What Is a Certificate of Occupancy?

A certificate of occupancy, usually shortened to CO, is the document that formally allows a building to be used. It is issued by the local building official once the work covered by the permit has passed its inspections and complies with the approved plans and adopted codes. For new homes, it is the last step of the permit process and is often a condition of closing a mortgage.

Despite the importance, many homeowners never see one. Most residential permits are for remodels, replacements, and repairs, which usually end with a final inspection rather than a new CO. Understanding the difference helps when you are buying, selling, financing, or converting a property.

What the building code says

The model International Residential Code (IRC), in Section R110.1, says a building or structure shall not be used or occupied, and a change in the existing use or occupancy shall not be made, until the building official has issued a certificate of occupancy. The model code includes two notable exceptions: work that is exempt from permits under Section R105.2, and accessory buildings or structures such as detached garages and sheds. The International Building Code (IBC) contains the same rule in Section 111.1 for commercial and multifamily buildings.

Under IRC R110.3, the CO is issued after the building official inspects the building and finds no violations, and it must show:

• The permit number
• The address of the structure
• The name and address of the owner or the owner’s authorized agent
• A description of the portion of the structure covered
• A statement that the described portion has been inspected for compliance with the code
• The name of the building official
• The edition of the code under which the permit was issued
• Whether an automatic sprinkler system is provided and whether it is required
• Any special stipulations and conditions of the building permit

States and cities adopt these provisions with amendments, so the exact triggers and format differ locally.

When you usually need a CO

• New homes and other new buildings. This is the most common case.
• Change of use or occupancy. Converting a house to an office, a warehouse to apartments, or a retail space to a restaurant typically requires a new CO, because different occupancies carry different code requirements.
• New dwelling units. Adding an accessory dwelling unit or converting a single-family home to a duplex usually requires a CO for the new unit in many jurisdictions. See Do I need a permit for an ADU?.
• Additions, in some jurisdictions. Others treat additions like remodels and close them with a final inspection.
• Commercial tenant spaces. A new tenant or change of tenant layout often requires a new CO even when the building already has one.

When a final inspection is usually enough

For most residential alterations, such as kitchens, bathrooms, basement finishes, reroofs, decks, and equipment replacements, the permit closes with a passed final inspection. The permit record will show the work as finaled, approved, or complete. Some departments issue a certificate of completion or a final approval letter for these projects. Keep that documentation with your property records, because it is what a buyer or lender will ask to see.

How to get a certificate of occupancy

1. Pass every required inspection. The final building inspection comes last, after the trade finals. See building inspection stages.
2. Obtain sign-offs from other departments. Depending on the project and jurisdiction, these can include zoning, fire, public works, health (for septic or wells), and utilities.
3. Submit required documents. Common examples are a final elevation certificate in flood zones, energy test reports, special inspection reports for engineered work, and as-built surveys.
4. Pay any outstanding fees, including impact fees that some jurisdictions collect at CO rather than at permit issuance.
5. Request the CO if the department does not issue it automatically. Many departments issue it through the permit portal once all holds are cleared.

How the rules differ by city

Whether a house ever gets a CO depends heavily on the city. Four examples from official sources:

• New York City. The Department of Buildings requires a CO for every new building and a current or amended CO when a change affects use, egress, or type of occupancy. No one may legally occupy a building until DOB issues a CO or temporary CO, and a CO has no expiration date. Before issuing one, DOB requires final construction, plumbing, electrical, and (where present) elevator sign-offs, a final building survey, a final Builders Pavement Plan, no open applications or violations, a PW3 cost affidavit, and an approved schedule of occupancy in DOB NOW: Build. Minor alterations close with a Letter of Completion instead. Buildings built before January 1, 1938, when a CO was generally not required, can get a Letter of No Objection confirming their legal use. COs requested on or after March 1, 2021 are searchable in DOB NOW; older ones are in the Buildings Information System.
• San Diego. Information Bulletin 585 (August 2026) says the city issues COs for new nonresidential and multiple-dwelling-unit buildings, tenant improvements in shell buildings, and changes of occupancy classification. It does not issue a CO for single-dwelling units, duplexes, townhomes, private garages and sheds, remodels that do not change occupancy, or a change of ownership or tenancy, even when a lender asks for one. For those projects, the finaled permit is the record.
• Phoenix. A CofO is required for new commercial and residential structures, tenant improvements of newly occupied space, and remodels that change the occupancy type. Once all required inspections pass, the CofO is generated automatically. Projects that do not need a new CofO receive a green tag showing compliance. The city has an online certificate search, and a public records request for an existing CofO typically takes three to five business days.
• Denver. The city’s development fee schedule lists a temporary certificate of occupancy at $200 and a duplicate certificate of occupancy or compliance at $25, a reminder that a TCO is a separate, paid request rather than an automatic step.

Temporary certificates of occupancy

IRC R110.4 allows the building official to issue a temporary certificate of occupancy before the work is complete, as long as the portions to be occupied can be used safely, and requires the building official to set the period during which it is valid. A temporary CO is common when landscaping, driveway paving, or exterior finishes are delayed by weather. It sets a time limit and may come with conditions. Ask whether a fee or a bond is required, and track the expiration date, because occupying a building after a temporary CO expires can put you out of compliance.

Buying or selling: checking for a CO

When buying a home, especially new construction or a property with an addition, finished basement, or rental unit, ask for the CO or the final inspection records. You can also request the permit history directly from the building department or search its online records.

Keep in mind:

• Many older homes have no CO on file because the jurisdiction did not issue them, or did not retain records, when the house was built. That alone is not a red flag.
• A home whose current use differs from its CO, such as a garage converted to living space or a basement apartment that the records do not show, suggests unpermitted work. See unpermitted work.
• Some municipalities require a resale inspection or a certificate of continued occupancy before a property changes hands. Ask the local department or your real estate attorney.
• Lenders financing new construction typically require a CO or equivalent final approval before closing.

If a CO is denied or delayed

The department will tell you what is outstanding. Common holdups are an unpassed trade final, a missing elevation certificate or energy test, an unpaid fee, or a sign-off from another department. If you disagree with a code interpretation, IRC Section R112 provides for a board of appeals.

CO checklist

• Permit card showing every required inspection signed off, including trade finals
• Sign-offs from zoning, fire, public works, health (septic or well), and utilities where they apply
• Final elevation certificate if the site is in a flood hazard area (IRC R109.1.6.1)
• Energy test reports, such as blower-door and duct leakage results, where your energy code requires them
• Special inspection or engineer letters for engineered elements
• As-built or final survey if the department requires one
• Proof that impact, utility connection, and any outstanding permit fees are paid
• For a TCO: a written list of incomplete items, the requested time period, and any fee or bond the department charges

Questions to ask your building department

• Does my project result in a CO, a certificate of completion, or only a final inspection?
• Which other departments must sign off before the CO is issued?
• What documents do you need before final, such as elevation certificates or test reports?
• Do you issue temporary COs, and what are the conditions and time limits?
• How can I get copies of a CO or permit history for a property?

To request records or schedule a final, find your local building department.