What HomeNHealthy reports
City profiles use Census American Community Survey tables B25034 and B25035 to show median year built, the share of housing units built before 1980 and the share built before 1940.
Why pre-1980?
The federal residential lead-paint ban makes 1978 an important threshold, but the ACS publishes 1970–1979 as a single decade bin. A precise pre-1978 percentage cannot be observed from that table. HomeNHealthy reports the defensible pre-1980 figure and explains why it is close to—but not identical to—the lead-paint threshold.
Housing age is context, not condition
An older home may be carefully renovated and maintained. A newer home may have moisture, ventilation or material problems. Age can help identify questions worth asking, but it does not prove the presence of lead, asbestos, radon, mold or any defect.
About ACS estimates
The ACS five-year dataset combines survey responses collected over a multi-year period. Values are estimates and have margins of error. HomeNHealthy uses exact Census place matches and withholds the field when a reliable match is unavailable.
Property-level next steps
Use the city statistic as a prompt to check the actual year of construction, renovation history and condition of the home. For potential lead hazards, follow EPA/HUD guidance and use qualified testing or risk-assessment professionals.