Before you build a shed, backyard office, or cabin, one question can save you a lot of trouble: do you need a permit? The rules vary by location, but the general principles are consistent. Here is how to know whether your build needs a permit – and how to check.
The general rule
Most areas let you build a small, non-habitable storage shed without a permit if it is under a certain size – often somewhere around 100 to 200 square feet, though the exact threshold varies widely. Once a structure gets larger, or becomes habitable (a room people use), permit requirements usually kick in.
What tends to trigger a permit
- Size over the local threshold (commonly around 100-200 sq ft, but confirm locally).
- Permanent electrical wiring – running power almost always needs an electrical permit.
- Plumbing – a bathroom or sink adds plumbing permits.
- Habitable space – a backyard office, studio, or cabin used as a room often must meet building codes (insulation, egress, ceiling height).
- Attaching to your house or building on a permanent foundation.
Beyond the permit: setbacks and rules
Even a permit-free shed usually has to follow other rules:
- Setbacks – minimum distance from property lines and other buildings.
- Height limits for accessory structures.
- HOA rules, which can be stricter than local code.
- Zoning – whether you can legally use a backyard building as an office or dwelling.
How to check (in 15 minutes)
- Search your city or county name plus “accessory structure permit” or “shed permit.”
- Note the size threshold and setback distances.
- Call or email your local building department with your planned size and use – they answer this all the time.
- Check your HOA covenants if you have one.
Doing this before you build is far cheaper than being told to move or tear down a finished structure.
Ready to build?
Confirm your local rules, keep a storage shed under the threshold if you want to skip the permit, and plan for code if you are building a habitable office or cabin. See our roundup of the best backyard office and cabin plans and our best shed plans for 2026 to find the right size for your project.