Do I need
a permit
for that?
Most people find out the expensive way — at inspection, at resale, or when a neighbour calls it in.
Where is the work?
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.