Do I Need a Permit for a Shed?

Small storage sheds are one of the few structures the model building code lets most homeowners build without a building permit. The catch is that “small” has different meanings in different places, and the building permit is only one of the approvals that may apply. Zoning rules on placement, height, and lot coverage apply even to permit-exempt sheds, and any electrical or plumbing work brings its own permits.

This guide covers the typical rules under the model codes and the local variations that most often trip people up. To confirm what applies at your address, find your local building department and ask before you buy or build.

What the model code exempts

Section R105.2 of the 2021 International Residential Code (IRC), Building item 1, exempts “one-story detached accessory structures, provided that the floor area does not exceed 200 square feet.” Storm shelters are excluded from the exemption.

Each part of that sentence matters:

• One-story. A shed with a loft that adds a second floor level may not qualify.
• Detached. A storage room attached to the house is an addition, not a shed.
• Accessory structure. The IRC defines this as a structure accessory and incidental to the dwelling on the same lot. The 2021 model text doesn’t spell out a storage use, but many local versions do: Phoenix’s code still says “tool and storage sheds, playhouses and similar uses,” and Seattle limits its exemption to storage, growing plants, and similar generally unoccupied uses. A shed used as an office, studio, or guest room usually falls outside those local exemptions.
• 200 square feet of floor area. The model code measures floor area. Some cities measure the roof instead: Seattle and Denver both count projected roof area, so overhangs can push a shed over the limit.

The International Building Code, which governs commercial construction, uses a lower limit of 120 square feet for the same kind of structure (IBC 105.2). Some cities apply a lower limit to homes as well, and some require a permit for every shed regardless of size.

The code also states that an exemption from a permit does not authorize work that violates the code or other laws. An exempt shed still has to meet zoning and be built safely.

When you usually need a permit

You will typically need a building permit, and possibly other permits, when:

• The shed is larger than the local exemption (200 square feet under the model IRC, 120 square feet of roof area in Seattle).
• The structure is taller than one story or has a usable second level.
• You plan to run electricity, plumbing, or gas to it. These usually require trade permits even when the shed itself is exempt.
• The shed will be used as habitable space, such as an office, studio, gym, or bedroom.
• It’s attached to the house, garage, or another structure.
• The site is in a mapped flood hazard area, where accessory structures have specific requirements.
• The shed sits on a permanent foundation that the local code treats differently from skids or blocks.

Work that is often exempt

Depending on local rules, these frequently need no building permit:

• Storage sheds and playhouses under the local size threshold.
• Prefabricated plastic or metal storage units under the threshold.
• Swings and other playground equipment, which the model IRC lists separately as exempt.
• Re-roofing or repainting an existing small shed (some cities still require a permit for re-roofing).

Exempt from a building permit does not mean exempt from zoning. Many cities require a zoning permit or site plan review for any accessory structure.

Zoning and HOA rules are separate

Zoning is where most shed questions are actually decided. Common local rules include:

• Setbacks. Minimum distances from side and rear property lines, sometimes increasing with shed height.
• Placement. Many codes prohibit accessory structures in front yards or require them to sit behind the house.
• Height limits for accessory structures, often lower than for the house.
• Lot coverage. Sheds generally count toward the maximum share of the lot that can be covered by structures.
• Number of accessory structures allowed on one lot.
• Easements. Utility and drainage easements commonly prohibit permanent structures. A utility can require removal of anything built over its lines.
• Floodplain rules. In a mapped flood hazard area, accessory structures may need flood openings, anchoring, and flood-resistant materials, and local floodplain managers often require a permit even for small sheds.
• Historic districts may review visible sheds.

HOA covenants frequently control shed size, location, materials, and colors, and many require approval before you place one. A shed that complies with city rules can still violate HOA rules, and the reverse is also true.

How the rules differ by city

Shed exemptions vary in size, height, and how size is measured. Examples from official city and county sources:

• Seattle exempts a shed only if its roof footprint is 120 square feet or less, it is one story, it sits on a simple slab, pier blocks, or soil, it is detached, it is not in or near an environmentally critical area, and it is used only for storage, growing plants, or similar unoccupied uses. Zoning separately limits shed height to 12 feet.
• Denver exempts one-story, detached, non-conditioned sheds of no more than 200 square feet of projected roof area, an 8-foot top plate height, and 14 feet of total height. Up to two lights and two receptacles are allowed under an electrical permit. Sheds in Former Chapter 59 zone districts need a zoning permit regardless.
• Austin uses 200 square feet but adds limits the IRC doesn’t: no more than 15 feet tall, no plumbing, not creating a dwelling, and not in a flood hazard area.
• Fairfax County, Virginia doesn’t require a permit for detached storage sheds up to 256 square feet and one story, though zoning setbacks and site approvals may still apply.
• Phoenix exempts storage sheds, playhouses, ramadas, and gazebos up to 200 square feet of aggregate floor area, per its published work-exempt guideline (revised July 2014). The guideline adds that if utilities are run to an exempt structure, the utility work needs a permit.

Foundations, anchoring, and utilities

Even for exempt sheds, a few practical points save trouble:

• Anchoring. In high-wind regions, sheds may need to be anchored to resist uplift. Ask whether your area has specific tie-down requirements.
• Foundation type. Sheds on skids or concrete blocks are generally treated differently from those on a poured slab or frost-protected footings. A slab may trigger a permit or inspection even for a small shed.
• Digging. Contact 811 before digging for footings, piers, or a trench for wiring. The service is free and is required in many states before excavation.
• Electrical. Underground wiring to a shed has minimum burial depths and usually needs GFCI protection for receptacles. An extension cord run from the house is not a permanent substitute.

What the inspection covers

For a permitted shed, inspections often include:

1. Footing or slab inspection before concrete is placed, if there is a permanent foundation.
2. Framing inspection, checking wall and roof framing, headers, and anchorage.
3. Electrical inspections, including the trench before backfill and rough wiring, if power is being added.
4. Final inspection of the completed structure and its location on the lot.

Small permitted sheds sometimes need only a final inspection. Ask which inspections your department requires.

What to have ready when you apply

A typical shed application asks for:

• Site plan showing property lines, the house, the shed’s location, distances to property lines and other structures, and any easements.
• Shed dimensions, floor area, and height, often with a simple floor plan and elevation.
• Foundation and anchorage details.
• Manufacturer’s drawings or specifications for a prefab or kit shed. Some manufacturers can supply engineered drawings for wind and snow loads.
• Electrical plan if you’re adding power.
• HOA approval if your city requests it.

Before you buy or build, run through this checklist:

• Measure both the floor area and the roof footprint, including overhangs.
• Check the height limit for accessory structures, and whether your city measures to the top plate or the peak.
• Confirm setbacks, lot coverage, and any easements on your site plan.
• Check whether your lot is in a flood hazard area.
• Decide now whether you’ll want power, water, or heat, since each brings its own permit.
• Get HOA approval if you have an HOA.
• Call 811 before digging for piers, footings, or a wiring trench.

Hiring a contractor vs doing it yourself

Most homeowners can build their own shed and pull their own permit if one is required. See our guide to owner-builder permits for common conditions. Electrical work is different: some jurisdictions let homeowners wire their own property with a permit, while others require a licensed electrician. Our electrical permit guide covers that in more detail.

If you buy a prefab shed with delivery, ask whether the company handles permits. Many do not, and the responsibility falls on the property owner.

Questions to ask your building department

• What is the maximum size for a shed without a building permit here?
• Is a zoning permit or site plan required even for exempt sheds?
• What are the setbacks and height limits for accessory structures?
• Do sheds need to be anchored, and to what standard?
• Does running power to a shed require a licensed electrician?
• Is my lot in a flood hazard area?

If you’re thinking about a shed you or others will live in, the rules change significantly. See our guide to accessory dwelling unit permits.