California's Energy Code sets surface values for roofs that are replaced, and Los Angeles layers its own values on top. The values are numbers on a product label, not a color.
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Reflectance, emittance and SRI
Aged solar reflectance measures how much sunlight a surface still returns after weathering. Thermal emittance measures how quickly the surface sheds the heat it takes in. The Solar Reflectance Index, or SRI, combines the two into one score.
The CRRC, an independent testing body, keeps a directory of tested products. The label and the directory entry show the aged values. A product can meet the rule either by its reflectance and emittance together, or by its SRI.
A light color is not proof. Ask for the CRRC listing number, and check it against the values below.
Color is only part of it. Dark tile and dark metal can be cool-rated through their finish, and a pale shingle may fail if it was never tested. Only the listing settles it.
When the rule is triggered
On a single-family house, the state rule takes hold when a job replaces over 50 percent of the roof, and an overlay is counted the same way. Repairs and jobs of half the roof or less sit outside it.
For steep slopes, zone 4 and zones 8 to 15 call for 0.20 for aged reflectance and 0.75 for emittance, or SRI 16 instead. For low slopes, zone 4 and zones 6 to 15 call for 0.63 and 0.75 together, or SRI 75 alone.
The 2025 Energy Code, in force since 1 January 2026, keeps this rule as it was. The California Energy Commission reported in 2025 that Executive Order N-29-25 lifts some of the update's requirements for houses lost in the 2025 Los Angeles fires, so an owner who is rebuilding should ask the building department which parts apply.
Because half the roof or less is exempt, a plan that splits one roof into two phases inside a year gets a second look. In the City of Los Angeles, once over half a roof is redone inside one year, the whole roof must meet current code.
What to ask for on a cool roof
- The CRRC listing number for the exact product
- Aged reflectance and emittance on the listing
- Which path applies: state rule, City values or an exception
- Whether more than half the roof is being replaced
- How solar panels change the area covered
- Documents the permit requires at inspection
When this page matters to you
- A job that replaces over half of a house roof
- A permit comment asking for cool roof evidence
- A product label with no aged values
- A bid claiming tile profile avoids the rule
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City of Los Angeles values and exceptions
The Los Angeles Green Building Code has had a residential cool roof requirement, for jobs that replace more than half the roof, in full effect since 1 January 2015. For steep slopes the City asks for 0.25 aged reflectance and 0.85 emittance, or SRI 20. Low slopes need 0.65 and 0.85, or an SRI of 78 (LADWP, 2022). Replacing half the roof or less, or roofs with solar installed, are outside it.
The state lists its own exceptions: an R-38 ceiling, a radiant barrier not over spaced sheathing, ductwork kept out of the attic in certain zones, or added continuous insulation. It also leaves out roof area under solar panels and any roof of 25 pounds per square foot or more.
Tile profile, raised battens and the air under a tile are not on that list.
Options by roof type
Shingles: cool-rated lines in light and medium colors carry CRRC listings. Tile: cool-rated concrete and clay tile exist, in fired and coated finishes. Metal: factory finishes reach the steep-slope values readily. Low-slope roofs: white single-ply membranes and reflective coatings.
Does it help? Climate zones 9 and 14 are hot inland zones where cooling load is high, and a reflective roof reduces heat gain through the ceiling. Zone 6 on the coast has a milder cooling load, and the state rule covers low-slope roofs there but not steep ones.
Savings figures depend on insulation, ducts and use. Ask us for the listing and check the label.
Solar panels change the arithmetic. Roof area under panels is outside the state rule, so on a roof that will carry a large array the area that needs a cool-rated covering may be smaller. Raise it in the assessment before ordering.
Cool roof questions
What do reflectance, emittance and SRI mean?
Reflectance measures how much sunlight an aged surface sends back. Emittance is how readily it releases absorbed heat. SRI is a single score that combines them. A product can meet the rule by reflectance and emittance together or by SRI.
Which reroofs does the state cool roof rule reach?
Single-family jobs that cover more than half the roof, with an overlay counted as a replacement. Steep roofs fall under the rule in zone 4 and zones 8 to 15; for low slopes, zones 6 to 15 and zone 4 apply.
What cool options exist for tile, shingle and flat roofs?
Cool-rated shingles, cool-rated concrete and clay tile, factory-finished metal, and white single-ply membranes or reflective coatings for low slopes. Each product has a CRRC listing with aged values.
Is a cool roof worth it in zones 9 and 14, the hot inland ones?
Cooling loads run high there, and a reflective roof reduces heat entering through the ceiling. Savings turn on the insulation, the ducts and the way the house is used.
How do I check a product's CRRC listing?
Look the product up in the CRRC directory, where its entry shows the aged values for reflectance and emittance. Compare them to the values for your slope and zone. Ask us for the listing number before ordering.