Building Permits 101: When You Need One, How to Get One, and What It Costs

You're planning a home project. Before you pick up a hammer or hire a contractor, there's one question that can save you thousands of dollars and months of headache: do I need a building permit? Here's everything you need to know, in plain English.

What a building permit actually is

A building permit is official approval from your city or county government to proceed with a construction project. It's not just a fee — it's a safety check. When you pull a permit, the building department reviews your plans to make sure the work meets building codes (safety standards for structures, electrical, plumbing, and mechanical systems). During construction, inspectors verify the work at critical stages.

The system exists because construction mistakes can kill people. Improperly wired electrical can cause fires. Bad structural work can collapse. Incorrect plumbing can contaminate water. Building codes are the accumulated lessons from every construction disaster in history, and permits are how cities enforce them.

When you need a permit (and when you don't)

Almost always needs a permit:

• Anything structural — removing or modifying load-bearing walls, room additions, new openings in exterior walls
• Electrical work beyond swapping fixtures — new circuits, panel upgrades, running wire
• Plumbing changes — moving fixtures, adding bathrooms, water heater replacement (in most cities)
• HVAC installation or replacement — furnaces, central air, ductwork
• Decks over a certain size (usually 200 sq ft) or height (usually 30” above grade)
• Finishing a basement or attic as living space
• Roofing (in many cities) and siding replacement
• Fences over a certain height (usually 6–7 feet)
• Swimming pools, ADUs, garages, sheds over a certain size

Usually doesn't need a permit:

• Painting, wallpaper, flooring, carpeting
• Replacing cabinets, countertops, hardware
• Replacing fixtures (faucets, light fixtures, outlets) in the same location
• Landscaping that doesn't involve grading or retaining walls
• Minor repairs (patching drywall, fixing a leaky faucet)

What a building permit costs

Permit fees are based on your project's scope and your city's fee schedule. Most cities charge 1–2% of total project value.

Many cities also charge a separate plan review fee (often 50–65% of the permit fee). Some charge technology fees, impact fees, or school district fees on larger projects. Budget 3–5% of your total project cost for all permit-related expenses to be safe.

How to get a building permit, step by step

1. Find your building department. Search “[your city] building department” or “[your county] building permits.” Most have websites with application forms and fee schedules.
2. Figure out which permits you need. A kitchen remodel might need a building permit, electrical permit, plumbing permit, and mechanical permit — each filed separately. Call the building department if you're unsure.
3. Prepare your application. Simple projects (water heater, fence) may just need a basic form. Larger projects require a site plan, construction drawings, and sometimes stamped engineering plans.
4. Submit and pay. Many cities accept online applications. Others require in-person submission. Pay the permit fee and plan review fee at this stage.
5. Wait for plan review. Simple “over the counter” permits can be issued same-day. Projects requiring plan review take 1–6 weeks. Complex projects may need 2–3 months.
6. Address any corrections. First-round plan review corrections are common and normal. Respond promptly to keep things moving.
7. Post your permit. Once issued, display the permit card at the job site in a visible location.
8. Schedule inspections. Call for inspections at required stages (foundation, framing, rough electrical/plumbing, insulation, final). Never cover up work before the inspector signs off.
9. Get your final approval. After passing final inspection, you'll receive a final sign-off or Certificate of Occupancy.

Types of building permits

Most homeowners think “building permit” is one thing. It's actually a category:

• Building permit: Covers structural work — framing, foundations, load-bearing modifications
• Electrical permit: New circuits, panel upgrades, rewiring. Usually requires a licensed electrician (or a homeowner pulling an owner-builder permit)
• Plumbing permit: Moving or adding fixtures, water heater replacement, gas lines. Usually requires a licensed plumber.
• Mechanical permit: HVAC installation, ductwork, ventilation systems
• Demolition permit: Tearing down structures
• Grading permit: Earthwork, drainage changes, retaining walls

A single renovation project often requires multiple permit types. Your contractor should know which ones are needed, but it's worth verifying yourself.

Certificate of Occupancy

A Certificate of Occupancy (CO) is issued after all permitted work passes final inspection. It confirms the building is safe to occupy. You need a new CO when:

• Building a new home
• Converting space to a different use (garage to living space, adding an ADU)
• Some cities require a CO at point of sale

An open permit (work started but never got final inspection) is a red flag. It means the work was never verified as safe. If you're buying a home, check for open permits — they become your problem after closing.

Common permit myths

“Small projects don't need permits.” Size thresholds exist, but they're smaller than most people think. Many cities require permits for any deck, any electrical work beyond replacing a fixture, and any plumbing beyond replacing a faucet.

“Interior work doesn't need permits.” Wrong. Electrical, plumbing, and structural changes need permits regardless of whether they're interior or exterior. Finishing a basement is interior work that almost always requires a permit.

“My contractor will handle the permits.” Good contractors do. But it's your house and your liability. Ask to see the actual permit. Some less-scrupulous contractors say they'll pull permits and never do.

“Nobody will ever know.” Neighbors report unpermitted work. Insurance adjusters check permits after claims. Buyers and their inspectors check permit records. Cities compare aerial photos to permit records. It comes out.

“I can always get a retroactive permit.” Usually true, but it costs 2–4 times more, and you may need to tear out finished work so inspectors can see behind the walls. Doing it right the first time is always cheaper.

What happens if you skip the permit

The consequences are real and expensive:

• Fines: $500–$10,000+ depending on jurisdiction and severity
• Stop-work orders: Your project halts until you get the permit
• Forced demolition: In worst cases, you tear out and redo the work
• Insurance denial: If unpermitted electrical causes a fire, your claim may be denied
• Sale complications: Buyers discover unpermitted work during inspections, leading to price reductions or killed deals
• Reduced home value: Appraisers may not count unpermitted square footage

The permit fee is almost always the cheapest part of any project. A $200 permit protects a $20,000 investment.

Frequently Asked Questions

Disclaimer: This article provides general educational information about building permits. It is not legal or professional advice. Building codes, requirements, and fees vary by jurisdiction and change frequently. Always verify requirements with your local building department before starting any project.