Do You Need a Permit to Build a Shed? Size Rules by State

What size shed can you build without a permit?

Two thresholds cover most of the country, and knowing which one applies to you answers the question in seconds.

The modern default is 200 square feet. That’s the exemption written into the International Residential Code, the model code most states build on, and it means a 10×20 or 12×16 shed often needs no building permit at all. The older, stricter line is 120 square feet, still used by California and by plenty of individual cities that never moved up. Under a 120 rule, a 10×12 is your ceiling.

If you’re searching “what size shed can I build without a permit,” the honest answer is: find your state in the table below, then confirm with your city, because local governments are allowed to be stricter than the state code and often are.

Height matters too. Permit-free usually also means one story and under a height cap, typically 10 to 15 feet depending on the jurisdiction. A lofted barn with a tall gambrel roof can trip the height rule while sitting comfortably under the square-footage one.

How the square footage gets measured is worth one phone-call question of its own. Most codes measure floor area, but jurisdictions differ on whether roof overhangs, attached lean-tos, or porches count toward the number. If your shed is anywhere near the line, ask how they measure before you order.

One more wrinkle: a few states don’t set a statewide residential code at all, leaving the whole question to cities and counties. Texas is the famous example. In those states, the table says so, and your county is the only answer that counts.

When you need a permit no matter the size

Square footage is only the first gate. Four things put you in permit territory at any size:

Electricity. Running power to a shed needs an electrical permit almost everywhere, even when the structure itself is exempt. This applies to every workshop and every backyard office shed: if it has outlets, plan on a permit and a licensed electrician.

Plumbing. Water or sewer lines reclassify the project in most jurisdictions. Expect full permits and inspections.

Habitable use. Sleeping space or guest quarters means it’s not a shed anymore in the code’s eyes. Habitable structures carry residential requirements like insulation and egress windows, and often tiny-home or ADU rules on top.

Your HOA. Not a government, but functionally a second permit office. HOA approval requirements are separate from county rules and frequently stricter about size, placement, and appearance. Get it in writing before anything is delivered.

There’s also a distinction worth knowing because it trips people up at the counter: a building permit and a zoning permit are two different approvals. The building permit covers how the structure is built; zoning covers whether it can sit where you want it. Philadelphia, for example, requires both for most sheds. California flips it the other way, where sheds under 120 square feet can skip the building permit but may still need planning approval. When you call your building department, ask about both.

And setbacks apply even to permit-free sheds. Rules commonly want accessory structures 5 to 10 feet off property lines, though some cities allow as little as 2 or 3 feet for small sheds on rear lines. Easements are their own no-build zones. A permit-free shed built on the property line can still earn you a forced move.

How much does a shed permit cost?

Typically $50 to $200 for a standard storage shed, based on published fee schedules and what builders in our network see across jurisdictions. The variables that move it: your shed’s size and value (some counties price permits as a percentage of project cost), whether plan review is required, and whether electrical or plumbing permits stack on top.

Those add-on permits are their own line items. An electrical permit for a wired shed usually runs separately from the building permit, and a plan-review fee can apply on larger buildings. Even fully stacked, permits rarely pass a few hundred dollars.

Compare that to the building itself and the permit is a rounding error. It’s roughly the cost of one month’s payment on a rent-to-own shed, and the money you might save by skipping it is a bad trade, as the next section explains.

Permit rules by common shed size

The quick math for the sizes people actually buy:

• 8×10 (80 sq ft): Under every common threshold, including 120 sq ft states. The safest permit-free size on the market.
• 10×10 (100 sq ft): Under both common thresholds. Permit-free almost everywhere without utilities.
• 10×12 (120 sq ft): The edge case. Fine in 200 sq ft states; exactly at the line under a 120 rule, where “under 120” and “120 or less” are different sheds. Ask your city which way they read it.
• 12×12 (144 sq ft): Permit-free in 200 sq ft states, needs a permit under a 120 rule, and sits exactly at New York’s line.
• 10×16 (160 sq ft): Comfortable in 200 sq ft states; permit territory under 120 and 144 rules.
• 12×16 (192 sq ft): Just under the 200 sq ft default, and the biggest commonly sold shed that usually avoids a permit.
• 12×20 and up (240+ sq ft): Over both common thresholds, so plan on a permit almost everywhere. Virginia’s 256 sq ft exemption is the notable exception.

Browse shed styles and sizes with your threshold in mind. Sometimes the difference between paperwork and no paperwork is one size down, and sometimes the bigger shed is worth the errand.