Hazards by Building Age
A building's construction era is one of the strongest predictors of which NYC home-safety hazards apply to it. Pre-1960 buildings carry a legal lead-paint presumption under Local Law 1; the roughly 54% of NYC's housing stock built before 1947 has had the most time for roofing, plumbing, and structural systems to age, raising mold and pest risk. Newer construction avoids the lead presumption but not mold, pest, or fire-safety rules.
Informational only — not legal, medical, or engineering advice.
NYC Construction Eras and Their Legal Hazard Triggers
NYC law does not treat all housing the same — several major hazard rules are keyed directly to a building's year built. The table below lines up the construction-era brackets against the specific legal thresholds that apply, based on NYC Local Law 1 of 2004, Local Law 55 of 2018, and Local Law 7 of 2004.
| Era | Legal / structural relevance |
|---|---|
| Before 1960 (multiple dwellings, 3+ units) | Legally presumed to contain lead-based paint under Local Law 1 of 2004. Owners must investigate units with children under 6 annually and remediate hazards; peeling lead paint in a child-occupied unit is a Class C (immediately hazardous) violation. |
| 1960–1978 | No automatic Local Law 1 presumption, but owners who know lead-based paint is present in a 3+ unit building still carry investigation and remediation duties. Federal lead-paint ban (1978) had not yet taken effect for any of this bracket. |
| 1978–present | Outside the federal residential lead-paint ban; not covered by the Local Law 1 presumption. Still fully subject to Local Law 55 (mold), NYC Housing Maintenance Code pest obligations, and Local Law 7 (carbon monoxide detectors) — none of which are age-limited. |
| All eras (age-independent rules) | Local Law 55 of 2018 (mold), NYC Admin Code § 27-2018 (pests), and Local Law 7 of 2004 (CO detectors near fuel-burning appliances) apply regardless of construction year. |
Source: Local Law 1 of 2004 (bill text via National Center for Healthy Housing); Local Law 55 of 2018 and Local Law 7 of 2004 per Mold & Lead and Fire & CO references on this site.
How Much of NYC Housing Is Actually Old?
NYC's housing stock skews older than most major US cities. According to NYC Housing and Vacancy Survey (NYCHVS) data compiled by the Citizens Housing & Planning Council (CHPC), roughly 54% of the city's housing units — about 2 million — were built before 1947, and more than 80% of all NYC housing is over 50 years old. That means most NYC residents live in buildings whose plumbing, roofing, and electrical systems long predate current code, whether or not the building falls under the Local Law 1 lead-paint presumption.
54%
of NYC housing units built before 1947
80%+
of NYC housing is more than 50 years old
17%
of pre-war units self-report 3+ housing problems in NYCHVS
This is why age-linked hazards — lead paint, aging plumbing that feeds mold growth, and structural gaps that give pests harborage — are not a niche concern in NYC housing; they describe the physical condition the majority of the city's residents actually live in.
Source: CHPC — NYC Housing Stock Visualization, built on NYCHVS data. Pulled 2026-07-04.
Checking Your Own Building's Record
Building age is a starting point, not a verdict — the most reliable signal for any specific NYC address is its actual violation and complaint history, both of which are public.
HPD Housing Maintenance Code Violations
NYC's official violations dataset (NYC Open Data, dataset id wvxf-dwi5)
records every Housing Maintenance Code violation issued against a building, with a severity class —
A (non-hazardous), B (hazardous), C (immediately hazardous), or I (information order) — plus
inspection date, correction status, and the building's BIN/BBL identifiers. Search by address at HPD Online
or query the raw dataset directly on NYC Open Data.
311 Service Requests
Every 311 housing complaint — heat, hot water, pests, mold, structural — since 2020 is logged in
NYC's "311 Service Requests from 2020 to Present" dataset (dataset id erm2-nwe9).
Filing a 311 complaint is also what triggers an HPD inspection in the first place. File at portal.311.nyc.gov
or by phone.
What this page does not claim
We have not run a statistical join between building year-built and violation rates — that would require matching the HPD violations dataset against PLUTO year-built records, which is beyond an informational reference page. Treat the era table above as the legal-obligation map, and use HPD Online or NYC Open Data for the actual condition of any specific address.
Frequently Asked Questions
Does my building's age tell me what hazards to worry about?
Broadly yes. NYC ties specific legal obligations to construction-era cutoffs — pre-1960 buildings carry a legal presumption of lead paint under Local Law 1, and older buildings generally have had more decades for roofing, plumbing, and structural systems to degrade, which raises moisture and pest-harborage risk. But age is a risk indicator, not a diagnosis — always confirm actual conditions via inspection or your building's violation history.
What year cutoff does NYC use for the lead-paint presumption?
Local Law 1 of 2004 presumes lead-based paint is present in any multiple dwelling (3 or more residential units) built before 1960. Owners of buildings built 1960–1978 have conditional obligations if they know lead-based paint is present. The presumption can be rebutted only with certified inspector or risk-assessor testing submitted to NYC HPD.
How much of NYC's housing stock is old enough to be affected?
Roughly 54% of NYC's housing units were built before 1947, and more than 80% are over 50 years old, according to NYC Housing and Vacancy Survey data compiled by the Citizens Housing & Planning Council (CHPC). That is the majority of the city's housing stock carrying pre-war-era building systems.
Do newer buildings have zero hazard risk?
No. Newer construction is not subject to the Local Law 1 lead-paint presumption, but it is not exempt from mold, pest, fire, or carbon monoxide rules — Local Law 55 (mold), the NYC Housing Maintenance Code (pests), and Local Law 7 (carbon monoxide detectors) apply city-wide regardless of a building's age.
How do I check my own building's violation history?
Search your address at HPD Online (hpdonline.nyc.gov) for open and closed Housing Maintenance Code violations, or query the underlying dataset directly on NYC Open Data (dataset id wvxf-dwi5), which records violation class (A, B, C, or I), inspection dates, and correction status for every HPD-inspected building in the city.
What's the difference between a Class A, B, C, and I violation?
NYC HPD's Housing Maintenance Code Violations dataset classifies every violation as Class A (non-hazardous), Class B (hazardous), Class C (immediately hazardous), or Class I (an information order, not a hazard finding). Peeling lead paint in a unit with a child under six is specifically defined as a Class C violation under Local Law 1.
Where do I report a hazard tied to my building's age?
File through NYC 311 (portal.311.nyc.gov or call 311) for HPD inspection of any housing condition — lead paint, mold, pests, heat, or structural issues. 311 requests are recorded in the city's "311 Service Requests from 2020 to Present" dataset (id erm2-nwe9). In a fire or gas/CO emergency, always call 911 first.