README
Philadelphia Housing and Land Use
Ten collections describing property, zoning, vacancy, and affordable housing in Philadelphia, mirrored from the City of Philadelphia's ArcGIS services via OpenDataPhilly. Together they answer what exists on a parcel, what the zoning code permits there, whether the city believes it is empty, and what publicly funded housing has been built.
Property parcels, land use, and building footprints cover the whole city. Zoning base districts and overlays record what the code allows, and a lookup table decodes every zoning code. The city's vacancy model flags likely-vacant lots and likely-vacant buildings. Affordable housing production lists DHCD-funded projects completed since 1994 and the units each one delivered. The council districts give each location its political representation.
Each collection ships as GeoParquet in CRS84 (longitude, latitude), with PMTiles for rendering and two to three verified map styles. Start at the catalog AGENTS.md for join keys, worked queries, and the data quirks that cause most wrong answers.
Collections
📁 10 collections (click to expand)
Affordable Housing Production
Affordable housing projects funded by the Division of Housing and Community Development and completed since 1994. DHCD funds developers to build and maintain affordable units across the city.
City Council Districts (2024)
Coverage
The collections cover the City of Philadelphia. Each collection.json gives its exact bounding box.
Source
Processing Notes
Extracted from City of Philadelphia ArcGIS FeatureServer endpoints on 2026-08-26 using portolan extract arcgis, one service per collection. Every layer is served from the city's ArcGIS Online organization fLeGjb7u4uXqeF9q. Feature counts were checked against each service's returnCountOnly response, and all ten collections match their source exactly.
The services serve EPSG:3857 (Web Mercator). The GeoParquet is reprojected to CRS84 (longitude, latitude) for all collections, so ST_Area(geometry) returns square degrees; reproject to EPSG:2272 to measure. The Shape__Area and Shape__Length columns keep the publisher's Web Mercator metres.
Column meanings come from three sources. ArcGIS field aliases supplied attested names such as basereg = "Base Registry Number". The PASDA metadata record supplied the building footprint FCODE key, which states "1810 = Building 1830 = Tank". The city data team's post on the OpenDataPhilly forum supplied the vacancy rank semantics. Land use category labels were derived from the data; see AGENTS.md for the query.
zoning_descriptions is a non-spatial lookup table. portolan extract arcgis reports "0/0 layers" for services that advertise a table rather than a layer, so that parquet was written with DuckDB from the same FeatureServer query endpoint. See portolan-cli#812.
The 2026-08-26 extract reordered land use with gpio sort hilbert to give its row groups spatial locality.
Updates and versions
A scheduled job checks every source daily. It re-extracts a collection only when the city edited its rows, and it records a new version only when the rows changed. Each refresh repeats the processing above and sorts every spatial collection with gpio sort hilbert. The current data is always at <collection>/<collection>.parquet. Each earlier version stays at <collection>/versions/<version>.parquet and never changes. Each collection.json lists every version with its dates and checksum. The first version of every collection is the 2026-08-26 extract.
The publisher states an update cadence for three collections on OpenDataPhilly. A version is recorded at most once per interval below.
Each collection carries updated (the newest version), phl:source_updated (when the city last edited those rows), and phl:update_frequency.
Citation
City of Philadelphia (2026). Philadelphia Housing and Land Use. Retrieved from OpenDataPhilly. Mirrored on Source Cooperative at https://source.coop/nlebovits/phl-housing-demo.
Attribution
City of Philadelphia
License
Contact
Nissim Lebovits nissim.lebovits@radiant.earth
Generated by Portolan from STAC metadata and .portolan/metadata.yaml