Do You Need a Building Permit to Build a Shed?

Two model codes give two different numbers, and that is the source of most conflicting advice online.

Which one applies depends on how your jurisdiction regulates detached accessory structures on a house lot. Some use the IRC figure, some use the IBC figure, and some split the difference. Sacramento County, California publishes a sheet that exempts detached structures under 120 sq ft and under 9 ft tall, and a second band of 120 to 200 sq ft that is exempt only if it is one story and under 12 ft tall. The City of Sacramento is stricter: its handout requires a building permit for a detached non-living structure of 120 sq ft or more.

Two neighbors a few miles apart can get different answers. Treat any number you read in an article, including this one, as a starting point.

The size limit is rarely the only test. Local handouts that restate the model code add conditions like these:

• Use. Sacramento County's older sheet says the structure cannot be used for human habitation or commercial use.
• Height. The same sheet caps height at 9 ft. Ventura County's amendment uses 15 ft.
• Enclosure. Sacramento County says the structure cannot be enclosed on more than three sides.
• Count and shape. One municipal code found in search limits each lot to two exempt structures, each at 200 sq ft, with 24-inch eaves and a 10 ft wall height.
• Mechanical and plumbing. One county document found in search says the structure must not contain plumbing or mechanical equipment.

The IBC itself says exemptions do not grant authorization for work that violates the code. An exempt shed still has to be safe and still has to follow the rest of your local rules.

Electricity, plumbing and gas

Running power to a shed is the most common reason a small one ends up permitted. Sacramento County's sheet says electrical or plumbing added to an exempt structure needs a miscellaneous permit. Phoenix says that when utilities are provided to a detached accessory structure that is exempt from permit, a permit is required for the utility installation. The City of Sacramento requires a permit for any associated gas, mechanical or electrical work.

If you want a light and an outlet, plan for an electrical permit even if the shed itself is exempt.

Zoning and setbacks

A building permit exemption is not a zoning exemption. Search results from several jurisdictions make the same point: setbacks, lot coverage and height limits apply whether or not you pull a building permit. Kitsap County's amendment, for one, says the exempt structure must meet all zoning and building setbacks. Some places even keep a separate location or zoning permit. Wichita, for example, still requires a location permit for structures that are exempt from building permits.

Sacramento County's planning handout shows how setback rules can bend for small sheds: structures of 120 sq ft or less and 9 ft tall may sit on the property line there. Elsewhere that would be a violation. Check your zoning code before you pick a spot.

Foundations, lofts and sizes over the limit

If the shed has a loft, a permanent foundation or a footprint over the threshold, assume a permit. One local code found in search excludes structures with loft storage from the exemption.

1. Find the adopted code. Search your city or county name with "adopted building code" or "building code amendments." Note the edition and any local change to Section 105.2 or R105.2.
2. Read the local exemption handout. Many building departments publish a one-page list of work exempt from permit. It will give the size, height and use conditions in plain terms.
3. Check zoning separately. Look up your zone's accessory-structure rules: setbacks, height, lot coverage and number of structures.
4. Check utilities. Decide now whether the shed gets power, water or gas. Each one adds a permit step.
5. Check private rules. HOAs and recorded covenants can limit sheds regardless of what the city requires. Search results mention HOA rules as a common extra constraint.
6. Call or email the building department. Ask the question with your size, height and utilities. Keep the reply.

Jurisdiction rules for larger projects are collected on pages like Los Angeles building permits. For fee and process questions on shed-size and larger work, see how much a building permit costs and how long a building permit is good for.

Skipping a required permit can be expensive. Search results from local authorities say they can order the structure moved or taken down completely. Building the shed first and asking later puts you in the worst position: you may need to open walls for inspection or remove the work. If you are unsure, ask first. It costs a phone call.

If you do need a permit, the application usually wants a site plan showing the shed's location and distances to property lines, plus the shed's dimensions and height. If you manage several permits at once, see how plan check correction tracking works.