The short version
In short: When you replace more than half of a sloped roof in most of our service area, including Calabasas, Agoura Hills, Hidden Hills, and the west San Fernando Valley (Climate Zone 9), California’s Energy Code requires a cool-rated roofing product: an aged solar reflectance of at least 0.20 and thermal emittance of at least 0.75, or an SRI of at least 16, rated by the Cool Roof Rating Council. Flat and low-slope roofs need far higher ratings, in more climate zones. City of Los Angeles neighborhoods also follow the city’s own cool roof rule. Repairs don’t trigger it.
More than half replaced
The rules apply to reroofs, not to repairs or small sections.
Slope matters
Sloped roofs have a modest minimum. Flat roofs need near-white surfaces.
So does your zone
Most of our area is Climate Zone 9. Coastal Malibu is Zone 6.
Los Angeles adds its own
LADBS checks the cool roof product on reroofs in City of LA neighborhoods.
What counts as a cool roof
A cool roof reflects more sunlight and gives off absorbed heat faster than a standard roof, which keeps the roof surface and attic cooler. The code measures two things:
- Solar reflectance: how much sunlight the surface reflects, from 0 to 1. The code uses the aged value, measured after three years of weathering.
- Thermal emittance: how well the surface releases the heat it does absorb, also from 0 to 1.
- Solar Reflectance Index (SRI): one number that combines both. The code accepts either the SRI or the two separate values.
Only products tested and labeled by the Cool Roof Rating Council (CRRC) count. The CRRC publishes the ratings in its online product directory.
California’s rule: Title 24 minimums for reroofs
California’s Energy Code (Title 24, Part 6) sets the statewide rule. For homes, it applies when more than half of the roof is replaced or covered with a new layer. The 2025 code, in effect since January 1, 2026, keeps the same single-family values as the 2022 code:
| Roof | Climate zones | Minimum (aged) |
|---|---|---|
| Sloped (2:12 pitch or steeper) | Zones 4 and 8–15 | Solar reflectance 0.20 and thermal emittance 0.75, or SRI 16 |
| Flat or low-slope (under 2:12) | Zones 4 and 6–15 | Solar reflectance 0.63 and thermal emittance 0.75, or SRI 75 |
Exceptions. The roof area under building-integrated solar panels is exempt, and so are very heavy roofs (at least 25 lb per square foot). For sloped roofs, the Energy Commission’s compliance forms list other options. Depending on the climate zone, these include high attic insulation, a radiant barrier, or no ducts in the attic. We check which ones fit your home during the inspection.
Which climate zone is your home in?
California has 16 building climate zones, set by the Energy Commission and looked up by address or ZIP code. In our area:
- Climate Zone 9: Calabasas, Hidden Hills, Agoura Hills, and Woodland Hills appear in Zone 9 in the Energy Commission’s ZIP code tables, as does most of the west San Fernando Valley. The sloped-roof rule applies.
- Climate Zone 6: Coastal Malibu. The state’s sloped-roof rule doesn’t apply in Zone 6, but the flat-roof rule does.
- Everywhere else: Zone lines don’t follow city limits, and some ZIP codes cross two zones, so we confirm the zone for your exact address.
City and county rules on top of the state’s
City of Los Angeles (Encino, Tarzana, Woodland Hills, West Hills, Canoga Park, Winnetka, Reseda, Northridge, and Chatsworth). The Los Angeles Green Building Code requires a CRRC-labeled cool roof product when more than 50% of a home’s roof is replaced. Its listed exceptions include roof repairs, replacing 50% or less of the roof, roofs where solar systems are being installed, and roofs weighing at least 25 lb per square foot. LADBS’s current plan-check sheets list higher targets than the state’s for some roofs, so we check the values that apply to your reroof when we pull the permit.
Calabasas. We found no separate city cool roof ordinance. The state rule applies, and the city’s reroof handout says that when more than half the roof is replaced, the whole roof must meet current code. A reroof permit is required first, and roofing must be Class A. See our Calabasas roof permit guide.
Malibu. The city’s re-roof policy requires Cool Roof Rating Council compliant products, in addition to Class A materials.
Unincorporated Los Angeles County (such as Topanga). The county’s Green Building Standards Code (Title 31) adds cool roof standards for new buildings and for alterations, so we confirm the requirements with LA County Public Works for each project.
Cool doesn’t have to mean white
On a sloped roof, the 0.20 minimum is within reach of many standard colors. Cool-rated shingles and concrete and clay tile come in grays, tans, browns, and terra cotta, using pigments that reflect the sun’s infrared light. That makes it easier to match your neighborhood and HOA color rules. Flat roofs are different: 0.63 usually means a white or light-colored membrane such as TPO, or a reflective coating.
In fire zones, the roof also has to be Class A. Many cool-rated products are part of Class A assemblies, so you rarely have to choose. Our Class A fire-rated roofing guide explains the fire rules.
How it’s checked
- At permit.The permit application names the roofing product, and on reroofs that trigger the rule, a prescriptive alterations form shows how the roof complies.
- On the material.The product carries a CRRC label with its rated values.
- At final inspection.The installer signs a certificate of installation, and the inspector can check the label and paperwork against what’s on the roof.
How we handle it
During the free roof inspection, we measure the roof, note the slope of each section, and confirm your climate zone and which city or county issues the permit. Your written estimate names products that meet the cool roof rule, the fire rating, and your HOA guidelines where they apply, and we file the paperwork with the permit. See cool roofing for the products we install and roof replacement for what a full reroof includes.
Not sure your project triggers the rule?
Call (818) 351-2918. We’ll tell you whether it applies to your roof before you choose a color.
Frequently asked questions
Does a roof repair trigger the cool roof rules?
Usually not. California’s Energy Code and the City of Los Angeles apply their cool roof rules when more than half of the roof is replaced. Repairs and smaller replacements don’t trigger them, although the work still needs a permit. See repair or replace.
Does a cool roof have to be white?
Not on a sloped roof. The state minimum for sloped roofs is low enough that many shingles and tiles in grays, tans, and earth tones qualify. Flat and low-slope roofs need much higher reflectance, which usually means a white or light-colored membrane or coating.
How do I find my home’s climate zone?
The California Energy Commission publishes a building climate zone map and a lookup by address or ZIP code. Most of Calabasas and the west San Fernando Valley is in Climate Zone 9, and coastal Malibu is in Climate Zone 6. We confirm the zone for your address before we write your estimate.
Can a cool roof also be Class A fire-rated?
Yes. Many cool-rated shingles, concrete and clay tiles, and membranes are also part of Class A roof assemblies, which Calabasas and other Very High Fire Hazard Severity Zones require. We choose products that meet both rules.
Sources
California Energy Commission, 2025 Prescriptive Residential Alterations form (CF1R-ALT-01-E) and 2025 Single-Family Residential Compliance Manual, Chapter 9; California Energy Commission, California Building Climate Zones map; Cool Roof Rating Council, California Energy Code (Title 24); Los Angeles Department of Building and Safety, Cool Roof fact sheet and City of Los Angeles Ordinance No. 187208; City of Calabasas Building & Safety, “Roof Repair, Replacement & Covering” handout; County of Los Angeles, cool roof amendment to Title 31. Requirements change, so we confirm current rules on every project. This guide is general information, not engineering advice.