California

California Permit Guide for Metal Carports, Garages and Barns

In most of California, a metal carport or garage needs a building permit from your city or county, because the state's residential code only exempts one-story detached accessory structures up to 120 square feet of floor area. Even a small single carport is usually well past that size, so plan on applying. California runs one statewide code, the California Building Standards Code (Title 24), and the 2025 edition has applied to permit applications filed on or after January 1, 2026. Your local building department enforces it, and it can add stricter local amendments for things like snow, wind, wildfire or earthquake risk. Getting a California carport permit means talking to the city building department if you live inside city limits, or the county building division if you live in an unincorporated area. Farm buildings are handled county by county, and some counties offer an agricultural exemption with their own rules.

Building code in effect

California adopts one statewide code: the California Building Standards Code, published as Title 24 of the California Code of Regulations. The California Building Standards Commission lists the 2025 Triennial Edition of Title 24, published July 1, 2025, with an effective date of January 1, 2026. The Commission's Information Bulletin 25-01 says permit applications submitted on or after January 1, 2026 must comply with the 2025 code under Health and Safety Code Section 18938.5, while applications received on or before December 31, 2025 stay under the 2022 code. Homes and their accessory buildings fall under Part 2.5, the 2025 California Residential Code, and other buildings fall under Part 2, the 2025 California Building Code. The 2025 set also includes Part 7, the California Wildland-Urban Interface Code, along with electrical, mechanical, plumbing, energy, fire and green building parts. Cities and counties may amend Title 24 with more restrictive local rules, but each amendment has to be ratified and filed with the state for every triennial edition before it takes effect.

Who issues permits

Permits are issued locally, not by a state office. If your property is inside an incorporated city, the city's building department reviews the plans and does the inspections. In unincorporated areas, the county building division or planning and building department handles it, and California has 58 counties, each with its own fees, forms and portal. The Building Standards Commission's bulletin points to Health and Safety Code sections such as 17960, 18938 and 18941.5 for local enforcement responsibility, and the Department of Housing and Community Development (HCD) sets the residential standards that local departments enforce. HCD notes that the permit application date, which decides which code edition applies, is generally set by the local government. Zoning and setback approval usually comes from the same city or county, often through its planning division.

County permit guides

County guides are coming soon.

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When you need a permit

Carports: A carport is a detached accessory structure, and the 2025 California Residential Code Section R105.2 only exempts one-story detached accessory structures up to 120 square feet of floor area. A common 12 by 20 foot carport is 240 square feet, double the exempt size, so expect to need a building permit.
Garages and enclosed buildings: An enclosed metal garage or workshop needs a building permit, plan review and inspections. Electrical work such as lights or outlets is reviewed under the California Electrical Code, which is part of Title 24.
Small storage sheds: A one-story detached shed with no more than 120 square feet of floor area is exempt from a building permit under CRC Section R105.2, as published by local departments like the City of Lathrop. The exemption doesn't apply to storm shelters, and zoning setbacks still apply.
Local changes to the exempt size: Cities and counties can amend the administrative sections of Title 24 by local ordinance, and some change the list of exempt work. Ask your building department whether it uses the 120 square foot limit as written.
Farm and ranch buildings: There is no automatic statewide farm exemption. Some counties run an agricultural exemption program with acreage, zoning and setback rules, and electrical, plumbing and mechanical work usually still needs a permit.

Farm buildings

California doesn't have a blanket state law that frees farm buildings from permits. Barns and similar buildings are classified under the California Building Code as Group U agricultural buildings, defined in Section 202 as structures built to house farm implements, hay, grain, poultry or livestock, and not used for living, public use or processing work. Appendix C of the California Building Code covers Group U agricultural buildings, and counties that want an exemption adopt it or write their own rule by local ordinance under Health and Safety Code sections 17958.5, 17958.7 and 18941.5. The programs differ a lot. Sonoma County requires at least five acres, an application with plans, and a 60 foot setback from property lines in most cases, while Amador County amends Appendix C Section C101.1 and still requires separate electrical and plumbing permits. Lassen County's application says electrical, plumbing and mechanical work is not exempt, and exempt buildings must still meet zoning setbacks. If you're buying a barn or hay cover, ask your county building office whether it has an ag exemption and what paperwork it takes.

Wind and snow

Earthquakes are the big structural concern across most of California, and the state's codes are written with seismic design in mind. The California Geological Survey maps active faults under the Alquist-Priolo Earthquake Fault Zoning Act, which bars structures for human occupancy from being placed over an active fault, and its EQ Zapp tool lets you look up an address for fault, liquefaction and landslide zones. Snow load matters in the mountains, and some counties set their own numbers; Siskiyou County, for example, works with a 40 PSF minimum flat roof snow load in parts of its unincorporated area. Wildfire is another factor, since the 2025 Title 24 includes the California Wildland-Urban Interface Code as Part 7. Your local building department will tell you the wind, snow and seismic design values your engineered drawings need to meet. Our partnered manufacturers offer certified buildings rated for 140 MPH wind and 35 PSF snow load, and higher ratings can be quoted where required.

Before you order

Find out whether your lot is inside city limits or in an unincorporated county area, since that decides which building department reviews your permit.
Ask the building department for the wind speed, snow load and seismic values it requires, and order engineered drawings that meet them.
Check zoning setbacks and any HOA rules before you pick a size and spot, and look up your address in the state's EQ Zapp tool for fault or landslide zones.
If the building is for farm use, ask the county whether it offers an agricultural exemption and what acreage, setback and electrical permit rules come with it.

Common questions

Do I need a permit for a carport in California?
Usually, yes. The 2025 California Residential Code only exempts one-story detached accessory structures up to 120 square feet, and most carports are larger than that. Apply with your city building department, or the county if you're in an unincorporated area.

Do I need a permit for a metal garage in California?
Yes. An enclosed metal garage is a building under Title 24 and needs a local building permit, plan review and inspections. Any wiring for lights or outlets is covered by the California Electrical Code and is inspected too.

Are farm buildings exempt in California?
Not automatically. Some counties, such as Sonoma, Amador and Lassen, offer an agricultural exemption by local ordinance with conditions like minimum acreage and setbacks, and electrical and plumbing work usually still needs a permit. Ask your county building office if it has a program.

Which code edition applies to my project?
The 2025 California Building Standards Code applies to permit applications submitted on or after January 1, 2026. Applications received on or before December 31, 2025 stay under the 2022 code.

Sources

Permit rules change. Always confirm with your local permit office before you build.

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