Wisconsin

Wisconsin Permit Guide for Metal Carports, Garages and Barns

Whether you need a carport permit in Wisconsin is mostly a local question, because the statewide home code, the Uniform Dwelling Code, covers houses but not detached garages or accessory buildings. Your city, village, town or county decides whether you need a building permit, a zoning permit, or both. If your lot is near a lake or river, county shoreland zoning adds its own setback and permit rules.

Building code in effect

Homes are built to the Wisconsin Uniform Dwelling Code (UDC), chapters SPS 320 to 325. It covers one- and two-family dwellings built since June 1, 1980, plus their additions and alterations. The state says plainly that the UDC does not cover detached garages or accessory buildings, so local ordinances fill that gap. A garage attached to the house (sharing a roof, floor or foundation, or tied in with a roofed breezeway) becomes part of the dwelling and falls under the UDC. Buildings used for business or other public uses fall under the Wisconsin Commercial Building Code, SPS 361 to 366. Its upgrade to the 2021 International Building Code with Wisconsin changes took effect September 1, 2025, replacing the 2015 edition. Commercial plans submitted to the state from October 1, 2025 on must meet the new code.

Who issues permits

Building permits are local. The UDC is enforced mainly by state-certified municipal or county building inspectors, and where a municipality does not enforce it, a county or a state-contracted inspection agency may. For a detached garage or carport, the permit (if any) comes from your city, village or town, or from the county if it handles building or zoning permits for your town. Zoning is a separate layer. Cities and villages zone inside their limits, and county general zoning applies in a town only if the town adopts the county ordinance. Counties must run shoreland zoning in all unincorporated areas, so a lake lot may need a county shoreland permit even if your town also issues a building permit.

County permit guides

County guides are coming soon.

Don't see your county? Call 919-725-8176 and we'll help you find the right office.

When you need a permit

Detached garages and carports: Not covered by the state Uniform Dwelling Code. Whether you need a permit, and at what size, is set by your city, village, town or county ordinance. Many still require a building or zoning permit, so call before you order.
Attached garages: A garage that shares a roof, floor or foundation with the house, or connects with a roofed breezeway, is part of the dwelling under the UDC and goes through the regular home permit process.
Lake and river lots: In unincorporated shoreland areas (within 1,000 feet of a navigable lake, pond or flowage, or 300 feet of a navigable stream or the floodplain edge, whichever is greater), buildings must sit at least 75 feet back from the ordinary high-water mark, and the county shoreland ordinance applies.
Business buildings: A metal building used for a business, as a place of employment or open to the public is covered by the Wisconsin Commercial Building Code (SPS 361 to 366), which now follows the 2021 IBC.

Farm buildings

Wisconsin's Commercial Building Code does not apply to buildings and structures on a farm premises used exclusively for farming purposes (SPS 361.02(3)(e)). Public use has to be limited to customers buying farm products, and at least 90 percent of those products must be grown or produced on that farm. A barn used to store, process or sell products you didn't raise generally falls under the commercial code. Farm buildings are also outside the Uniform Dwelling Code. Local zoning and county shoreland rules can still apply to a farm building, so check setbacks with your town or county before you build.

Wind and snow

Snow loads in Wisconsin run heavier in the north, especially along Lake Superior's snow belt, than in the southern counties. Summer brings strong thunderstorms, straight-line winds and the occasional tornado statewide. Lake Michigan shoreline areas also see lake-driven wind and snow. Ask your local building office for the design wind speed and ground snow load they use for your address before you pick a building. 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

Call your town, village or city clerk first. Since the state home code skips detached garages, the local ordinance is what sets the permit and size rules.
If you're within 1,000 feet of a lake or 300 feet of a river or stream, check with the county zoning office about shoreland rules and the 75-foot setback.
Ask whether your town uses county zoning or its own. That decides who reviews setbacks and lot coverage.
If the building will be used for a business, ask whether it falls under the commercial code before you finalize the size.

Common questions

Do I need a permit for a carport in Wisconsin?
It depends on where you live. Wisconsin's Uniform Dwelling Code doesn't cover detached accessory structures, so your city, village, town or county ordinance decides. Many places require at least a zoning permit, and lake lots fall under county shoreland rules with a 75-foot setback from the water.

Do I need a permit for a metal garage in Wisconsin?
Usually some kind of local permit, but the rule comes from your municipality or county, not the state. A detached garage is outside the UDC. An attached garage counts as part of the house and goes through the regular UDC permit and inspection process.

Are farm buildings exempt?
Buildings on a farm used only for farming are exempt from the Wisconsin Commercial Building Code under SPS 361.02(3)(e), and they're outside the home code too. Local zoning and shoreland setbacks can still apply, so check with your town or county.

Sources

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

Looking at buildings? See our metal carports, metal garages and metal buildings.

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