Do You Need a Permit for a Shed or Deck?

Why some projects need a permit and others don't

A building permit exists to make sure construction is safe and code-compliant. For very small, low-risk structures, many jurisdictions waive the permit requirement because the safety stakes are low. As a structure gets bigger, taller, or more permanent — and therefore more capable of failing in a way that hurts someone or a neighbor's property — the permit requirement kicks in.

That is why thresholds exist. A tiny tool shed or a ground-level platform poses little risk; a large outbuilding or an elevated deck that people stand on does. The exact lines are drawn locally, but the underlying logic — size, height, and permanence drive the requirement — is consistent almost everywhere.

Typical thresholds for sheds

For sheds, the most common trigger is floor area. Many jurisdictions exempt small accessory structures under a certain size — figures like 120 or 200 square feet are common cutoffs — from needing a building permit, while anything larger requires one. Height can also matter, and some places exempt only one-story structures below a set height.

Foundation type can matter as well — a shed set on a permanent concrete foundation is more likely to need a permit than one resting on skids or a gravel pad, because a permanent foundation makes the structure, well, permanent. But a size exemption from the building permit does not mean "anything goes." Even an exempt shed usually still has to obey zoning rules: setbacks from property lines, lot-coverage limits, and placement restrictions. And if you run electrical or plumbing to the shed, that work typically needs its own permit regardless of the structure's size. Always confirm both the building and zoning rules locally.

Typical thresholds for decks

Decks are commonly triggered by height above grade and size. A frequent pattern is that low, ground-level decks below a certain height — often around 30 inches above grade — may be exempt, while anything higher, or attached to the house, requires a permit. Attachment matters because a deck connected to the house (via a ledger board) involves structural and safety considerations that jurisdictions want inspected.

Guardrails, stairs, footings, and how the deck ties into the house all factor into both the requirement and the inspection. A raised deck that fails can cause serious injury, which is why height is such a common trigger. Roofed or covered decks, and decks that double as a carport or form part of a larger structure, are also more likely to require a permit regardless of height. As with sheds, the specific height and size cutoffs vary by jurisdiction, so check yours before you build.

Beyond size: other factors that matter

Size and height are the headline triggers, but several other factors can require a permit or change the rules. Location matters: properties in flood zones, coastal areas, historic districts, or hillside areas often face stricter requirements regardless of project size. Homeowners-association rules can add another layer of approval entirely separate from the city's permit.

Utilities are a big one: adding electrical, plumbing, or gas to a shed or deck almost always requires a permit for that work even when the structure itself is exempt. And zoning rules — setbacks, easements, and lot coverage — apply to exempt structures too. The building-permit question is only one part of "can I legally build this here."

How to check your jurisdiction

Because the thresholds genuinely vary, the only reliable answer is your local building department. Most jurisdictions publish their permit-exemption rules online or will tell you over the phone or counter exactly what triggers a permit for a shed or deck. A five-minute check up front is far cheaper than a stop-work order or having to remove a non-compliant structure later.

It also helps to see what is being permitted around you. You can look up recent permit activity with our permit lookup tool, drawn from official open-data portals across 65 cities in 37 US states. If you are a contractor or supplier who wants to track deck, shed, and other residential permit activity across your markets, request access to Igni. (General information only — verify requirements with your jurisdiction.)

Frequently asked questions