NYC Surcharge Explorer
An interactive map of every property on NYC's tax roll, modeling exposure to a proposed non-primary-residence surcharge — which parcels cross the threshold, their market value, and who owns them.
A full-screen map of all ~923,000 properties on the NYC assessment roll, colored by exposure to a proposed non-primary-residence surcharge. Red parcels sit over the surcharge threshold; blue ones are on the roll but under it. Search by address, owner, or 10-digit BBL and click any parcel for detail.
Features
Surcharge-exposure, market-value, cap-distortion, ownership, and watch-list layers; live roll-wide stats (parcels over threshold, annual surcharge base, co-op units ≥ $1M, homes within $1M of the line); parcel-level drill-down; and owner and BBL search.
Tech Stack
MapLibre GL with Protomaps vector tiles over OpenStreetMap and NYC Department of Finance roll data, plus ACRIS deed records for ownership. Built as a Vite single-page app.