Quick answer
San Diego projects are reviewed under the 2025 California Building Standards Code, which applies to all applications submitted since January 1, 2026. The City of San Diego’s Development Services Department handles city addresses, and the County handles unincorporated areas. Seismic design, coastal zone rules, fire hazard areas and hillside soils are the local issues that most often require an engineer.
San Diego has strong demand for ADUs, additions and rebuilds, along with some of the most varied site conditions in the state, from coastal bluffs to canyon edges and fire-prone hillsides.
Which codes apply
California updates its codes every three years. The 2025 California Building Code and California Residential Code, based on the 2024 International Codes, apply to permit applications submitted on or after January 1, 2026. A state law has also paused new residential building standards until June 2031, so these residential rules are expected to remain stable for several years.
Who reviews your permit
City of San Diego addresses go to the city’s Development Services Department. Unincorporated areas go to the County, and other cities in the county, such as Chula Vista, Oceanside or Carlsbad, each have their own building departments. Confirm the jurisdiction from your address first.
Local issues that need engineering
- Seismic design: additions, second stories, large openings and ADUs need lateral bracing designed for earthquake forces.
- Coastal zone: projects in the coastal zone may need a coastal development permit in addition to the building permit, which adds time and review.
- Fire hazard areas: hillside and canyon lots often fall under wildland-urban interface requirements for ignition-resistant construction and vegetation management.
- Hillsides and canyons: slopes, retaining walls and foundations near canyon edges frequently need a geotechnical report and engineered foundations.
ADUs in San Diego
ADUs remain one of the most common permits here. Detached units, garage conversions and units over garages each have different structural and fire separation needs. See our ADU engineering guide.
Cost and turnaround
Fixed fees: review and stamp from $249, engineered plans from $599, multi-discipline packages from $1,999. See our California engineering page.
What to send us
- Property address
- Survey, floor plans or a sketch
- Geotechnical report for hillside or canyon lots, if available
- Any comments from Development Services
Common questions
Which California code applies to my San Diego project?
Applications submitted on or after January 1, 2026 follow the 2025 California codes. Earlier applications stay under the 2022 codes.
Do I need a coastal development permit?
Possibly, if your property is in the coastal zone. Check the coastal zone map for your address before design starts.
Does an ADU need a structural engineer in San Diego?
Most do, for lateral bracing, foundations and any conversion of an existing garage or structure.
Does my engineer need a California license?
Yes. Sealed drawings for California projects must come from an engineer licensed in California.