What is a cool roof?
A cool roof is a roofing product tested and rated for solar reflectance (how much sunlight it bounces back) and thermal emittance (how well it releases heat). Ratings come from the Cool Roof Rating Council, and the Energy Code uses the aged values after weathering.
What does the Energy Code require?
The Energy Commission's minimums (CEC guide): steep slope, zones 4 and 8 to 15, aged solar reflectance 0.20 and emittance 0.75 or SRI 16; low slope, zones 4 and 6 to 15, aged reflectance 0.63 and emittance 0.75 or SRI 75. They apply when more than half the roof is replaced, with exceptions.
Which South Bay cities need a cool roof?
| City | CEC climate zone | Steep-slope reroof: cool roof required? | Low-slope reroof: cool roof required? |
|---|---|---|---|
| San Jose | 4 | Yes, unless an exception applies | Yes, unless an exception applies |
| Santa Clara | 4 | Yes, unless an exception applies | Yes, unless an exception applies |
| Sunnyvale | 4 | Yes, unless an exception applies | Yes, unless an exception applies |
| Mountain View | 4 | Yes, unless an exception applies | Yes, unless an exception applies |
| Palo Alto | 4 | Yes, unless an exception applies | Yes, unless an exception applies |
| Los Altos | 4 | Yes, unless an exception applies | Yes, unless an exception applies |
| Cupertino | 4 | Yes, unless an exception applies | Yes, unless an exception applies |
| Campbell | 4 | Yes, unless an exception applies | Yes, unless an exception applies |
| Saratoga | 4 | Yes, unless an exception applies | Yes, unless an exception applies |
| Los Gatos | 4 | Yes, unless an exception applies | Yes, unless an exception applies |
| Milpitas | 4 | Yes, unless an exception applies | Yes, unless an exception applies |
| Morgan Hill | 4 | Yes, unless an exception applies | Yes, unless an exception applies |
| Gilroy | 4 | Yes, unless an exception applies | Yes, unless an exception applies |
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 South Bay?
Every Santa Clara County city in our table is in climate zone 4, so cool-roof rules apply to qualifying reroofs on both steep-slope and low-slope roofs, from San Jose and Sunnyvale to Palo Alto, Los Gatos and Gilroy. That matters most for Eichler and other low-slope roofs, where the low-slope standard is much stricter than the steep-slope one.
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
Do cool roofs have to be white?
No. Many shingles and tiles in medium and dark colors carry cool-roof ratings.
Who checks cool-roof compliance?
The building inspector at final, using the product documentation.
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.