Buildings put up before 1940 average 0.49 Housing Maintenance Code violations per apartment over the last 12 months. Everything built since averages 0.14 to 0.16. That is roughly a threefold gap, and it holds across all five boroughs. It is also an average, not a rule: 40.9% of pre-war buildings picked up no violations at all in that year, so the era tells you what to expect before you look, and the address tells you what is actually there.
How We Measured It
Building age shapes what a renter can check before signing, so we measured it against the housing code record rather than against reputation. Two public datasets carry everything needed: every violation HPD issued in the last 12 months, and every residential tax lot in the city with its year built and apartment count.
Data Sources and Date Window
Violation counts come from HPD's Housing Maintenance Code Violations dataset, filtered to violations inspected between September 22, 2025 and September 22, 2026. Year built and residential unit counts come from the Department of City Planning's MapPLUTO dataset, limited to lots with three or more apartments. We matched the two on borough, block and lot, which covers 172,169 residential lots holding 2.8 million apartments. Those lots account for 858,151 of the 931,775 violations HPD issued citywide in the window.
The Four Construction Eras
We split the stock into four eras: before 1940, 1940 to 1973, 1974 to 1999, and 2000 onward. Before 1940 is the conventional line for pre-war housing. The 1973 cutoff matters because rent stabilization generally covers buildings of six or more units built before 1974, so the split separates most regulated stock from the rest. The 1974 to 1999 group is the first generation built entirely under the 1968 building code, and 2000 onward isolates the newest construction.
What Counts as a Violation
We counted every violation issued in the window, open or already closed, since a violation closed last month still describes a problem the building had this year. We also counted Class C violations separately. Class C covers immediately hazardous conditions, and the class letter sets the repair deadline, so a building's mix of classes says more than its raw total.
Violations Per Unit by Construction Era
Pre-war buildings carry both the highest total and the highest rate. They hold 46% of the apartments in the dataset and take 74% of the violations. The three newer eras land within two hundredths of each other on violations per apartment, so the meaningful line in this data is 1940, not 1974 or 2000.
| Construction era | Buildings | Apartments | Violations in 12 months | Per apartment | Class C per apartment | Share with none |
|---|---|---|---|---|---|---|
| Before 1940 | 118,243 | 1,304,513 | 634,936 | 0.49 | 0.15 | 40.9% |
| 1940 to 1973 | 22,111 | 805,375 | 111,860 | 0.14 | 0.05 | 67.1% |
| 1974 to 1999 | 9,931 | 217,616 | 30,406 | 0.14 | 0.03 | 51.3% |
| 2000 and later | 21,884 | 521,914 | 80,949 | 0.16 | 0.04 | 44.5% |
Class C Violations by Era
The hazardous end of the scale follows the same shape. Pre-war buildings average 0.15 Class C violations per apartment a year, three to five times the newer eras. Class C is the category that covers no heat, no hot water, rodents, and lead paint hazards, which is why the gap matters more than the headline number: a pre-war building is not just collecting more paperwork, it is collecting more of the violations that make an apartment hard to live in.
The Zero-Violation Share Tells a Different Story
Read the last column against the rest and the neat age ranking breaks down. Buildings from 1940 to 1973 are the most likely to have a completely clean year at 67.1%, while buildings from 2000 onward manage it only 44.5% of the time, worse than the 1974 to 1999 group. Size explains most of that: newer buildings average 24 apartments against 11 in the pre-war stock, and the more apartments a building has, the more likely at least one tenant reported something. A clean record is easier to hold in a small building, which is why zero violations is not automatically the best sign when you compare two addresses.
Why the Era Gap Exists
Age alone does not explain the gap. A building from 1925 and one from 2015 differ in construction date, and they are also maintained under different rulebooks today.
The Code a Building Was Built Under
New York City enacted its first dedicated Existing Building Code on January 17, 2026, a separate code governing how existing buildings are altered and maintained. Until it takes effect, that work continues under the Administrative Code and the 2022 Construction Codes, and owners can still choose to renovate prior-code buildings under the 1968 Building Code. New construction has no such option. A building permitted today has to meet current codes from its first inspection.
What the New Existing Building Code Changes
The Existing Building Code becomes effective July 17, 2027 under Local Law 42 of 2026. Once it does, the 1968 Building Code option for prior-code buildings goes away, and alteration work on older stock moves to a single set of rules instead of a patchwork tied to construction year. That shift has not happened yet, so the older stock's maintenance rules remain in transition.
Limits of This Analysis
The era gap is real in this data, but it does not prove that age causes worse conditions. Three limits are worth knowing before you lean on it.
Rent-Stabilized Buildings Skew the Older Stock
Rent stabilization generally covers buildings of six or more units built before 1974, with smaller categories for pre-1947 buildings occupied since mid-1971 and newer buildings that took certain tax benefits. Because regulated units cluster in the pre-1974 stock, the older-era numbers partly reflect a regulatory category rather than construction age by itself. The date thresholds for rent stabilization run along the same era lines that split this table.
Complaint-Driven Inspections Create Reporting Bias
Most HPD inspections start with a tenant complaint rather than a routine sweep. A building with tenants who call 311 generates more inspections, and therefore more recorded violations, than an equally imperfect building where nobody reports anything. A low count can mean a well-run building or a quiet one.
What This Data Cannot Tell You
These are citywide averages by era, not a verdict on any address. A well-managed pre-war building beats a poorly managed new one regularly, and 40.9% of pre-war buildings had a clean year. Treat the era as a starting expectation and the building's own record as the answer.
How to Use This When Comparing Two Apartments
If you are weighing a pre-war unit against a newer one, run both addresses through the same check instead of assuming the newer building wins on age. Comparing two buildings on their public records means normalizing by apartment count, the same way the table above does, and weighing open Class C conditions ahead of old closed paperwork. Search either address in the building lookup to pull its violations, complaints, registration and legal actions in one place, then see whether it follows its era's pattern or breaks from it.
Frequently Asked Questions
Do Pre-War Buildings Really Have More Violations?
Yes, on average. Buildings from before 1940 average 0.49 HPD violations per apartment a year against 0.14 to 0.16 for later construction, based on violations issued between September 2025 and September 2026 matched to city lot records. The gap holds for hazardous Class C violations too, at 0.15 per apartment against 0.03 to 0.05.
What Does Pre-War Mean for an NYC Apartment?
Pre-war describes a building constructed before the United States entered World War II, generally before 1940. It refers to construction era, not condition. Many pre-war buildings have been fully renovated, and 40.9% of them recorded no violations at all in the last 12 months.
Is New Construction Always the Safer Bet?
Not automatically. New buildings average fewer violations per apartment, but they are also larger, and only 44.5% of buildings from 2000 onward had a clean year against 67.1% of buildings from 1940 to 1973. New construction also carries its own issues, including facade and mechanical problems that show up in Department of Buildings records rather than HPD ones.
Which Violations Should Worry Me Most?
Open Class C violations. They cover immediately hazardous conditions such as no heat, no hot water, rodents and lead paint hazards, and they carry the shortest repair deadlines. A handful of closed Class A violations from three years ago says far less about a building than one open Class C from last month.
What Code Governs an Older NYC Building Today?
Existing buildings are currently regulated under the Administrative Code and the 2022 NYC Construction Codes, with an option for owners to alter prior-code buildings under the 1968 Building Code. New York's first dedicated Existing Building Code takes effect July 17, 2027 and replaces that patchwork with one set of rules for existing buildings.
Why Are Rent-Stabilized Apartments Usually in Older Buildings?
Rent stabilization generally covers buildings with six or more units built before 1974, plus smaller categories for older buildings occupied since mid-1971 and newer buildings that accepted certain tax benefits. That threshold, rather than the physical age of the building, is why regulated units cluster in the older stock.
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