Methodology & Data Sources

Data Sources

We read from NYC Open Data, the City's public data platform (powered by Socrata). The records below are published by City agencies on their own schedules. We do not edit them — we consolidate and explain them.

• HPD

  Housing Preservation & Development (HPD)

  Tracks housing maintenance code violations: heat and hot water failures, mold, lead paint, pests, and other habitability conditions.

  HPD violations on NYC Open Data(opens in a new tab)
• DOB

  Department of Buildings (DOB)

  Tracks construction permits, facade and elevator inspections, and stop-work orders issued by the City.

  DOB violations on NYC Open Data(opens in a new tab)
• 311

  NYC311

  Records non-emergency complaints and service requests reported by residents and tenants, including heat, noise, and water issues.

  311 service requests on NYC Open Data(opens in a new tab)

Explore NYC Open Data(opens in a new tab)

Risk & Building Health

Every building page shows a risk badge — low, medium, or high — and three health metrics. The badge is a quick signal, not a verdict.

• Low risk

  Few or no serious open violations on record.

• Moderate risk

  Some open violations or complaints that may need attention.

• High risk

  Multiple serious open violations, including hazardous conditions.

Building health metrics

• HPD open violations

  Open violations from HPD, broken down by class: Class C (immediately hazardous), Class B (hazardous), and Class A (non-hazardous).

• DOB open violations & active permits

  Open violations and construction permits from the Department of Buildings.

• 311 complaints (last 12 months)

  Non-emergency complaints reported to NYC311 in the past year.

The risk level is produced by our data engine from these records. We do not publish a numeric formula, and the badge is guidance only — always check the official records for your building.

Privacy & Architecture

Your browser never talks to third-party data APIs directly. Every request goes through our own server endpoints — a pattern called a backend-for-frontend (BFF). We validate each response against a strict schema before it reaches your screen, so malformed or unexpected data is caught on our side. We do not collect personal information about you, and you do not need an account to use this site.

Legal

• Data is provided by the City of New York and other public sources and is served 'as is'. We do not guarantee that it is accurate, complete, or up to date.
• NYC Building Check is an independent project. It is not affiliated with, endorsed by, or operated by the City of New York or any of its agencies.
• The information on this site is general and is not legal advice. For advice about your situation, consult a qualified attorney or contact the relevant agency.
• Always verify important information with the official source before acting on it.

This page explains our data sources and methodology for general information only. It is not legal advice, and it is not a substitute for the official records.