Short answerIf you replace more than half of your roof in most of the Antelope Valley, California's energy code requires the new roofing to reflect a minimum amount of sun. For a steep roof in climate zone 14 that is an aged solar reflectance of 0.20 and thermal emittance of 0.75, or an SRI of 16. There are exceptions, and one of them matters for tile.
When does the cool roof rule apply to a reroof?
When more than 50 percent of the roof is replaced, including a new layer laid over the old one, under a permit applied for on or after January 1, 2026.
The 2025 Energy Code governs permits applied for from January 1, 2026. A small repair stays under the line; a full reroof is over it.
Sources: California Energy Commission, 2025 Energy Code; California Energy Commission, 2025 Building Energy Efficiency Standards, Section 150.2(b). Checked October 18, 2026.
What are the cool roof numbers for a steep roof?
In climate zones 4 and 8 through 15, new steep-slope roofing needs an aged solar reflectance of at least 0.20 and a thermal emittance of at least 0.75, or an SRI of at least 16.
Low-slope roofs have a much higher bar: an aged reflectance of 0.63 and emittance of 0.75, or an SRI of 75, in zones 4 and 6 through 15. Palmdale's cool roof sheet places the city in zone 14 and asks for products labelled by the Cool Roof Rating Council, which is where those numbers are printed.
Sources: California Energy Commission, 2025 Building Energy Efficiency Standards, Section 150.2(b); City of Palmdale, Title 24 Roofing Requirements. Checked October 18, 2026.
Are there exceptions to the cool roof rule?
Yes. A steep reroof counts as meeting the rule when the ceiling has at least R-38 insulation, and roof constructions weighing at least 25 pounds per square foot are exempt from the reflectance minimums.
The weight exception is the one to ask about with tile. Ask what the tile you are choosing weighs per square foot, as installed, before you rule out a colour. The insulation exception means an attic that is already well insulated can open up colour choices too.
Sources: California Energy Commission, 2025 Building Energy Efficiency Standards, Section 150.2(b). Checked October 18, 2026.
Is every town we serve in climate zone 14?
No. On the Energy Commission's ZIP list, most of the valley's ZIPs are zone 14, but 93561 in Tehachapi and 91390 in Agua Dulce are zone 16, where the steep-slope minimum does not apply.
A building department can assign one zone to a ZIP that crosses two, so the zone for a specific address is worth confirming. Most of our town pages list the zone a local ZIP shows on the list.
Sources: California Energy Commission, Building Climate Zones by ZIP Code. Checked October 18, 2026.