California Title 24 Building Energy Efficiency Standards mandate cool-roof reflectance values for new and re-roofed buildings in San Bernardino County climate zones 10, 14, 15, and 16, covering desert and mountain communities prone to extreme heat.
Title 24 prescribes minimum solar reflectance and thermal emittance values that vary by climate zone and roof slope. San Bernardino County spans climate zones 10 (Inland Empire valleys), 14 (high desert including Victorville and Hesperia), 15 (low desert near Joshua Tree and Twentynine Palms), and 16 (mountain communities). Low-sloped roof replacements over 50 percent of total area trigger compliance. Cool roof products carry Cool Roof Rating Council labels. Building permits must show compliance documentation. The standards reduce summer cooling loads, peak grid demand, and urban heat island effects in dense logistics corridors.
Building permit denial for noncompliant roofing. Re-roofing without permits triggers stop-work orders, double permit fees, and possible removal at owner expense.
See how Rancho Cucamonga's heat island mitigation rules stack up against other locations.
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