Blocks & Lots

What is a Building Identification Number?

A Building Identification Number (BIN) is a unique identifier for each NYC building.

The Department of City Planning assigns Building Identification Numbers, though the Department of Buildings may do so as well. The DOB uses BINs to track permits, codes, and violations.

Therefore, BINs are helpful for condo owners and buyers. They can help you identify a building in government databases.

One use for this is figuring out if there are violations on your property. This is important because building violations can lead to fines and penalties. Violations can also prevent you from refinancing or selling your home.

You’ll notice the BIN in the certificate of occupancy below. A CO is one of the 10 key documents in the life of a NYC building.

Check out Marketproof New Development for the most information anywhere on NYC condos.


You may be wondering how a BIN differs from a BBL, the identifier of your home’s borough, block, and lot. The Department of Finance issues the BBL, which it uses for tax purposes. By contrast, as we covered above, the DOB uses BINs.

BINs are more specific than BBLs. This is especially pertinent when it comes to co-ops because a single co-op may include several buildings and many units. All these units will share one BBL, or one block and lot. However, the buildings in the co-op will have different BINs.

Therefore, knowing a BIN can help you identify your co-op building in public records when knowing a BBL will not. But this is not the case for condos, for which each unit has a different lot number.

How to find Building Identification Numbers

The best place to find your Building Identification Number is on real estate data and analytics platform Marketproof. Marketproof classifies buildings at the individual BIN level, whereas many other property sites only go to the block-and-lot level.

Consider this Stuy Town building. The blue region covers the block and lot that contains this building. But the single building shaded purple is the actual building. Marketproof isolates this data so that you get a clearer view of properties you own or would like to consider buying.

Marketproof New Development is your premiere destination for information on new NYC condos and co-ops. It is powered by the most expansive and up-to-date data available anywhere on NYC condos.

Getting started with Marketproof

With Marketproof New Development, you can easily search both publicly listed properties and unlisted off-market properties not available on popular listing sites. Marketproof can increase the inventory you see by 9-10x what you may see on other sites. Create an account today, and get a 7-day free trial.

Marketproof New Development

Top photo courtesy of 215 Chrystie St.