California is divided into 16 official climate zones by the California Energy Commission. Each zone has its own Title 24 energy budget reflecting local temperature, humidity, and solar conditions.
What California climate zones are
The 16 climate zones are the framework the CEC uses to set energy budgets across the state's varied geography — from cool coastal areas and mild valleys to hot inland and desert regions and cold mountain areas. Your project's zone is assigned by its exact address, often by ZIP code.
Why climate zones matter for Title 24
Title 24 is a statewide code, but the energy budget your design must meet is calibrated to your climate zone. That means the same standards can require different envelope, HVAC, window, and solar choices depending on the zone — all determined when your address is modeled in CEC-approved software.
California Title 24 climate zones — your project's zone is set by its address. For the official map, see the California Energy Commission's climate zone resources.
How climate zones affect Title 24 reports
The zone influences the balance between heating, cooling, and solar gain in the energy model. Hotter zones tend to emphasize cooling, window SHGC, and solar; cooler and mountain zones emphasize insulation and heating performance. We handle this automatically based on your address.
Common project types affected
ADUs, garage conversions, new homes, residential remodels, and multifamily projects all follow Title 24 with the budget set by climate zone. Explore ADU, residential, and multifamily services.