California Title 24 Part 6 energy standards require cool roof reflectivity for most new and replacement low-slope roofs in Orange County's climate zones 6, 8, and 10, covering all cities and unincorporated areas.
Title 24 prescriptive paths require minimum aged solar reflectance and thermal emittance values for low-slope roofs and, in steep-slope residential applications, certain reflectance thresholds depending on climate zone. Orange County spans climate zones 6 (coast), 8 (inland), and 10 (foothills), each with calibrated requirements. Roof replacements above 50 percent of total roof area generally trigger compliance. Cool roof rating council certification is required to demonstrate eligible product values. Orange County Building Inspection enforces compliance in unincorporated areas through plan check and roof permit closeout inspections.
Installing a noncompliant roof can trigger plan-check rejection, failed final inspection, required tear-off, and Title 24 documentation penalties.
See how other cities in Orange County handle cool roof requirements.
See how Costa Mesa's cool roof requirements rules stack up against other locations.
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