Check a Building is an NYC property research service that brings public building records together in one place. Users can search by address to explore current information on violations, permits, facade filing deadlines, ownership, legal use, sales, liens, and other records sourced from NYC Open Data, DOB NOW, ACRIS, and New York State public records. The service is designed to help renters assess building conditions and landlord records, support buyers researching properties, and give prospective tenants information to review before signing a lease.

With a free account, users can save buildings, receive alerts, and download reports; the platform also offers branded PDF reports drawing on its listed sources. Check a Building publishes practical guides and glossary definitions explaining topics such as housing violations, rent stabilization, heat and hot water rights, landlord ownership, and borough-block-lot identifiers. Its site notes that its scores are estimates, not official city ratings or credit scores, and that the information is not legal or financial advice or for tenant screening or decisions about individuals