Your authority is local. Find them.

The authority having jurisdiction (AHJ) is the agency that adopts, enforces, and inspects the building codes where you live. For most homeowners that’s a city or county building department, but it may also include the fire marshal, the health department for septic work, the public utility for water and gas tie-ins, or an HOA for everything visible from the street.

How to find your AHJ

1. Search “[your city or county] building department”. Most jurisdictions list permitting, inspections, and licensure on a single page.
2. If your city is unincorporated, the county department is usually the AHJ.
3. For gas, water, and electrical service tie-ins, the utility may also have its own approval process separate from the city.
4. For multifamily, condo, or HOA properties, the HOA has its own approval process for exterior changes — this is in addition to, not instead of, city permits.

What to ask before work starts

• Does this work require a permit? Which type?
• Does the contractor need a specific license for this scope?
• Who pulls the permit — the contractor or the homeowner?
• What inspections are required, in what order?
• What edition of the code is currently adopted? (Codes update on a 3-year cycle, but adoption lags.)
• Are there any local amendments to the standard code?
• What does the permit cost? What does an inspection cost?
• What’s the typical permit turnaround time?

Why permits protect you

A permitted job has an independent third party (the inspector) verifying the work. That inspection becomes part of the public record on your property. When you sell the house, the absence of permits on regulated work shows up in due diligence and can break the deal — or cost you to retroactively legalize.

A contractor who suggests skipping the permit is shifting their liability to you. The permit is the cheapest insurance you’ll buy on the project.

Common work that triggers a permit

• Most electrical work beyond replacing a fixture or like-for-like switch.
• Plumbing changes that re-route waste or supply lines.
• Water heater replacement (almost everywhere).
• HVAC system replacement.
• Structural changes — moving walls, adding openings, changing roof load.
• Re-roofing (sometimes — depends on jurisdiction).
• Window or door replacement that changes the opening size.
• Decks, fences over a certain height, accessory structures.
• Anything related to gas appliances or gas lines.
• Anything that crosses the property line (sidewalks, curb cuts, sewer ties).

This list is illustrative, not definitive. Your jurisdiction adopts its own rules. Always verify with the AHJ.