Every newly constructed detached ADU in Imperial County, California must include a Title 24-compliant solar PV system. Imperial County spans climate zone 15, which determines exactly how many kilowatts your specific project must install for code compliance.
Local building departments across Imperial County enforce Title 24 at plan check. Plans submitted without a properly sized solar system are routinely rejected unless a documented exemption (shading, roof area, structural) applies.
Imperial County has the highest solar irradiance in California, making it one of the best places for solar energy production. ADU solar systems here produce exceptional output year-round. IID provides electricity to most of the county.
Title 24 multiplies your ADU's conditioned floor area by a climate-zone-specific kW factor. Across Imperial County's climate zone 15, most ADUs land in the 1.6–4.0 kW range — typically 4 to 10 modern (~400W) panels.
Title 24-compliant ADU solar packages range from $4,000 (Standard cash) to $15,000+ (Premium with battery) across Imperial County. HDM financing typically reduces effective cost by ~40% via commercial ITC pass-through. Main utilities serving the county: IID.
Yes. Title 24 is California state law and every jurisdiction in Imperial County enforces it at permit submittal.
Imperial County sits in climate zone 15. Use our cost calculator to map your exact ZIP code to its Title 24 climate zone.
Exemptions are project-specific, not countywide. The most common are shading (<70% annual solar access), insufficient roof area, and structural infeasibility. Your designer documents these on the CF1R compliance form.