Missouri

Missouri Permit Guide for Metal Carports, Garages and Barns

Whether you need a permit for a carport in Missouri depends on your county or city, because the state has no statewide building code for houses, garages or barns. Each county and city decides for itself, so the rules can change a lot from one side of a county line to the other. Missouri has 114 counties plus the independent City of St. Louis. Plenty of rural counties have no building code at all, while cities and the bigger counties around Kansas City, St. Louis and Springfield run full permit programs.

Building code in effect

There is no state-adopted residential or general building code in Missouri. Codes are local option. The U.S. Department of Energy lists Missouri's code status as home rule with enforcement by each jurisdiction. Under RSMo 64.170, a first or second class county that had not adopted a building code before August 28, 2001 can't adopt one unless voters in the unincorporated area approve it at an election. Towns adopt their own codes. Where a code is in place, it is usually some edition of the International Residential or Building Code, but the edition depends on the local government, so ask.

Who issues permits

If you live inside city limits, the city usually handles building permits. In unincorporated areas, it's the county, but only if that county has adopted a building code. Many rural counties have no building permit at all. Even in a county without a building code, you may still run into county zoning, floodplain permits, septic rules or road setbacks, and those are handled separately from building permits.

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

No code, no building permit: In a county with no adopted building code, there is no county building permit for a garage or carport in the unincorporated area. Zoning and floodplain rules may still apply.
Farm structures in county zoning: RSMo 64.090 and 64.620 say county zoning and building restrictions under those sections do not apply to farm buildings or farm structures used for farming, as long as they are not in the mapped flood hazard area.
Inside city limits: These county rules don't reach incorporated areas. A city sets its own permit rules, and most cities require a permit for a detached garage.
Carports and sheds: Size cutoffs for small sheds and carports are set locally. Many places that use the IRC exempt small one-story accessory buildings below a set floor area, but check your own city or county.

Farm buildings

Missouri has no single statewide farm building exemption from a state code, because there is no state code. The farm rule shows up in the county planning and zoning statutes. RSMo 64.090 (first class charter counties) and RSMo 64.620 (second and third class counties that have adopted county planning) say those sections do not apply to the raising of crops, livestock, orchards or forestry, or to the erection, maintenance, repair, alteration or extension of farm buildings or farm structures used for farming, outside the area shown on the flood hazard area map. If your barn sits in a mapped floodplain, expect floodplain rules. Cities set their own rules for any farm ground inside city limits.

Wind and snow

Missouri is an inland state, so hurricane winds are not the issue, but tornadoes and strong thunderstorm winds are common statewide. Snow loads run higher in the northern counties than in the Bootheel and the far south. Ice storms also hit parts of the state. Since many counties have no code, nobody may tell you what to design for, so it pays to ask your county or city what wind speed and snow load they use, or what your lender or insurer wants. 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

First find out if your lot is inside city limits or in the unincorporated county. That decides who you call.
Ask the county if it has adopted a building code. If not, ask about zoning, floodplain and road setbacks anyway.
Check the FEMA flood map for your lot, since Missouri's farm exemption in county zoning law does not cover the flood hazard area.
Even with no permit required, keep the engineered drawings. Lenders, insurers and future buyers may ask for them.

Common questions

Do I need a permit for a carport in Missouri?
It depends on where you live. Missouri has no statewide code. Many rural counties have no building permit at all, while cities and larger counties often do. Call your city or county before you order.

Do I need a permit for a metal garage in Missouri?
Inside most city limits, yes. In unincorporated areas, only if your county has adopted a building code, and since 2001 a first or second class county needs voter approval to adopt one (RSMo 64.170). Zoning or floodplain permits may still apply.

Are farm buildings exempt?
Under RSMo 64.090 and 64.620, county zoning and building restrictions under those laws do not apply to farm buildings used for farming, unless the building is in the mapped flood hazard area. Cities set their own rules.

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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