How big a shed can you build without a permit?
We analyzed the building code in every U.S. state to find out where a backyard shed needs a permit — and where it doesn't.
The short answer
In much of the United States, you can legally build a backyard shed without pulling a building permit — but the size that stays exempt depends heavily on where you live.
The starting point is Section R105.2 of the International Residential Code (IRC), the model code that nearly every state builds its residential rules on. R105.2 exempts "one-story detached accessory structures" — the technical term for a shed — as long as the floor area stays at or under 200 square feet. (Before the 2009 edition of the IRC, the limit was only 120 square feet; it was raised because most prefabricated sheds on the market landed between the two.)
But "the United States" is really 50 separate rulebooks, and states amend that baseline. Some hold the 200-square-foot line. Others cut it down — to 144 in New York, 120 in California and Washington, and just 50 in the District of Columbia. A few go the other way, up to 256 in Virginia or 1,000 in Pennsylvania. North Carolina drops the area test entirely and limits any single side to 12 feet. More than 20 states set no statewide figure at all and hand the decision to your city or county. Here's how it breaks down.
What we found
The map
New York City uses its own building code separate from New York State. Tiles are positioned approximately; see the table below for each state's details.
The biggest shed you can build without a permit, state by state
The table shows the edition of the IRC each state currently references, whether the rule is set at the state or local level, and what that means for a shed permit. Where a state defers to local jurisdictions, your city or county sets the threshold — commonly between 100 and 200 square feet.
| State | IRC edition | Code authority | Shed building permit |
|---|---|---|---|
| Alabama | 2021 | Local enforcement | Set by local jurisdiction |
| Alaska | 2018 | Local (Anchorage statewide) | Set by local jurisdiction |
| Arizona | 2018 | Local | Set by local jurisdiction |
| Arkansas | 2021 | Local (state buildings only) | Set by local jurisdiction |
| California | 2024 | Statewide (CA Codes) | Not required under 120 sq ft † |
| Colorado | 2021 | Local (home rule) | Set by local jurisdiction |
| Connecticut | 2021 | Statewide | Not required under 200 sq ft † |
| Delaware | 2018 | Local | Set by local jurisdiction |
| District of Columbia | 2015 | District-wide | Not required under 50 sq ft † (one shed per lot) |
| Florida | 2021 | Statewide + local | Varies — verify locally (county-set; hurricane zones require permits) |
| Georgia | 2024 | Statewide | Not required under 200 sq ft † (several metro-Atlanta counties stricter) |
| Hawaii | 2018 | Local (by county) | Set by local jurisdiction |
| Idaho | 2018 | Statewide | Not required under 200 sq ft † |
| Illinois | Local | Local | Set by local jurisdiction |
| Indiana | 2018 | Local (state code omits sheds) | Set by local jurisdiction |
| Iowa | 2024 | Statewide | Not required under 200 sq ft † (some cities 120) |
| Kansas | 2018 | Local | Set by local jurisdiction |
| Kentucky | 2015 | Statewide (local may vary) | Not required under 200 sq ft † |
| Louisiana | 2021 | Statewide | Not required under 200 sq ft † (up to 500 in low-wind parishes) |
| Maine | 2021 | Cities over 4,000 | Varies (large towns only) |
| Maryland | 2021 | Statewide + local | Not required under 200 sq ft † (Montgomery & Prince George's require all) |
| Massachusetts | 2021 | Statewide + local | Not required under 200 sq ft † |
| Michigan | 2015 | Statewide | Not required under 200 sq ft † |
| Minnesota | 2018 | Statewide | Not required under 200 sq ft † |
| Mississippi | 2012–2018 | Local | Set by local jurisdiction |
| Missouri | 2018 | Local | Set by local jurisdiction |
| Montana | 2021 | Local option | Set by local jurisdiction |
| Nebraska | 2018 | Local (residential) | Set by local jurisdiction |
| Nevada | 2024 | Statewide + local | Not required under 200 sq ft † (no statewide code; Clark/Washoe standard) |
| New Hampshire | 2021 | Statewide | Not required under 200 sq ft † |
| New Jersey | 2021 | Statewide | Not required under 200 sq ft † |
| New Mexico | 2021 | Statewide | Not required under 120 sq ft † |
| New York | 2024 | Statewide (exc. NYC) | Not required under 144 sq ft † (adopted town-by-town; NYC stricter) |
| North Carolina | 2015 | Statewide | No permit if every side is 12 ft or less † |
| North Dakota | 2021 | Statewide | Not required under 120 sq ft † |
| Ohio | 2018 | Statewide | Not required under 200 sq ft † |
| Oklahoma | 2018 | Statewide | Not required under 200 sq ft † (state base model; some cities vary) |
| Oregon | 2021 | Statewide | Not required under 200 sq ft † |
| Pennsylvania | 2021 | Statewide (opt-in) | Not required under 1,000 sq ft † (most localities amend down) |
| Rhode Island | 2021 | Statewide | Not required under 200 sq ft † |
| South Carolina | 2021 | Statewide | Not required under 200 sq ft † |
| South Dakota | 2021 | Local option | Set by local jurisdiction |
| Tennessee | 2021 | Local / opt-out areas | Set by local jurisdiction |
| Texas | 2021 | Local (no statewide code) | Set by local jurisdiction |
| Utah | 2021 | Statewide (local may vary) | Not required under 200 sq ft † |
| Vermont | — | No statewide IRC for homes | Different framework — verify locally |
| Virginia | 2021 | Statewide | Not required under 256 sq ft † |
| Washington | 2021 | Statewide | Not required under 120 sq ft † (state floor; many localities 200) |
| West Virginia | 2018 | Local option | Set by local jurisdiction |
| Wisconsin | 2015 | Local (sheds outside UDC) | Set by local jurisdiction |
| Wyoming | Local | Local | Set by local jurisdiction |
† The exemption applies only to a detached, one-story shed used for storage. It does not waive zoning rules, and several conditions can require a permit anyway — see below.
The catch: a permit-free shed still has rules
Even where no building permit is required, "no permit" does not mean "no rules." Homeowners are caught off guard by these every year:
What can still require a permit — or trip you up
- Electrical or plumbing. The moment you run power or water to the shed, a permit is almost always required, regardless of size.
- Zoning & setbacks. Distance from property lines, easements, and lot-coverage limits apply to every structure, permit or not.
- A stricter local limit. Many cities lower the threshold to 120 or even 100 square feet, below the national 200.
- Foundation type. A permanent slab foundation can change the classification of the structure.
- HOA approval. A separate process entirely from your city — and one the building code says nothing about.
Check your state instantly
Use the free tool below to see whether your state requires a building permit for a shed. You're welcome to embed it on your own site.
Embed this free tool
Copy the code below to add the checker to your own site (attribution required):
How to check your local rule
The map shows your state's baseline, but the only way to be certain is your local building department. Find your state below, pick your county, and you'll get the local building department's contact details to confirm before you build.
Find your county's building department
We track permit contacts and portals for 3,000+ U.S. counties across all 50 states.
Find your state's directory →How we did this & sources
The starting point is the building-permit exemption in Section R105.2(1) of the International Residential Code (IRC), which exempts one-story detached accessory structures (sheds) of 200 square feet or less. But that 200 sq ft figure is only a model baseline: many states amend it when they adopt the code. So rather than assume the IRC number everywhere, we checked each state's adopted and amended residential code — or the administering agency's published permit guidance — against primary state sources, and recorded the figure actually in force. That is why the thresholds in the table range from 50 sq ft (District of Columbia) to 1,000 sq ft (Pennsylvania), and why North Carolina appears with a 12-foot dimension rule rather than an area limit.
States are classified as statewide when a state-level residential code sets a specific shed exemption (the size is shown per state, since it is not always 200), local when there is no mandatory statewide figure and the decision rests with the city or county, and a special case for Vermont — which does not adopt the IRC statewide for one- and two-family homes; residential construction there runs through the state's own Fire and Building Safety Code — and for Florida, where the statewide code is applied unevenly by county and the Miami-Dade/Broward hurricane zone requires permitted, engineered construction regardless of size. A handful of statewide figures rest on a state agency's published guidance rather than the raw code text, and are noted as such where relevant. Code adoption is dynamic and local jurisdictions frequently amend the baseline further; this study is general guidance, not legal advice. Always confirm with your local building department before you build.
Sources: International Residential Code §R105.2 (International Code Council, iccsafe.org) for the model baseline; individual state residential codes, administrative codes, and building-agency permit guidance for each state's in-force threshold.
Use this data
Free to cite & republish
Journalists and writers are welcome to use these findings, the table, and the map, with a link back to the source. Suggested attribution:
Source: StateDataIndex — "How Big a Shed Can You Build Without a Permit? All 50 States (2026)" — https://statedataindex.com/studies/shed-permit-by-state