Certificate of Occupancy (CO)

No new building may be occupied until the building official issues one, according to the building code (the 2018 International Residential Code, Section R110). That document is the Certificate of Occupancy, or CO, the official green light to live in or use a building. It is the legal proof that your home passed its final inspections and meets the code in force when the permit was pulled.

You get a CO at the very end of construction, after every required inspection passes: footing, framing, plumbing, electrical, mechanical, and the final walkthrough. The AHJ, your city or county building department, sends an inspector for the final check. When the inspector confirms the home is safe, weather-tight, and complete, the office issues the CO. Only then can you legally move in, set up utilities permanently, or close on a sale.

For example, a custom home in Gilbert might pass framing and electrical but fail the final because the smoke detectors are not hardwired or the address numbers are not posted. The builder fixes those items, calls for re-inspection, and the CO follows. Lenders often hold the last draw until the CO is in hand, so it also affects when the final payment releases.

Some jurisdictions issue a Temporary Certificate of Occupancy (TCO) when the home is livable but a few minor items remain, such as final landscaping or a punch-list repair. A TCO lets you move in with a deadline to finish. We treat the CO as the true finish line of a build, because until the local office signs it, the home is not legally done no matter how complete it looks.