What Is a Certificate of Occupancy?
By Wyatt Cooper · Published · 3 min read
Key takeaways
- A certificate of occupancy is issued by the local building department, not by the owner or architect, once final inspections are passed.
- Building departments generally bar occupancy of a new building, or one whose use or occupancy changes, until they issue a CO or temporary CO; New York City states it outright.
- A temporary CO allows limited occupancy for a set period while remaining items are finished; the rules are local.
A certificate of occupancy (CO) is the document a local building department issues stating that a building, or part of one, may legally be used and occupied for a stated use, after final inspections show it complies with the approved plans and codes. A temporary certificate allows limited occupancy while remaining items are finished.
What a certificate of occupancy does
New York City's building department puts it in one line: "A Certificate of Occupancy (CO) states a legal use and/or type of permitted occupancy of a building." New buildings must have one, existing buildings need a current or amended CO "when there is a change in use, egress or type of occupancy", and "No one may legally occupy a building until the Department has issued a CO or Temporary Certificate of Occupancy (TCO)" (NYC Department of Buildings). Other jurisdictions issue certificates under the building code they adopt, each with its own process.
A temporary CO is narrower. Roseville, California, for example, treats it as an accommodation: the request must come in writing at least 30 days ahead, minimum health and safety items must be complete, uses considered are things like "stocking of shelves or training of employees", and "No building will be opened to the public under a T.C.O." (City of Roseville). Other cities allow more; ask your building department early.
CO vs. substantial completion vs. final completion
| Milestone | Who decides | What it means |
|---|---|---|
| Certificate of occupancy | Building department | The building may legally be occupied for its use |
| Substantial completion | Architect and owner, under the contract | The owner can use the work for its purpose; warranties often start |
| Final completion | Architect and owner | Punch list and closeout done; final payment due |
A CO is often a condition of substantial completion in the contract, but they are different things: one is a government permit, the other a contract milestone. How the contract milestone is decided is in how to determine substantial completion. The punch list and the closeout package usually follow the CO.
Example
Retail fit-out, suite 120
- Final building, fire and electrical inspections passed
- April 12
- Temporary CO, for stocking and staff training only
- Requested March 10, issued April 13
- Remaining item
- Exterior sign lighting
- Certificate of occupancy
- Issued April 27
- Store opens to the public
- May 1
The TCO request went in 34 days before it was issued (March 10 to April 13: 21 days left in March plus 13 in April), inside a 30-day minimum like Roseville's.
The bottom line
A certificate of occupancy is the building department's permission to use the building, and nobody moves in without it.
Schedule the final inspections early, know your city's temporary CO rules, and do not confuse the CO with the contract's completion dates. Conflo is built for commercial work today.
Sources
- Certificate of Occupancy — NYC Department of Buildings. Read October 22, 2026.
- Temporary Certificate of Occupancy (policy summary) — City of Roseville, Development Services, Building Division. Read October 22, 2026.
Questions
Who issues a certificate of occupancy?
The local building department (the building official), after the required final inspections are passed.
Do renovations need a new certificate of occupancy?
Often, when the use, egress or type of occupancy changes, as in New York City. Smaller alterations may need only a final inspection. Ask your building department.
What is a temporary certificate of occupancy?
A time-limited approval to occupy all or part of a building before every item is complete, on conditions the building department sets.
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