A building permit is permission from your city or county to do regulated work. It comes with inspections, where a trained inspector checks the work at key points against the adopted building code. Permits protect you: an unpermitted job can cause problems when you sell, refinance or file an insurance claim, and nobody independent checked the hidden work.
In most places the licensed contractor pulls the permit in their own name. Be cautious if a contractor asks you to pull it as an 'owner-builder' for work they are doing - that can shift responsibility to you.
Usually needs a permit
Structural changes: additions, removing or moving walls, new windows/doors in new openings
Most electrical work beyond like-for-like device replacement
Water heaters, repipes, new drains, moving fixtures
HVAC equipment replacement (mechanical permit)
Re-roofing in many jurisdictions
Attached or raised decks, patio covers, larger retaining walls
Garage conversions, ADUs, pools and spas
Often exempt (check locally)
The model International Residential Code (2021 IRC, section R105.2) lists some work that does not need a building permit, including: one-story detached accessory buildings up to 200 sq ft, fences up to 7 ft, retaining walls up to 4 ft that don't hold back extra load, sidewalks and driveways, painting, papering, tiling, carpeting, cabinets, countertops and similar finish work, and small freestanding decks (under 200 sq ft, 30 in or less above grade, not attached to the house). Cities and counties adopt and amend the code, so your local rules may be stricter - and exempt work still has to meet code.
Typical inspection points
Footing / foundation - before concrete is poured
Underground or under-slab plumbing and electrical - before backfill or pour
Framing and rough-ins (electrical, plumbing, mechanical) - before insulation and drywall
Insulation / energy - before drywall
Drywall or fire-rated assemblies (some jurisdictions)
Final - everything complete and safe; some projects get a certificate of occupancy
Tip: ask your contractor to text you a photo of each passed inspection card or the online inspection result.
Mohave County / local example
In unincorporated Mohave County, residential permits go through Mohave County Development Services, which publishes permitting information and residential/manufactured home permit time frames online. Cities (such as Bullhead City, Kingman or Lake Havasu City) run their own building departments. Always confirm who has jurisdiction for your address.
External sites open in a new tab; Corky's MHS™ is not affiliated with them. Statutes and agency pages change - check the current version.
Please note
Educational information only - not legal, engineering or code advice. Rules vary by state, county and city, and change over time. Check with your local building department and licensing board, and read your own contract.
Want a pro to look it over?
Corky has nearly 25 years as a general contractor across every trade. Send a bid for a Second Look Review (from $25) or ask a quick question at the Contractor's Desk ($5).