If you pull a re-roof permit in the City of Los Angeles, there’s a good chance the law has opinions about your roof’s color, or more precisely, its reflectivity. Two overlapping rules apply: California’s Title 24 energy code, which sets solar reflectance and thermal emittance minimums for roofing in this climate zone, and LA’s own cool-roof ordinance, which extends similar requirements to most residential re-roofing in the city. The practical translation: many LA homeowners can no longer replace a dark conventional roof with another one, and the products that comply are the subject of this page.
What the rules actually measure
A cool roof is defined by two numbers. Solar reflectance is the share of sunlight bounced away instead of absorbed. Thermal emittance is how readily the surface sheds the heat it does absorb. Products are tested and listed with both values, and compliance means clearing the thresholds for your roof type, with steep-slope and low-slope roofs held to different standards. Your contractor’s permit paperwork cites the listed values; a homeowner never has to calculate anything, but knowing the vocabulary keeps a bid review honest.
What complies, material by material
- Asphalt shingles. Standard dark shingles usually fail; cool-rated lines with reflective granules pass, in colors far beyond white, including grays and browns that look entirely conventional. Expect a modest material bump over commodity shingles, detailed in our asphalt guide.
- TPO and flat systems. White TPO passes effortlessly, one reason for its LA takeover, per the TPO guide. Torch down complies via reflective cap sheets or coatings.
- Tile. Many clay and concrete profiles meet requirements through color choice and the natural ventilation of the profile, and lighter blends sail through.
- Metal. Factory reflective finishes are the easy case, covered in the metal guide.
What it costs you, honestly
Less than the reputation suggests. Cool-rated shingles and cap sheets carry single-digit-percentage premiums over their conventional twins, and for membrane and metal roofs compliance is often free because the standard product already qualifies. Set against LA cooling bills, the delta frequently pays itself back, which is the rare case of a mandate aligned with self-interest.
Three misconceptions to retire
- “Cool means white.” Rated products exist across the color range; the granule and pigment technology does the work, not the shade.
- “It only applies to new construction.” Re-roofs are exactly what the LA ordinance targets, with limited repair-size exemptions.
- “A low bid can skip it.” The inspector will not, and correcting a non-compliant roof after installation is the most expensive way to comply.
If a quote doesn’t mention cool-roof compliance at all, ask which listed product it assumes. The answer sorts contractors who pull permits from contractors who hope you won’t.
For how these rules tilt the material choice itself, start with the materials decision guide.
Figures on this page are informational estimates based on regional pricing data and automated roof measurements. They are not quotes or bids. Actual pricing requires an on-site inspection by a licensed contractor.