Last checked: October 2026. Answer a few questions about your project and this free checker tells you whether it likely needs a building permit, why, and where the rule comes from. It uses the exemptions in the International Residential Code (IRC), which most U.S. cities adopt, plus the published limits for cities we have researched: Austin, Chicago, Denver, Houston, Los Angeles, Phoenix, Portland and Seattle.
This is a starting point, not a permit decision. Your local building department (your AHJ, or authority having jurisdiction) has the final word, and zoning, HOA and historic-district rules can apply even when a building permit does not. See our disclaimer.
Highest point of the walking surface.
Add up all sheds on the lot for Phoenix.
How the checker decides
Most U.S. building codes start from the same list of exempt work in IRC Section R105.2. Under that model list, these are usually exempt from a building permit:
- One-story detached accessory structures up to 200 square feet.
- Fences up to 7 feet high.
- Retaining walls up to 4 feet, measured from the bottom of the footing, unless they support a surcharge.
- Decks up to 200 square feet and 30 inches above grade that are not attached to the house and do not serve a required exit door.
- Prefabricated pools less than 24 inches deep.
- Painting, papering, tiling, carpeting, cabinets, countertops and similar finish work.
Cities can change these numbers, and many do. Chicago exempts sheds only up to 70 square feet, Seattle and Houston use about 120 square feet, and Phoenix exempts fences only up to 3 feet. When you pick one of our researched cities, the checker uses that city's published limits and links to our full guide. When we have not confirmed a city's number for a specific project, it falls back to the model code and says so.
Next steps
- Confirm the result on your building department's website. Use our Building Permit Lookup by State to find it.
- Check zoning setbacks, height limits and HOA rules, even if no building permit is needed.
- Call before you build if the checker says "check locally". Our 10-minute AHJ permit checklist lists the questions to ask.
FAQ
If the checker says no permit, can I skip calling the city?
We recommend a quick call or email anyway. Local amendments, historic districts, flood zones and utility easements can all change the answer, and a written "no permit needed" reply protects you later.
Does "no building permit" mean no rules apply?
No. Exempt work still has to meet the building code and zoning. Setbacks, lot coverage, height limits and HOA covenants still apply.
Why does electrical or plumbing work almost always need a permit?
Trade work carries fire, shock and gas risks, so most jurisdictions require permits for anything beyond minor repairs, and many require a licensed contractor. See our electrical permit guide.
Can I link to this checker?
Yes. Contractors, home inspectors, real estate agents and HOAs are welcome to link to it. If a city rule has changed, tell us through our contact page.
How to use the checker
- Pick the location. If your city is not listed, choose "Other U.S. city or county". The checker then uses the model-code list, which your city may have changed.
- Pick the closest project type. If your job mixes several things, such as a deck with a new outdoor outlet, run the checker once for each part. A building permit exemption for the deck does not cover the electrical work.
- Measure before you answer. Use the highest point of a deck above the ground, the full floor area of a shed, and the height of a retaining wall from the bottom of the footing. Small differences matter right at the limits.
- Tick every box that applies. Attachment to the house, a roof, utilities, a surcharge, or a pool barrier can each change the answer.
- Read the reasons and the source. Each result explains why and links to the rule it used. Save or screenshot it and bring it with you when you call or email your building department.
Small trade jobs the model code exempts
Besides the building exemptions above, the model code lists a short set of electrical, gas, mechanical, and plumbing jobs that do not need a permit. A city that publishes its adopted list, such as Eureka, California, includes items like these (also see IRC R105.2):
- Electrical: listed cord-and-plug temporary decorative lighting, reinstalling plug receptacles (but not new outlets), replacing a breaker or fuse of the required capacity in the same location, and minor repairs such as replacing lamps.
- Gas: portable heating, cooking, or clothes-drying appliances, and replacing a minor part that does not change the equipment's approval or make it unsafe.
- Mechanical: portable heaters, portable ventilation and cooling units, and portable evaporative coolers.
- Plumbing: stopping leaks and clearing stoppages, and removing and reinstalling a toilet, as long as no valves, pipes, or fixtures are replaced or rearranged. If a concealed pipe has to be removed and replaced with new material, that counts as new work and needs a permit.
Repairs that still need a permit
People often assume "it's just a repair" means no permit. The model code's ordinary-repair rule is narrower than that. It does not cover cutting away a wall or partition, cutting or removing a structural beam or load-bearing support, changing a required exit, or adding, altering, replacing, or relocating water, sewer, drain, gas, or vent piping, electrical wiring, or mechanical work affecting health and safety (IRC R105.2.2). Replacing a section of drain pipe inside a wall or adding a circuit falls on the permit side of that line.
Emergencies are handled separately. Under Eureka's published list, when equipment has to be replaced or repaired in an emergency, the permit application is due within the next working business day (R105.2.1). Our emergency repair permits guide covers what to do after a leak or storm.
Your city's list may be shorter, or missing
The exemption list is a starting point that local governments can edit. Two published examples:
- Eureka, California lists one-story detached accessory structures up to 120 square feet, not the 200 square feet in the IRC model list (Eureka R105.2).
- Frankfort, Illinois deleted Section R105.2 from its adopted residential code for building, electrical, gas, and mechanical work, so the model exemptions do not carry over there (Frankfort Code § 150.20(C)).
That is why a "likely no permit" result for "Other U.S. city or county" should always be confirmed locally.
When to call your local office before you start
- The checker says "check locally", or your project sits right at a size or height limit.
- The work touches structure, an exit, wiring, gas, or concealed plumbing.
- The property is in a historic district, a flood zone, or near an easement or property line.
- Your city is not one of the researched cities above and you have not found its exemption list online.
- You plan to sell or refinance soon and want a written record that no permit was needed.
Project guides
For the full rules behind the most common results, see our guides to deck permits, shed permits, and fence permits.
