Barndominium permitting is limited statewide; extra approvals or variances may be needed.
The California Building Standards Commission (CBSC) adopts and enforces the CBC statewide. Local jurisdictions may adopt more restrictive amendments but cannot be less restrictive than state code.
Primary Code
California Building Code (CBC)
Code Version
2022 CBC (based on 2021 IBC with CA amendments)
Adoption Level
Statewide
Statewide Enforcement
Yes
California has the most extensive plan review process in the country. Third-party plan review is available in some counties to expedite the process.
Residential
Required
Commercial
Required
Agricultural
Required
Size threshold: structures under 120 sq ft may be exempt.
Detached agricultural accessory structures under 120 sq ft without plumbing, electrical, or mechanical may be exempt. Agricultural buildings on bonafide farms may qualify for reduced requirements but are not fully exempt.
Detached accessory structures under 120 sq ft without utilities do not require a building permit, but a planning permit is still required.
Seismic design is the primary structural concern in California. AISC 341 ductile frames, oversized anchor bolts, and special connections required in high-seismic zones. Sierra Nevada has extreme snow loads.
Wind Load
85–110 mph
low zone
Snow Load
0–200+ psf (Sierra Nevada)
Seismic
C–F
Category
Flood
FEMA Regulated
Energy Code
California Title 24 Part 6
Version
2022 California Energy Code
California has the strictest energy code in the nation. Title 24 Part 6 requires detailed energy modeling and compliance documentation. Solar PV requirements for new residential construction.
License Type
Contractors State License Board (CSLB) license
Project Threshold
$500
All contractors must hold a CSLB license for projects over $500 including labor and materials. General contractor (Class B) license is most common. Exam, experience, and bond required.
Front
20–30 ft
Side
5–10 ft
Rear
15–25 ft
Setbacks vary significantly by jurisdiction and zone. Fire hazard zones may require increased setbacks and defensible space.
Seismic foundation design is critical. Soils reports typically required. Expansive soil mitigation often needed.
Requires full permits. Seismic engineering required. California Environmental Quality Act (CEQA) review may apply for larger projects.
Reduced requirements on bonafide agricultural land but not fully exempt. Must still meet structural code.
Extremely challenging in most California jurisdictions. Residential classification triggers full CBC compliance, Title 24, and CalGreen. Very few rural areas are feasible.
Full permits required. Seismic requirements apply. Solar-ready requirements for new residential.
Full CBC compliance with extensive plan review. ADA, fire sprinkler, and Title 24 compliance all required.
HOAs are very common throughout California. Metal building exteriors are almost universally prohibited by HOA CC&Rs in suburban developments.
Extensive flood zones in Central Valley, coastal areas, and along major rivers. Strict FEMA compliance required.
Verify the information above directly from these official sources. Regulations change — always confirm with your local building department before starting construction.
Disclaimer: This guide is for informational purposes only and does not constitute legal or professional advice. Building codes, permit requirements, and zoning regulations change frequently. Always verify current requirements with your local building department, planning office, or a licensed professional before starting construction. Homestead Steel Structures & Design is not a legal authority on building codes or zoning regulations. Last updated February 2026.
