rating Council. Many darker-looking shingles and tiles now carry cool ratings.
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 the Peninsula cities need a cool roof?
| City | CEC climate zone | Steep-slope reroof: cool roof required? | Low-slope reroof: cool roof required? |
|---|---|---|---|
| Daly City | 3 | No | No |
| South San Francisco | 3 | No | No |
| San Bruno | 3 | No | No |
| Pacifica | 3 | No | No |
| Millbrae | 3 | No | No |
| Burlingame | 3 | No | No |
| Hillsborough | 3 | No | No |
| San Mateo | 3 | No | No |
| Foster City | 3 | No | No |
| Belmont | 3 | No | No |
| San Carlos | 3 | No | No |
| Redwood City | 3 | No | No |
| Atherton | 3 | No | No |
| Menlo Park | 3 | No | No |
| Woodside | 3 | No | No |
| Half Moon Bay | 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 the Peninsula?
Every Peninsula city in our table, from Daly City to Menlo Park and Half Moon Bay, is in climate zone 3, so a home reroof here doesn't trigger the prescriptive cool-roof rule, steep or low slope. If a contractor tells you a cool roof is mandatory on a San Mateo County home, ask them to point to the specific rule.
What should I ask my roofer?
Make sure the bid names a CRRC-listed product, and keep the documentation; inspectors may ask for it. 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.
Get a free replacement quoteFrequently asked questions
Is a cool roof required in all of California?
No. It depends on the climate zone and whether more than half the roof is replaced.
Does a partial reroof need a cool roof?
The rule applies when more than half of the roof is replaced.
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.