A certificate of occupancy, often called a CO, is a building department's document identifying a building's approved use and occupancy. Where one is required, it confirms that the applicable requirements for that occupancy have been met. It may apply to an entire building or a specified portion.
The distinction matters when a listing advertises a second apartment or a finished commercial conversion. Find out what the city approved before counting on that use. But a missing certificate alone is a poor shortcut: some properties never required one.
This is part of the building code violations guide. Start with the rule for the property, then check its records.
A building permit and a certificate of occupancy do different jobs
A permit gives permission to perform specified work. Occupancy approval addresses how the completed space may be used. The documents fit together, but one doesn't automatically stand in for the other.
| Record | What it establishes | What to read carefully |
|---|---|---|
| Building permit | Approval for the described construction work | Scope, approved plans, conditions, and current status |
| Final inspection approval | Completion of required inspection sign-off for the applicable work | Which permit and trade the sign-off covers |
| Certificate of occupancy | Approved occupancy or use of a building or portion | Unit count or use, covered area, and conditions |
| Temporary certificate of occupancy | Conditional occupancy permission before final completion | Expiration date, covered areas, and unfinished requirements |
An electrical final for a basement does not, by itself, establish that the basement is an approved separate dwelling. Match the approval to the claim you need to verify. Our building permit lookup walkthrough explains how to open the underlying file.
When is a certificate of occupancy required?
Requirements depend on the jurisdiction, building type, and project. New construction and a change in legal use are common reasons to check. Don't assume a sale automatically creates a requirement for a new certificate.
Seattle's addition and alteration permit guidance makes an important distinction: it does not require certificates of occupancy for single-family and duplex projects, but does require a final approved inspection. Ask SDCI which approvals establish the use of the particular property you are reviewing.
Older buildings add another wrinkle. New York City's Department of Buildings says buildings constructed before 1938 generally do not need a CO unless later changes altered their use, egress, or occupancy. The department describes a Letter of No Objection as one way to confirm legal use when appropriate.
Neither example travels automatically across a city line. The Seattle exception does not establish the rule for Tacoma, and New York's 1938 threshold does not establish the rule for Washington.
How to find a certificate of occupancy
Search the city or county building department that governs the address. This is usually a permit-record search rather than a deed search at the recorder.
Start with the address and any known permit number. Then open attachments, inspection history, and issued documents. A permit marked “issued” tells you the project received permission to proceed; keep reading for completion and occupancy records.
If nothing appears, ask the department a specific question: “What record establishes the approved use and number of dwelling units at this address?” Include the parcel number, building, and unit you mean. That request is more useful than insisting on a CO that the jurisdiction never required.
Older records may sit outside the online portal. Our guide to public building permit records explains access limits and how to request the rest of the file.
Save the document itself.
A seller's screenshot of a portal status can leave out the conditions or the part of the building the approval covers.
Temporary occupancy needs a second look
A temporary certificate of occupancy, or TCO, permits occupancy under stated conditions while remaining requirements are completed. It is not a promise that the owner will finish them.
Seattle Fire's construction inspection guidance describes its role in temporary occupancy approvals. Fire-related approval is one part of the process; verify the building department's issued document as well.
NYC's temporary occupancy guidance says its TCOs generally expire after 90 days. Read the actual expiration and conditions wherever the property sits.
For a purchase, list each outstanding item and who will complete it. Obtain estimates for that work before assuming the remaining sign-offs are administrative.
Can you sell a house without a certificate of occupancy?
Sometimes. First establish whether the property requires a certificate at all. Then check local transaction rules and the lender's requirements. A right to transfer ownership and permission to occupy a space answer different questions.
Consider a hypothetical house advertised with a rental basement. The records establish a single dwelling, and the seller supplies a permit for electrical work. That leaves the separate apartment's approval unresolved. Ask the department about the intended use before including rent from a second unit in your numbers.
If a required approval is missing, find out which inspections, plans, or corrections remain. An “as-is” sale does not issue an occupancy approval. Buyers and sellers need an agreement that accounts for the unresolved work and the intended financing.
For lead research, a missing online PDF tells you very little. A documented occupancy violation tells you what the city actually found. You can use the FlaggedLeads map to check available code cases, then request the permit and occupancy records from the building department.
Frequently asked questions
Is a certificate of occupancy the same as a building permit?
No. A building permit authorizes specified work. A certificate of occupancy documents approved occupancy or use where that certificate is required. Inspect the project scope and final approvals together.
Does every Seattle house need a certificate of occupancy?
Seattle's published guidance says single-family and duplex projects do not require certificates of occupancy, but do require a final approved inspection. Confirm the applicable records with SDCI, especially when the present use differs from the approved use.
Does a temporary certificate of occupancy expire?
Yes, temporary occupancy is subject to the issuing jurisdiction's terms and expiration. NYC says TCOs generally expire after 90 days. Use the dates on your property's document and verify any renewal directly with the department.