Add a shed or small outbuilding

One-story detached sheds are typically exempt up to 200 square feet under the residential code — but the number people quote is 120, and both are right depending on which code your jurisdiction adopted.

Permit rules are set locally, so the ZIP decides which state code applies and which office you would be dealing with. We use it to look up the jurisdiction and nothing else.

Why nobody can just tell you

Permitting in the United States is run by thousands of separate authorities, and each one can amend the code it adopts. Any site giving you a confident yes or no for every address in the country is guessing, and you cannot tell which answers are the guesses.

22,662counties and incorporated places that could issue your permit

41%of Americans live where the state code does not settle it

30%of ZIP codes straddle a county line, so even the office is ambiguous

So this does not pretend. Each answer is the typical rule, where it comes from, and the thresholds that would flip it — plus a route to the office that actually decides. How this works.