NYC Illegal Apartment & Conversion Help
Is there an illegal apartment in the home you just bought?
A converted basement, an attic unit, a house split into extra apartments — and now a violation. You did not build it. We walk you through legalizing or correcting it, every step.
How it usually goes
It rarely arrives at a convenient time
This is the sequence most NYC homeowners go through. If any of it sounds like your week, you are in the right place.
- It surfaces
A 311 complaint, a title search, or a DOB inspection turns up more units than the building is approved for.
- It is real
An open DOB violation for an illegal conversion — space or units that were never legalized.
- And it is yours
The DOB enforces against the current owner — no matter who did the conversion or when.
- The turn
One call — we read the file and give you the deadlines, the options, and the order to act.
What comes next
You will not be guessing your way through this
From the first consultation, you will understand the violation, the deadlines, and the path to legalizing or correcting the unit.
What counts as a conversion
An illegal conversion takes more than one form
If a prior owner created living space the city never signed off on, it can surface as any of these — and each follows a process with a deadline.
A basement or cellar apartment
A below-grade unit the Certificate of Occupancy never permitted.
An attic apartment
Living space carved out of an attic or top floor without DOB sign-off.
One unit too many
A one- or two-family quietly turned into one more apartment than is legal.
A subdivided floor
Rooms partitioned into separate rentable units without approval.
Use that does not match the CofO
More dwelling units, or a different use, than the Certificate of Occupancy on file.
Conversion work without permits
Egress, plumbing, or partition work a prior owner never filed.
You may not have created the conversion — but as the current owner, you may still have to deal with it.
That is the hard truth of NYC enforcement, and it is also why getting the response right matters. We explain the hearing, the correction deadlines, whether the unit can be legalized, and any tenant issues — so you are working from a plan instead of guessing.
Here is how we work it
An illegal conversion follows a process — not a dead end
Knowing the four steps ahead of time is the difference between panic and a plan.
Review the violation
We pull the DOB and OATH records and the Certificate of Occupancy, and confirm exactly what is open and what it demands.
First
Identify the deadlines
Correction periods and hearing dates are the deadlines that cost the most when missed. We calendar every one.
Right away
Legalize or correct
Some conversions can be legalized through DOB filings; others must be returned to the approved use. We tell you which path your property is on.
Before the hearing
Resolve it
We file the paperwork, appear at OATH where needed, and pursue the close-out the facts support.
Through to close
Want the detail? Read our full DOB violation guide.
Why homeowners call us
We do this every week
NYC buildings law is what we do
DOB and OATH violations across all five boroughs — not a side practice.
Certificates of Correction
We prepare and file the DOB paperwork that closes violations — routinely.
We move on your timeline
Missed deadlines cost the most. We help you act before the hearing, not after.
Straight answers
Questions homeowners ask us first
You did not create this problem. You do not have to solve it alone.
A free 15-minute case review tells you exactly where you stand — the deadline, your options, and what to send us. Picking up the phone is the easiest part.
Attorney Advertising. Prior results do not guarantee a similar outcome. The information on this page is general and not legal advice; contacting Nacmias Law Firm does not create an attorney-client relationship.