Illegal Conversion Violation with Unpermitted Plumbing in NYC
A Class 1 (Immediately Hazardous) violation for altering a building to create additional dwelling units without DOB permits — almost always involving unpermitted plumbing that must be legalized or removed.
What It Means
An illegal conversion is an alteration of an existing building to create additional apartment units without the required DOB permits or approval — a basement turned into an apartment, a two-family carved into three. DOB classifies illegal conversions as Class 1 (Immediately Hazardous), and the summons typically requires you to either legalize the space or restore the premises to their prior legal condition. Because conversions add kitchens and bathrooms, unpermitted plumbing and gas work is nearly always part of the condition.
Why You Got It
Common triggers: 311 complaints from neighbors or tenants, inspections following other violations, and conversions discovered during sales or refinancing. Prior-owner conversions become the current owner’s violation.
Consequences & Penalties
Class 1 illegal-conversion summonses are subject to additional daily penalties of $1,000 per day, imposed by OATH, which continue to accrue until the summons is certified as corrected — up to a maximum allowable penalty of $45,000. That is on top of the OATH penalty for the underlying violation, and Class 1 conditions must be corrected immediately.
Information current as of 2026-07-11. Penalty amounts and deadlines change — confirm specifics against your violation notice or with a Licensed Master Plumber.
How to Clear It
- Decide the path with a design professional: legalization (where zoning and code allow) or restoration to the prior legal condition.
- To stop the daily penalties, submit an acceptable Certificate of Correction within 45 days of the Notice of Violation date and before the hearing date, whichever comes first.
- For legalization: a PE or RA files the application, and a Licensed Master Plumber files permits for and performs the plumbing and gas work to current code.
- For restoration: remove the added fixtures and cap the plumbing under permit, with licensed sign-off.
- File the Certificate of Correction through DOB NOW: Safety with proof of the corrective work (the old AEU2/AEU20 paper forms are no longer used).
- Attend the OATH hearing with the approved correction documentation to resolve the summons.
Timeline
Class 1 conditions must be corrected immediately. Daily penalties accrue until correction is certified; an acceptable Certificate of Correction within 45 days of the Notice of Violation (and before the hearing) stops the per-day accrual.
Related Laws & Rules
- NYC Admin Code §26-126(1)(e)(1)
- NYC Construction Codes
- Multiple Dwelling Law
Frequently Asked Questions
How much are illegal conversion penalties in NYC?
Class 1 illegal-conversion summonses carry additional daily penalties of $1,000 per day, imposed by OATH, accruing until the summons is certified as corrected — up to a maximum of $45,000, on top of the standard penalty for the underlying violation.
How do I stop the $1,000-per-day penalty?
Submit an acceptable Certificate of Correction up to 45 days from the date the Notice of Violation was issued and before the hearing date, whichever occurs first. If approved, present the approval letter at the hearing as proof of correction.
Should I legalize the conversion or restore the space?
It depends on zoning and code. Where legalization is possible, a PE or RA files the application and a Licensed Master Plumber legalizes the plumbing under permit. Where it is not, the space must be restored to its prior legal condition — fixtures removed and lines capped under permit.
The conversion was done by a prior owner. Am I still responsible?
Yes. Open violations attach to the property, and prior-owner conversions become the current owner’s obligation to correct — a common discovery during sales and refinancing.
Sources
Clear This Violation With a Licensed Master Plumber
Send us your notice and we'll handle the full NYC DOB plumbing violation removal — from diagnosis through DOB sign-off. Same-day response.