A building permit is the local government's way of making sure certain work meets safety codes, and of keeping a record that the work was done. Whether you need one depends on where you live and what you are doing, so the only reliable answer comes from your own city or county. This guide explains how permits generally work and where to check.
Why permits exist
Codes cover things that can hurt people or damage neighbors' property when they are done badly: electrical wiring, gas, structural changes, plumbing and drainage, and anything that affects fire safety. A permit lets an inspector check the work at the right stage, and leaves a record that it was done to code.
Jobs that commonly need a permit
Rules differ, but these are the kinds of work that often require one:
- Replacing a water heater, especially when the fuel or venting changes.
- Gas line work, new gas appliances and furnace or boiler replacement.
- Electrical work beyond simple swaps, such as a new circuit, a panel upgrade, a generator or an EV charger.
- Structural changes, including moving or removing walls, new openings and foundation work.
- Re-roofing in many places, and window or door replacement when the opening changes size.
- Sewer, septic and well work.
- Fences, decks and retaining walls above a certain height, which varies by place.
- Additions, finished basements and garage conversions.
Jobs that often do not
Cosmetic work usually does not need one, such as painting, flooring, countertops and ordinary repairs that do not change systems or structure. Even so, rules differ, so check before you assume.
Who pulls the permit
In most cases the licensed contractor applies for the permit and the fee appears in the quote. Some places let homeowners pull permits for work on their own home, usually with limits and sometimes with a test or a signed statement. Either way, ask who is responsible, and make sure the cost is a line in the quote, not a surprise. Homeowners associations and historic districts can have their own approval rules in addition to the city.
What can go wrong without one
- Insurance. An insurer may question a claim for damage connected to unpermitted work.
- Selling. Unpermitted work may need to be disclosed, and buyers or lenders may ask for it to be corrected or inspected.
- Fines and tear-out. A city can issue a fine or require opened walls and redone work if the problem is discovered.
- Safety. The inspection is the second pair of eyes on work that is hard to see once the walls are closed.
How to find out what you need
- Search for your city or county building department's website. Many list which projects need a permit.
- If the website is unclear, call or visit and describe the exact job: what is being replaced, in the same place or a new one, and with what.
- Ask about the fee, how the inspection is scheduled and how long approval usually takes.
- Check separately with your homeowners association, if you have one.
- Keep the approved permit and the final inspection sign-off with your house records.
What permits cost
Fees vary widely by city and often depend on the value or type of the job. The table shows permit fee ranges cited by the sources behind our calculators for the projects where we found a quoted range. Treat them as a guide, not a quote. Your local fee may be lower, higher, or not required at all.
| Project | Permit fee cited | Sources |
|---|---|---|
| AC unit | $100–$500 | HVAC Project Cost |
| Bathroom remodel | $100–$1,000 | Angi, Block Renovation, Fixr |
| Boiler replacement | $50–$300 | Angi |
| Electrical panel replacement | $50–$350 | Inch Calculator, Fixr, Bob Vila |
| Fence installation | $20–$200 | HomeAdvisor, Inch Calculator |
| Foundation repair | $100–$400 | This Old House |
| Front door replacement | $0–$100 | One and Done Prep |
| Furnace replacement | $80–$500 | UniColorado, HVAC Project Cost |
| Mini-split installation | $250–$400 | Angi |
| Retaining wall | $50–$450 | HomeGuide, Angi, LawnStarter |
| Roof replacement | $150–$500 | ShinglesCalculator |
| Tankless water heater | $25–$300 | Angi |
| Tree removal | $60–$150 | Angi, Fixr |
| Water heater replacement | $25–$300 | Angi |
| Water softener | $50–$150 | Empire Home Protect, HomeBuddy |
| Window replacement | $80–$300 | WindowPriceCalc, Angi |
Where a calculator includes a permit line, you can switch it on or off. When you compare quotes, check whether the permit is included, using the quote comparison sheet.