LA County Code Title 31 Green Building Standards and Title 26 Building Code adopt CALGreen Title 24 Part 11 baseline requiring cool roofing on new construction and major reroofs in unincorporated areas. Reflective materials must meet minimum solar reflectance and thermal emittance ratings.
LA County Code Title 31 (Green Building Standards) and Title 26 (Building Code) incorporate CALGreen Title 24 Part 11 and Title 24 Part 6 (Energy Code) requirements for cool roofing on new construction and reroofs in unincorporated areas. Low-sloped roofs (slope less than 2:12) typically must achieve a minimum 3-year aged solar reflectance of 0.55 and thermal emittance of 0.75, while steep-sloped roofs in CEC Climate Zone 9, 10, 14, 15, or 16 (most of LA County) must hit at least 0.20 aged solar reflectance. Building and Safety enforces during plan-check. Title 31 layers additional optional CALGreen Tier 1 and Tier 2 measures the Board encourages in heat-vulnerable communities.
Permits are denied for plans that fail Title 24 cool-roof requirements. Installation of non-compliant materials triggers correction notices, removal, and replacement at owner cost. Repeat contractor violations risk license referral to the Contractors State License Board.
See how Downey's cool roof requirements rules stack up against other locations.
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