How To Make a Complaint to 311

Step 1: Look up the Address

Please note: We recommend looking up this information about an address before making a complaint, since it can provide useful context about the building.

1. Go to

2. In the left sidebar at the bottom, under Buildings Information, type in the house number, street name and select the borough. Click Find.

3. You will now see a page that contains the public records of the building. You can view the number and types of complaints made against the address, if any have been made. You can also view all past and present job filings on the address.

Step 2: Contact 311 about an -Illegal Conversion-

Go to:

(This is the official website of NYC – 311 City of New York)

  1. Go to: > Make a complaint
  2. Get help with: > Select Construction from the dropdown
  3. Specficially: > Select Illegal Conversion from the dropdown
  4. A description will appear in the area on the right side. Scroll down, and you will see a number of items to select from. Choose: Report illegal conversion or alteration of: Residential Building

Construction for an illegal conversion is usually excessive and out-of-character. These are some items that you might be able to use in your complaint, if it applies.

  • Work contrary to plans
  • Change in egress: closed side entrance. Only one entrance at front of building.
  • Excavation of basement
  • Debris/soil removed from basement
  • Rear and side windows closed up
  • Interior completely gutted and many small rooms created.
  • No permits for construction work


Please note that you will need to make separate complaints about different items, e.g. “excavation of basement” or “removal of front yard” There is a character limit so it will need to be short.

You can also attach up to 3 pictures with your complaint.

Have you already identified a building? Click the button below to make a complaint about an illegal residential conversion.

Make a Complaint (Residential)


For a full list of complaint types and their codes, you can download the Department of Buildings complaint code sheet here.

**** Do not use the Code Number in your complaint. ****