Do I need a permit for a shed?

Most places in the United States base their building rules on the International Code Council’s model codes, then adopt them with local changes.

• The International Residential Code, used for houses and their accessory buildings, exempts one-story detached accessory structures other than storm shelters, as long as the floor area doesn’t exceed 200 square feet. Editions before 2021 limited that to tool and storage sheds, playhouses and similar uses.
• The International Building Code, used for other buildings, exempts tool and storage sheds, playhouses and similar uses up to 120 square feet.

Those are starting points, not the rule where you live. Many jurisdictions lower or raise the limit, cap the height, measure the footprint instead of the floor area, or count a roof overhang. Some don’t use the model codes at all.

Also think about how you’ll use it. A shed that becomes a home office, a guest room or a place to sleep may be treated as a different kind of building, with different rules.

And an exemption from the permit isn’t an exemption from the code. An exempt shed is still expected to be built safely and to meet the rules that apply to it.

Most shed questions come down to one number: floor area. Here’s how common sizes compare with the two model-code limits. Treat it as a starting point for your call to the building department, not an answer for your lot.

A few things change the answer even when the area fits:

• How area is measured. Some places use the outside footprint, and some count a roof overhang or a loft.
• Dimension or height limits. Some codes look at the longest side or the height instead of the area. North Carolina’s residential code, for example, applies to accessory buildings with any dimension greater than 12 feet, so a 12 × 16 shed there falls under it.
• Lower local limits. Many cities and counties use 100, 120 or 150 square feet instead of 200.

Planning something bigger, like a garage or pole barn? See do you need a permit to build a garage.

Skipping the building permit doesn’t mean skipping every rule. Check these before you build:

• Zoning setbacks. Most zoning codes set minimum distances from accessory buildings to the side and rear property lines, and many don’t allow them in the front yard.
• Height limits. Accessory buildings often have their own maximum height.
• Lot coverage. The shed may count toward a limit on how much of your lot can be covered by buildings.
• Easements. You generally can’t build in a utility or drainage easement.
• HOA rules and covenants. Your homeowners association may require approval, or limit size, style or location.
• Floodplain rules. Sheds in a mapped flood zone may need a floodplain permit or special construction.
• Electrical and plumbing. Running power or water to the shed usually needs its own permit and inspection, even when the shed itself doesn’t.
• Foundations. In some places, a permanent foundation or slab changes how the shed is treated.

1. Find your jurisdiction. If you live inside city limits, it’s usually the city. In an unincorporated area, it’s usually the county.
2. Check the building department’s website. Search it for “accessory structure” or “shed.” Many publish a one-page handout with the size limit and what they need.
3. Check the zoning code. Look up your zoning district, then the rules for accessory buildings: setbacks, height and coverage.
4. Call with specifics. Give them the shed’s size, height, location on the lot, foundation, and whether it will have power or water. The details change the answer.
5. Check your HOA, if you have one, before you order materials.
6. Keep a record. Note who you talked to, the date and what they said, or ask for the answer by email.

Before you dig for footings or a trench, call 811 so buried utilities get marked.

If your shed does need a permit, the building department will usually ask for a short set of drawings:

• Site plan. The shed’s location with distances to property lines and other buildings, plus easements. See how to draw a site plan.
• Floor plan. Overall dimensions and the door and window locations.
• Elevations. Each side, with the overall height.
• Wall section or framing details. The foundation or anchoring, floor framing, wall studs, roof framing and roofing.
• Electrical plan. If you’re running power.

Some departments accept a simple, clearly dimensioned hand sketch for a small shed. Others want drawings to scale. Ask which they need.

The same rules apply to a shed you buy as one you build. Some suppliers provide drawings or specifications you can include with a permit application. You’ll still need your own site plan, because only you know where it’s going. In high-wind areas, ask how the shed must be anchored.

AI CAD PRO is free shed plan software for Windows. Describe your shed, and the AI assistant helps you draw the site plan, floor plan, elevations and a section as editable CAD objects. Attach your survey or plat for the site plan, preview each sheet exactly as it will print, and export a PDF set.

Ready to test a layout? Work through the 12 × 16 shed drawing exercise, including a dimensioned opening and a revision check, then adapt it to your own measurements.

It won’t tell you whether your shed needs a permit. Only your local building department can do that.

Plan a shed you can actually use. Start with how you will use the shed. A list of equipment and access needs produces a more useful drawing than 'make me a shed plan.'

Measure the space available, the widest item you will move through the door and any fixed equipment. Decide which sizes are confirmed and which are preferences.

Copy a prompt, replace the bracketed examples with your details, and paste it into Astra’s chat in your project. Send one step at a time and check the result before continuing.

Give Astra a footprint, an entry and the activities that need space.

Draw a [12 by 16 foot] shed floor plan for [garden tools and a riding mower]. Put [double doors centered on the 12-foot south wall] and [one window on the east wall]. Reserve a [2-foot-deep workbench along the north wall]. Show overall dimensions and opening widths. Ask me for the mower and door measurements if needed; do not guess them.

What to check: Confirm that the mower can enter, turn and park without blocking the workbench.

Explain the problem and preserve the dimensions you have already chosen.

Keep the [12 by 16 foot] footprint and entry doors. Move the storage so I can reach the workbench without moving the mower. Suggest two arrangements, explain their tradeoffs, and wait for me to choose before updating the drawing.

What to check: Check the walking route and the equipment clearances using your actual measurements.

Once the layout works, identify the information needed for additional views.

The floor layout is agreed. I want elevations and a section for a [gable roof] shed. First list the heights, roof pitch, foundation and framing information you still need. Use only the specifications I provide, and identify details that need confirmation rather than choosing structural sizes for me.

What to check: Check that openings and heights agree across the floor plan and elevations.

For the permit question, give your building department the size, height, location, foundation and utility plans. Record their answer and feed the resulting drawing requirements back to Astra.