How to check a building's violations before you rent

In most large US cities, a building's violation history is public record. Before you sign a lease, you can usually find out whether the building has open housing code violations, how long they have been open, and whether the landlord has a pattern of letting problems sit. This guide explains what records exist, how to read them, what to ask, and where Blueprint can pull the record for you automatically.

What city records actually exist

Coverage and terminology vary by city, but most US housing agencies publish some combination of these records as open data:

• Housing or building code violations. Issued when an inspector finds a condition that breaks the local housing code: no heat, a broken smoke detector, pests, structural issues, illegal occupancy and more. Cities usually grade these by severity.
• Complaints. A tenant-reported issue, which may or may not turn into a formal violation after inspection. New York City's 311 complaints are the best known example.
• Enforcement and litigation. Fines, hearings and, in serious or repeated cases, a housing court case against the owner.
• Evictions. Court-filed and, in some records, executed eviction history for the address, not the people involved.
• Certificates of occupancy and rental registration. Whether the unit is legally permitted to be rented out at all.

No single record tells the whole story. A building can have a messy complaint history but no real violations, or a quiet 311 log but a serious unresolved Class C violation. Read a few records together before you draw a conclusion.

Open versus closed violations, and why it matters

An open violation means the condition has not yet been certified as fixed. A closed violation means the owner either corrected it and the city confirmed that, or it was dismissed on appeal. The gap between the two matters a lot:

• A building with many closed violations and few open ones usually means problems get fixed, even if slowly.
• A building with violations that stay open for months, especially anything marked hazardous or immediately hazardous, is a real signal to slow down.
• Check the dates. A violation issued five years ago and closed a month later reads very differently from one open for two years.
• Watch for repeat violations of the same type at the same address. That often means a recurring problem, not a one-off.

Most cities also assign a severity class to each violation (commonly something like "hazardous," "immediately hazardous," or a lettered class). Treat the most severe open class as the one that matters most, not the raw count.

How to pull the record yourself

Every city publishes this data a little differently, but the pattern is the same: find the city's housing or code enforcement agency, then search by address.

• New York City: HPD Online lets you search any address for open and closed housing violations, plus complaints. The underlying data is also published on the NYC Open Data portal.
• Montgomery County, MD: the county's Housing Code Violations dataset is searchable by address.
• Elsewhere, search "[city name] code enforcement" or "[city name] open data" and look for a housing, building, or code violations dataset. Most mid-size and large cities publish one.

If a city has no public violations dataset at all, that is useful information on its own: you will need to ask the landlord directly, or call the local code enforcement office and ask whether the address has any history.

What to ask the landlord

Bring the record with you, and ask specifically:

• "I saw an open violation for [issue] filed on [date]. Has that been fixed, and is there paperwork showing it was?"
• "Has this unit specifically, not just the building, ever had a violation or a tenant complaint?"
• "Is there an active rental registration or certificate of occupancy for this unit?"
• "Has the building been in housing court for conditions, and is anything currently open?"

A landlord who answers specifically and can point to paperwork is a good sign. Vague reassurance with no documentation is worth following up on before you sign.

Honest coverage: where this works, and where it does not

Blueprint's full A to F building grade, built from a city's own violation and complaint records, is only available in 56 US cities and Montgomery County, MD today. Outside those places, Blueprint still shows a nationwide hazard and neighborhood layer for any US address, such as flood, wildfire and earthquake risk, but it cannot grade the building itself, because Blueprint does not yet have a supported building-record feed for that city. Even inside the covered cities, records can be incomplete or delayed at the source. A clean record is a good sign, not a guarantee. See data sources for the exact feed behind every city.

How Blueprint helps

Typing an address into Blueprint pulls these same official records directly, weighs each one by severity, and turns them into a single A to F grade, weighted by building size where the city publishes unit counts, so a 100 unit building is not punished simply for being large. Where unit counts are not published, the grade falls back to a total-based threshold and is flagged as approximate. You can see every underlying record the grade is built from, not just the letter. The grade is Blueprint's own calculation from public records, not an official city rating, and it does not replace reading the records yourself or asking the landlord the questions above. For how the grade is calculated, see how we calculate grades.

Sources

• NYC HPD Online, violations and complaints by address
• NYC Open Data, the underlying housing datasets
• Montgomery County, MD Housing Code Violations
• HUD, tenant rights
• See Blueprint's full data sources list for every city covered.

Related guides:

• Checking flood risk before you buy
• What a UK EPC rating means before you buy or rent