- A Certificate of Occupancy (CO) describes the legal occupancy, layout, and allowable use of a building
- New construction always requires a CO; existing buildings need an amended CO if use, exits, or occupancy change
- Temporary COs (TCOs) expire 90 days after issuance and must be renewed or replaced with a final CO
- Buildings built before 1938 may be exempt — unless alterations changed use, exits, or occupancy
- A Letter of No Objection (LNO) confirms exemption for pre-1938 buildings; takes 6–8 weeks to obtain
- Insurance carriers check CO before underwriting — mismatches trigger a requirement to update
- You cannot legally occupy or sell a building without a proper CO or applicable exemption
What Does a Certificate of Occupancy Do?
A Certificate of Occupancy is a legal document issued by the NYC Department of Buildings that confirms a building or portion thereof has been inspected and meets all applicable code requirements for the designated occupancy. It specifies the lawful use of the space — residential, commercial, industrial, or a combination — along with the number of dwelling units, allowable occupancy loads, and the configuration of exits.
The CO is not merely a formality. It is the document that legally authorizes people to occupy a building. Without one (or an applicable exemption), occupancy is unlawful. Lenders check CO status before funding mortgages; insurance carriers verify it before underwriting; and buyers’ attorneys review it during due diligence. A mismatch between the CO and actual use is a red flag that must be resolved.
What Are the Types of Certificate of Occupancy in NYC?
| Type | What It Covers | When Required |
|---|---|---|
| Certificate of Occupancy (CO) | Confirms completed building or unit meets code for designated use; does not expire | New construction; change of use, exits, or occupancy in existing buildings |
| Amended Certificate of Occupancy | Updates an existing CO to reflect changes in use, occupancy, or configuration | When alterations change the legal use, number of units, exits, or occupancy load |
| Temporary CO (TCO) | Allows occupancy while minor outstanding items are completed; expires after 90 days | Issued during construction phasing or when minor items remain outstanding before final CO |
| Letter of No Objection (LNO) | Confirms a pre-1938 building is exempt from CO requirement and its current use is legal | For buildings built before 1938 where no CO was ever required and use/exits/occupancy have not changed |
When Do You Need a CO or an Amended CO?
| Situation | CO Required? | Action |
|---|---|---|
| New construction (all buildings) | Yes — always | Obtain CO upon project completion; TCO may be issued during phased occupancy |
| Change of use (e.g., commercial to residential) | Yes — amended CO required | File ALT1 application; obtain amended CO reflecting new use |
| Adding or removing dwelling units | Yes — amended CO required | ALT1 filing; amended CO to reflect new unit count |
| Non-profit, church, senior center, daycare operating in space | Yes — CO must reflect actual use | Obtain amended CO for assembly/institutional use; non-compliance results in violations |
| Building constructed before 1938, use unchanged | Exempt — LNO available | Apply for Letter of No Objection to confirm exemption (6–8 week multi-step process) |
| Pre-1938 building with post-1938 alterations changing use or exits | Yes — exemption lost | Obtain CO reflecting current legal condition; LNO no longer applicable |
| Insurance carrier identifies CO mismatch | Yes — amended CO required | Resolve mismatch with DOB; update CO to reflect actual use before renewal or underwriting |
How Do You Obtain a CO or Letter of No Objection?
| Step | Action | Notes |
|---|---|---|
| 1 | Determine current CO status via DOB NOW Public Portal | Search by address or BIN; review existing CO documents and any open jobs |
| 2 | Engage a licensed architect to review scope and determine filing type (ALT1, new building, LNO) | Architect will assess whether work requires an ALT1 or if LNO is the appropriate path |
| 3 | File required application via DOB NOW: Build (or submit LNO application to borough office) | LNO requires separate multi-step application process — not filed through DOB NOW |
| 4 | Complete plan review and address any objections from DOB plan examiner | Plan examination may be self-certified by approved PE/RA in some cases, speeding the process |
| 5 | Obtain required agency sign-offs (Fire Department, DOT, other agencies as applicable) | Assembly uses, eating/drinking establishments, and other use types have additional agency requirements |
| 6 | Pass final DOB inspection | Inspector confirms work matches approved plans; TCO may be issued if minor items remain |
| 7 | CO or amended CO issued by DOB; posted in the building | CO must be posted in a visible location in all multiple dwellings |
Frequently Asked Questions
What is a Certificate of Occupancy in NYC?
A Certificate of Occupancy is a document issued by the NYC Department of Buildings that legally authorizes occupancy of a building or portion of a building for a specific use. It certifies that the structure has been inspected and complies with applicable building, zoning, and safety codes for the designated occupancy type. It is required for all new construction and whenever use, exits, or occupancy of an existing building changes.
Do I need a CO to sell my property in NYC?
In practical terms, yes. While New York law does not explicitly prohibit selling a property without a CO in all circumstances, lenders will not fund a mortgage on a property without a proper CO (or applicable LNO exemption), and title companies will flag the issue. Buyers’ attorneys routinely require sellers to resolve CO issues before closing. A property with a CO that does not match its actual use — for example, a residential building with a commercial ground floor that was never reflected in an amended CO — will encounter serious obstacles at sale.
What is a Letter of No Objection in NYC?
A Letter of No Objection (LNO) is issued by the NYC Department of Buildings to confirm that a building constructed before 1938 is exempt from the CO requirement because its use, exits, and occupancy have not changed since construction. An LNO is not a CO — it is a written statement that no CO is required. Obtaining one involves a multi-step application process at the relevant borough office and typically takes 6 to 8 weeks. An LNO is commonly required by lenders and title companies as a substitute for a CO on qualifying pre-1938 properties.
What is a Temporary Certificate of Occupancy?
A Temporary CO (TCO) allows a building or portion of a building to be legally occupied while minor outstanding work items are completed. TCOs expire 90 days after issuance and must be renewed or converted to a final CO. Many NYC new development projects operate under a sequence of TCOs during phased construction. A TCO is better than no CO, but lenders and buyers typically expect a final CO or a clear timeline to obtain one before closing on a new construction unit.
My building was built before 1938 — do I need a CO?
Buildings constructed before 1938 were built before NYC’s first comprehensive Certificate of Occupancy law and are generally exempt from the CO requirement — provided the use, exits, and occupancy have not changed. If that is the case, you can apply for a Letter of No Objection from the DOB to confirm the exemption. However, if any subsequent alteration changed the building’s use, occupancy load, or exit configuration, the exemption no longer applies and a CO is required reflecting those changes. An architect or expediter can review your building’s history and advise on the correct path.
Need a Certificate of Occupancy, an amended CO, or a Letter of No Objection for your NYC property? All Boro Expediter manages the entire process — from initial DOB review through final issuance. Contact us to get started.
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