Do You Need a Building Permit? A Quick Guide

This guide is general information, not legal advice. Laws vary by state and city — check your local rules or speak to a licensed attorney for your situation.

Permits feel like bureaucracy right up until the moment they matter: when a buyer’s inspector spots a basement bedroom that never appears in the county records, or when an insurer asks who wired the circuit that caught fire. Skipping one rarely causes trouble on the day of the project. It causes trouble years later, usually at the worst possible moment.

The good news is that the rules are less mysterious than they look. Most US cities and counties base their residential rules on the International Residential Code (IRC), then amend it locally. That means the broad pattern — structural, electrical, plumbing and mechanical work needs a permit; surface finishes usually do not — holds in most places, even though the exact thresholds differ. This is the version we use for planning projects at HomePlusDeals.Com.

What usually needs a permit

If the work changes how the house stands up, how it is powered, how water and waste move through it, or how it is heated and ventilated, assume a permit until your building department tells you otherwise.

• Structural changes. Removing or altering walls (especially load-bearing ones), adding rooms, finishing a basement into living space, cutting new window or door openings, and most additions.
• New electrical circuits and wiring. Adding circuits, moving outlets, installing a subpanel, upgrading service, or wiring an EV charger.
• Plumbing changes. Moving or adding fixtures, new supply or drain lines, and in many jurisdictions replacing a water heater.
• HVAC work. Installing or replacing a furnace, heat pump or central air system, adding ductwork, and gas line work.
• Decks. Particularly anything attached to the house, raised more than about 30 inches, or serving an exit door. Our patio vs deck cost comparison covers why decks usually carry permit and inspection costs that patios often avoid.
• Fences over a set height, and almost any fence near a property line, pool or corner lot (zoning rules often apply even when a building permit does not).
• Roofing. Many jurisdictions require a permit for a full re-roof or for structural roof repairs, even when small patch repairs are exempt.
• Windows, siding and skylights in some places, especially where openings change size or energy-code rules apply.

What usually does not

The model code exempts a list of minor work. Federal Way, Washington publishes a clear example of how a city adopts that list in its residential permit exemptions page. Typical exemptions include:

• Painting, papering, tiling, carpeting, cabinets, counter tops and similar finish work.
• Small, low, detached decks — in that city’s version, not over 200 square feet, not more than 30 inches above grade, not attached to the house and not serving the required exit door.
• One-story detached accessory structures up to 200 square feet.
• Fences under a height limit (6 feet in Federal Way’s version; other editions and cities use different limits).
• Retaining walls up to 4 feet, measured from the bottom of the footing, unless they support a surcharge.
• Minor electrical repairs such as replacing lamps, and wiring operating at less than 25 volts and not more than 50 watts.
• Stopping leaks and clearing stoppages in drains and pipes — but replacing concealed piping is treated as new work.
• Portable heating and cooling units.

Two cautions. First, the same page notes that separate permits may still be required for some exempt items, and the code itself says an exemption does not authorise work that violates other laws. Second, exemptions vary: some jurisdictions treat a cabinet swap that changes the kitchen layout differently from a straight replacement.

Common projects at a glance

The thermostat line is a good example of how the exemptions play out. Standard thermostats run on 24-volt control wiring, which is why a swap is typically homeowner work — the wiring details are in our smart thermostat buying guide. Replacing the furnace that thermostat controls is a different story.

How to check with your local building department

1. Find the right office. Search for your city name plus “building permits.” If you live in an unincorporated area, it is usually the county. Some states also run their own electrical or plumbing licensing programs.
2. Look for an exemption list or “do I need a permit” page. Many departments publish one, like the Federal Way example above.
3. Call or email the permit counter with a short description: what you are changing, the size, and whether it touches structure, wiring, plumbing or gas. Ask for the answer in writing if the project is borderline.
4. Ask who can pull the permit. Some places let homeowners pull permits for work on their own home; others require a licensed contractor for electrical, plumbing or gas.
5. Ask about inspections. Most permits involve at least a rough-in inspection (before walls are closed) and a final. Do not close up walls before rough-in is signed off.
6. Check zoning separately. Setbacks, height limits, lot coverage and historic district rules are often handled by a different office than building permits.

If you hire a contractor, the permit is normally their job, and its cost should be on the quote. A contractor who suggests skipping it to save money is telling you something about how they work. Our kitchen remodel cost guide explains where permit fees typically sit in a renovation budget.

The risks of unpermitted work

None of these is automatic, and outcomes depend on your state, insurer and local department. But the pattern is consistent: the cost of a permit is small and known, while the cost of an unpermitted project surfaces later and is unpredictable. If you bought a house with unpermitted work, many departments have a process for legalising it after the fact, which usually involves inspection and, sometimes, exposing parts of the work.

If something does go wrong — a fire, a leak, a collapse — the claims process is covered in our homeowners insurance claim guide.

HOA approval is a separate thing

A building permit says your project meets the building code. It says nothing about whether your homeowners association allows it. HOAs enforce their own covenants, conditions and restrictions (CC&Rs), which can cover fence styles, exterior colors, roofing materials, decks, solar panels and more, and many require architectural committee approval before work begins.

You may need both, and getting one does not guarantee the other. Read your CC&Rs, submit the HOA application early, and do not assume a city permit overrides an HOA rule. Some states limit what HOAs can restrict for certain items, such as solar installations, so check your state’s rules if a denial seems unreasonable.

Renters are in a different position entirely: alterations generally need the landlord’s permission, and the landlord is normally responsible for code-required repairs — see our guide to renters’ rights for repairs.

Quick checklist

• Does the work touch structure, wiring, plumbing, gas or HVAC? Assume a permit.
• Is it surface finish work only? Probably exempt — confirm with your local list.
• Check your city or county exemption page, then call the permit counter if unsure.
• Confirm who is allowed to pull the permit and how inspections are scheduled.
• Check zoning setbacks and HOA rules separately.
• Keep permits, inspection sign-offs and contractor invoices with your home records.
• For appliances and smart devices you install, keep warranty paperwork too — see product warranty rights.

The bottom line

When in doubt, ask. A five-minute call to the building department costs nothing, and a written “no permit needed” is worth keeping in the same folder as your receipts. Browse the rest of our legal guides for related questions — the HomePlusDeals.Com approach is the same throughout: check the boring rules first, then spend the money.