San Diego County ranges from mild coastal zones to warmer inland valleys, with strong demand for ADU and residential energy compliance reports.
Title 24 Across San Diego County
ADUs are one of the most common permit types in the county, alongside additions, new single-family homes and small multifamily buildings. Each city — and the county itself for unincorporated areas — runs its own plan check, but the Title 24 energy code and forms are the same everywhere in California. Most homes and ADUs use a CF1R, prepared in CEC-approved software from your plans.
Coast, Mesas and Inland Valleys
Close to the ocean, summers are mild and heating and cooling loads are small, so projects often comply without major upgrades. Moving east across the mesas toward the inland valleys and foothills, summers get hotter and cooling, shading and window choices matter more.
Most of San Diego, along with Chula Vista, is in Climate Zone 7. Inland cities such as Escondido, El Cajon and Santee are in the warmer Climate Zone 10. The report always uses the zone set by your project address and ZIP code. Browse all zones on the climate zone map.
Common San Diego County Projects
- Detached and attached ADUs — see San Diego ADU Title 24 and whether ADUs need solar and energy compliance
- Coastal remodels and additions in North County cities such as Oceanside, Carlsbad and Encinitas
- Inland homes and additions in East County and inland North County, where cooling performance carries more weight
- Heat pump conversions replacing gas furnaces or water heaters — see the HVAC replacement service
For an overview of the wider region, see Southern California Title 24.
Frequently Asked Questions
Does a coastal San Diego ADU still need a Title 24 report?
Yes. A mild climate makes compliance easier, but a new ADU still needs energy documentation for the permit.
Which climate zone applies to my project?
The zone is assigned by address. We confirm it when we model your project, so you do not need to look it up first.
