Renters · Guide

How to check a NYC building before you sign: violations, complaints and red flags.

The city publishes a building's record for free. Here are the four official tools, what each one shows, and the red flags worth walking away over.

Gabe Einhorn, co-founder of NessooPublished Oct 17, 2026

3 min read

The short answerNessoo Report · nessoo.com

Before you sign a NYC lease, search the address on HPD Online for housing violations and complaints, the Department of Buildings' BIS and DOB NOW for building complaints and the Certificate of Occupancy, and ACRIS for who owns it. All four are free city tools.

→HPD violations are ranked A (non-hazardous), B (hazardous) and C (immediately hazardous).
→The Certificate of Occupancy states a building's legal use.
→ACRIS shows deeds and recorded documents for Manhattan, Queens, the Bronx and Brooklyn.

You would never buy a used car without checking its history.

But people sign a 12-month lease every day without looking up the building.

In New York, you don’t have to guess. The city keeps a public record on almost every building, and it is free to search.

Here are the tools I would tell any friend to check before signing. It takes about ten minutes.

1. HPD Online: housing violations and complaints

HPD is the city’s Department of Housing Preservation and Development. It enforces the housing maintenance code, the rules about heat, repairs, pests, leaks and safety inside apartments.

Search the address on HPD Online. Depending on the building, you can see:

Complaints and violations. What tenants reported, and what inspectors confirmed.
Property registration. Who the owner and managing agent are.
Charges and litigation. Tied to the building.
Vacate orders. When the city ordered people out of a building or unit.

Violations come in three classes:

Class A, non-hazardous. The owner has 90 days to correct it.
Class B, hazardous. 30 days.
Class C, immediately hazardous. Most must be fixed within 24 hours. Heat and hot water get no grace period at all. Lead paint, window guards, mold, mice, roaches and rats get 21 days.

A few Class A violations in a big building is normal. A long list of open Class C violations is not.

2. DOB: complaints, permits and the Certificate of Occupancy

HPD covers what happens inside your apartment. The Department of Buildings covers the building itself.

The city points renters to two DOB tools:

Building Information System (BIS). Search by address to see complaints, violations, actions, applications and inspections. It also shows the Certificate of Occupancy.
DOB NOW Public Portal. Applications filed in DOB NOW, compliance filings for boilers, elevators and facades, and violations for owners who failed to file boiler or elevator inspection reports.

The one to read closely is the Certificate of Occupancy. It states the legal use of the building.

Here is why it matters. If the certificate says two families and you count five doorbells, ask questions before you send any money.

3. 311: where problems get reported

311 is how New Yorkers report problems to the city, online, in the app or by phone.

When a tenant reports something like no heat, HPD can contact the owner, send an inspector and issue a violation. Those complaints and violations are what you then see on HPD Online.

Two ways to use it:

Before you sign. A building with a history of heat complaints every winter is telling you something.
After you move in. Talk to your landlord first. If that doesn’t work, file with 311. Heat complaints can even be filed anonymously.

4. ACRIS: who actually owns the building

ACRIS is the Department of Finance’s property records system. It lets you search records and view document images for Manhattan, Queens, the Bronx and Brooklyn from 1966 to today.

You can find deeds and other recorded documents, and the building’s borough, block and lot number.

Why a renter should care:

Make sure the person is real. If someone says they own the place, see whether the name lines up with the deed or with the owner on the HPD registration.
See recent sales. If the building just changed hands, ask who manages it now and who handles repairs.

Red flags worth walking away over

Open Class C violations. Especially heat, hot water, lead paint or pests.
A vacate order. On the building or the unit you are seeing.
No valid registration. Owners of buildings with 3+ units must register with HPD every year, with a September 1 deadline. If it is missing, ask why.
A Certificate of Occupancy that doesn’t match. More units than the building is legally allowed.
A name that matches nothing. The person collecting your deposit isn’t the owner, the managing agent, or anyone they work with.
No bedbug report. Owners must file an annual bedbug report with HPD and either give it to tenants with each new lease and renewal or post it in the building. Ask for it.

The bottom line

A listing is the landlord’s story about the building.

The city’s records are the building’s story about the landlord.

Read both. Then decide. If you want the whole renting process laid out, here it is, step by step, and here is how to read the lease once you get one.

“Ten minutes of searching beats a year of regret.”
Gabe Einhorn, co-founder of Nessoo

Frequently asked questions

How do I check a NYC building for violations?

Search the address on HPD Online for housing maintenance complaints and violations, and on the Department of Buildings' Building Information System (BIS) for building complaints and violations. Both are free.

What do HPD violation classes A, B and C mean?

Class A is non-hazardous, Class B is hazardous and Class C is immediately hazardous. Heat and hot water violations are Class C. Most Class C violations must be corrected within 24 hours.

How do I find out who owns a building in NYC?

Search the address on ACRIS, the city's property records system, to see deeds and other recorded documents. HPD Online also shows a building's registration, which owners of most rental buildings must file every year.

Can I find out if a NYC apartment building has had bedbugs?

Owners must file an annual bedbug report with HPD and either give tenants a copy of the filing with a new lease or renewal, or post it in the building. Ask for it before you sign.

Cite this

Einhorn, Gabe. “How to check a NYC building before you sign: violations, complaints and red flags.” Nessoo Report, Nessoo (nessoo.com), Oct 17, 2026.

About Gabe Einhorn

Co-founder of Nessoo, the verify-first rental marketplace in New York. He writes every Nessoo Report. nessoo.com

Sources