In New York City the Certificate of Occupancy is the legal record of a building's use and unit count. If a house is marketed as a two-family but the C of O says one-family, most lenders will not finance it as a two-family — which is why Jortevsky Real Estate Firm verifies the C of O against the physical building before any South East Queens multi-family goes to market or receives an offer.
It happens in the same order almost every time. A buyer finds a two-family in Springfield Gardens or St. Albans, runs the numbers with the second unit's rent carrying part of the mortgage, gets an accepted offer, signs a contract, and then hears from the lender four weeks later that the building is a legal one-family. The financing that was underwritten on two units does not exist. The deal either restructures on much worse terms or dies.
What a Certificate of Occupancy actually is
The Certificate of Occupancy, issued by the New York City Department of Buildings, states the legal use of a building and how many dwelling units it may lawfully contain. It is the controlling record. Not the listing, not the tax bill, not the fact that there have been two families living there since 1994, and not the seller's assurance that everybody on the block did the same thing.
Buildings constructed before 1938 may not have a C of O at all. In that case the Department of Buildings can issue a Letter of No Objection, which serves a similar evidentiary purpose. Either way, there is a document, and someone should read it before money moves.
Why lenders care so much
A lender underwriting a two-family purchase will often count a portion of the documented rental income from the legal second unit toward the borrower's qualifying income. That is frequently what makes the purchase possible at all. If the second unit is not legal, the income cannot be counted, the loan-to-value calculation changes, and the appraisal itself may come back describing a different property than the one under contract.
How to check before you offer
- Pull the Certificate of Occupancy for the address through DOB NOW or the Buildings Information System. Note the stated occupancy and the number of dwelling units.
- Walk the building and count what is physically there: separate entrances, separate kitchens, separate utility meters.
- If the two counts differ, stop and get an explanation in writing before going further.
- Check the DOB permit and violation history for the address. Open permits and unresolved violations are separate problems that will also surface at the lender.
- Ask specifically about basement and attic spaces. A finished basement with a kitchen is the single most common source of an unlawful third unit in South East Queens.
If you are selling
Resolve this before the listing goes live, not during a contract. A seller who discovers the discrepancy at week five of a contract has lost their best buyer and restarted their marketing period from a weaker position — the listing now carries days on market and a story attached to it. A seller who discovers it before launch has options: legalise the unit where feasible, market the property accurately as a one-family with a rentable configuration, or price it correctly for what it legally is.
None of those options is as good as a clean C of O. All of them are better than finding out in contract.