National Per-Address Year-Built Database for Lead-Based-Paint Risk Screening (United States, 41 States + DC)

Year-built records for 53,128,426 individual U.S. homes, assembled from public county and state assessor parcel records across 41 states plus the District of Columbia. Each row is one address with its documented construction year and the lead-paint era that year falls into (pre-1940, 1940-1979, 1980 and later). Residential lead paint was banned in the United States in 1978, and construction era is the strongest single public predictor of whether lead paint is present. The database supports address-resolution screening for lead-based-paint risk. Files: one gzipped CSV per jurisdiction (42 files; columns id, state, fips, county, parcel_id, address, year_built, lead_era, source), the public assessor or parcel source behind every state's records (sources_manifest.csv), machine-readable per-state row counts for integrity checking (counts.json), and the harvest orchestrator plus the full source registry (harvest_code_and_registry.zip), sufficient to re-harvest the database from the same public services. Coverage follows what county and state governments publish. Louisiana, Kentucky, Mississippi, Kansas, Vermont, and Maine publish no usable statewide year-built records; Nassau County, NY is paywalled; Suffolk County, NY is partial; San Diego County, CA is excluded in this version because its source publishes two-digit year codes (disclosed with all exclusions in counts.json and the README). All records were harvested in June 2026 from about 125 public ArcGIS, Socrata, and CKAN services operated by county and state governments. Records are public government data; this compilation is released under CC-BY-4.0. This dataset stores the documented year built for each address; it does not assert the presence of lead in any specific home. Supports: Ritter (2026), GeoHealth 2026GH002053 (in press), and a companion parcel-resolution manuscript in preparation.