Permits, honestly
Why no tool can just tell you "yes" or "no"
And why the useful answer is knowing which questions to ask.
There is no national shed permit rule
Permit requirements are set locally — there are thousands of permitting jurisdictions in the US, and they genuinely disagree with each other. Any website that claims to know whether your shed needs a permit is guessing, and a confident wrong answer is worse than no answer.
So this tool does something more honest and more useful: it works through the factors that commonly trigger a permit or a separate approval, tells you which ones apply to your plan, and hands you the exact questions to confirm with the one authority that can actually answer them — your local building department.
The factors that decide it
- Floor area. Two thresholds recur: the 120 sq ft limit many local codes still use, and the 200 sq ft exemption in the current IRC (R105.2). Work out your footprint first with the Size Calculator.
- Height. Many jurisdictions cap accessory-building height and require review above it.
- Foundation. A permanent slab or footings makes the shed a fixed structure, which is scrutinised more than a portable, skid-mounted one.
- Utilities. Running electrical or plumbing almost always needs its own permit and inspection, whatever the shed's size.
- Placement. Zoning setbacks govern how close you can build to a property line — a separate approval from a building permit.
- Use. A habitable space — office, studio, sleeping — falls under far stricter rules. Our studio shed guide covers that step up.
The one call worth making
The single best thing you can do is phone your local building department before you buy materials. They'll tell you exactly what applies to your address in a few minutes. This checker exists to make that call productive — you arrive with a specific, personalised list rather than a vague "do I need a permit?"
It also matters because getting it wrong is expensive. Building without a required permit can mean fines, a stop-work order, a costly retroactive application, or being told to modify or remove the shed — and it can complicate a future sale.
What this tool is not
It is not legal advice, and it is not a permit decision. The thresholds it uses are national reference points; your local rules override them completely. Treat the result as preparation for a conversation, not a substitute for one — and read our disclaimer before relying on it.