Barn With Carport: Types, How They Compare, Permit and Cost

What does "barn" mean in a barn with a carport search?

In a US carport search, barn means a barn-style carport, a pole barn or a farm barn.

Wikipedia describes a carport as “a covered structure used to offer limited protection to vehicles, primarily cars, from rain and snow”.

carport.com defines a metal barn as: “A prefabricated steel agricultural building: typically a clear center span with one or two lean-tos”.

The diagram defines the barn-style carport by roof look and sides, the pole barn by post-frame construction and the farm barn by farm use.

Where does a carport end and a barn begin?

Alan's Factory Outlet states in a help article dated 2023-10-01: “When you add side-panels to enclose a carport, it becomes a metal building.” The City of San Diego, in Information Bulletin 205 (August 2022), requires a carport to be entirely open on two or more sides except for structural supports. It also requires a building permit to enclose an existing carport.

California Building Code Section 312.1 lists carports in Group U, the utility and miscellaneous group. Alan's and San Diego both treat enclosure as the dividing line.

Which should you choose for your property?

Choose a carport to park under, a barn-style carport for the barn look, and a pole barn for a post-frame building.

When do you need a permit for a barn or a carport?

The US model code exempts one-story detached accessory structures up to 200 square feet; local lines differ.

Last verified: October 2026

Permit lines in square feet: California 120, IBC tool and storage sheds 120, model code 200 and Virginia 256. A 12x20 plan is over three of the four lines; a 20x20 and a 42x25 are over all four.

This page provides general information about permit and code requirements based on publicly available sources cited above. Building codes and permit requirements vary by jurisdiction and change over time. This is not a substitute for confirming current requirements with your local building department or consulting a licensed contractor or engineer for your specific project.

What does the model code say?

International Residential Code R105.2 (2021 edition, as printed by Grant County, WA) exempts one-story detached accessory structures up to 200 square feet of floor area. The City of Tacoma quotes an International Building Code exemption at 120 square feet for tool and storage sheds (modified 2025-09-22).

Portland exempts detached carports of 200 square feet or less, measured under the roof at the drip line, and a zoning permit is still required (revised 2024-03-08).

What do California and Virginia say?

The 2022 California Residential Code sets 120 square feet (El Dorado County document). Virginia's Uniform Statewide Building Code Section 108 sets 256 square feet for tool and storage sheds.

The 600 square foot figure that some guides print is a frost-footing figure, not a permit exemption (permitsguide.com, March 2026).

How does a farm-barn exemption work?

Oregon's Building Codes Division form 440-2654 (05/22) applies ORS 455.315. An exempt agricultural building cannot be a dwelling, cannot hold 10 or more persons at once (other than for growing plants) and cannot be used by the public.

Electrical, mechanical, boiler, plumbing and septic permits still apply, and other states differ.

Agricultural exemptions differ by state and by use. Confirm the rule with your state or local building department.

Barn with carport: common questions

Six questions cover permits, pole barns, barn-style carports, conversion, cost and horse shelters.