NYC Certificate of Occupancy: Temporary vs. Final, Change-of-Use, and When You Need a New One
9 min read · Updated 2025-01-15
NYC Certificate of Occupancy guide: the difference between TCO and final CO, when a change of use requires a new CO, how to apply through DOB NOW, and common obstacles.
Certificate of Occupancy Basics
What is a Certificate of Occupancy (CO) in NYC?
A Certificate of Occupancy (CO) is a document issued by the NYC Department of Buildings that certifies a building or space is legal and safe for its designated use. Every building in NYC must have a CO. It specifies the legal occupancy (e.g., residential multiple dwelling, commercial office, mixed-use), the number of dwelling units, and other key building characteristics. Without a valid CO, a building cannot legally be occupied, leased, or sold.
What is a Temporary Certificate of Occupancy (TCO)?
A Temporary Certificate of Occupancy (TCO) allows occupancy of a building or portion of a building before all work is complete or all sign-offs are obtained. TCOs are common in construction projects where, for example, lower floors are complete and ready for occupancy while upper floors are still being finished. TCOs are valid for 90 days but can be renewed. However, indefinite TCO renewal is not acceptable — ultimately, a final CO must be obtained. Mortgage lenders and buyers often require a final CO, not just a TCO.
What is the difference between a TCO and a final CO?
A final CO means all construction work is complete, all required inspections have been passed, all special inspections are signed off, all required permits are closed, and DOB has issued permanent occupancy status. A TCO is a temporary authorization while work remains in progress. The distinction matters for financing (some lenders won't fund on a TCO), sales (buyers want certainty of legal occupancy), and insurance. Chasing a final CO is a critical final step in any construction project.
When do I need a new Certificate of Occupancy?
You need a new or amended CO when you change the legal use of a space (e.g., converting a commercial building to residential), add a new dwelling unit, change the number of floors, or make major structural alterations that affect the building's legal occupancy. Converting a basement from storage to habitable space, for example, requires amending the CO. Renovations that don't change the use, number of units, or structure typically don't require a new CO — just building permits.
How do I apply for a new CO or amended CO?
Applications for CO amendments or new COs are filed through DOB NOW: Build as part of the permit and job application process. A licensed PE or RA prepares and files the plans. DOB reviews the plans (either through standard plan examination or professional certification), issues the permit, the work is done, inspections are passed, and finally DOB issues the CO. The timeline can range from a few months to several years depending on the project's complexity and DOB's workload.
What is a Letter of No Objection (LNO) and when is it used?
A Letter of No Objection (LNO) is a DOB document stating that DOB has no objection to a particular use being conducted in a space that doesn't have a CO specifically authorizing that use. LNOs are used for certain limited situations — like confirming that a ground-floor retail use is permitted in a commercial building where the CO predates modern use designations. LNOs are not a substitute for a CO and have limits on what they can authorize.
Can I sell a property without a CO?
Properties must have a CO (or LNO) to be legally sold with proper title insurance. A building with work done without permits or with an outdated CO presents title issues. Buyers' attorneys and lenders will flag CO problems in due diligence. While a sale might technically close with a CO issue, it creates risk for the buyer and typically results in a price reduction or a seller-funded escrow to cover the cost of resolving the CO. Addressing CO issues before listing is always preferable.
What common obstacles prevent getting a final CO?
Common obstacles include: open permits on the property that haven't been signed off (a common issue from prior owners), outstanding DOB violations, failed inspections, missing special inspection reports, incomplete utility sign-offs, or unresolved HPD violations. Sometimes a property has a "grandfather" issue — work done decades ago without permits that now needs to be legalized before a new CO can be issued. A title search and DOB records search before purchasing a property can surface these issues early.
How do I look up the existing CO for a property?
You can look up a property's Certificate of Occupancy through the DOB BIS Web portal (a810-bisweb.nyc.gov) using the building's BBL or address. The portal shows the current CO or LNO and the occupancy classification. You can also access detailed property records through DOB NOW. If the building is very old (pre-1938), it may predate the CO requirement and have a "pre-CO" classification.