Open data
Housing stock of the Philadelphia region
The age of the housing in 637 towns and Philadelphia neighborhoods, which is the thing that decides what is under a carpet. Built by Deco Hardwood Floor from open Census data, published as CSV and JSON, free to reuse.
What is in the file
One row per town or Philadelphia neighborhood, with the age of its housing stock and the segments we derive from it.
| Indicator | Value | Source |
|---|---|---|
| Places covered | 637 | Census Gazetteer 2023 + City of Philadelphia |
| Housing units | 4,703,409 | ACS 2023 5-Year, B25001 |
| Built before 1978 | approximately 63.7% | ACS 2023 5-Year, B25034 (apportioned) |
| Places where 35% or more predates 1940 | 134 | ACS 2023 5-Year, B25034 |
How it was built
Municipal figures come straight from the Census. Neighborhood figures are aggregated from census tracts, because Philadelphia neighborhoods are not a Census geography.
Places come from the 2023 Census Gazetteer, filtered to a 50 mile radius of Philadelphia across Pennsylvania, New Jersey and Delaware. Housing figures come from the American Community Survey 2023 5-Year estimates. Philadelphia neighborhood boundaries come from the City of Philadelphia via OpenDataPhilly, and each census tract is assigned to the neighborhood its internal point falls inside.
Two numbers here are estimates, and they are labelled
The pre-1978 share is apportioned, and neighborhood medians are aggregated. Neither is a direct measurement.
The Census does not publish a 1978 cut, which is the line the EPA lead rule draws. The published band covers 1970 to 1979, and we assign 80 percent of it to the pre-1978 side, which is eight of its ten years. Every use of that figure on this site is written as "approximately".
The median year built is bottom-coded by the Census at 1939: the value means "1939 or earlier" rather than a real year. Rows in that condition carry median_year_is_bottom_coded, and no page on this site states a year for them.
Counts add across census tracts, so the share built before 1940 in a neighborhood is exact. Medians do not add, so neighborhood values for home value and income are unit-weighted averages of tract medians and are approximations.
Use it
The files are free to use with attribution, including commercially.
Released under CC BY 4.0. If you use it, a link back here is enough. We publish it because we already built it, and because a floor contractor arguing about the age of a housing stock should show the data rather than assert it.
Sources and references
- US Census Bureau, ACS 2023 5-Year. https://www2.census.gov/programs-surveys/acs/summary_file/2023/
- US Census Bureau, 2023 Gazetteer Files. https://www2.census.gov/geo/docs/maps-data/data/gazetteer/2023_Gazetteer/
- OpenDataPhilly, Philadelphia neighborhoods. https://opendataphilly.org/datasets/philadelphia-neighborhoods/
Send a photo and we will tell you what you are looking at
Wood floor work across the region starts with someone reading the house. We quote every job ourselves, with no salesperson in between, and a photo of the floor gets you a straight answer faster than a form does.
