Building footprint
The outline of a building as seen from directly above — a polygon on a map, with no height information. The basic unit of every open buildings dataset.
Footprints are what satellites and volunteers can actually produce at scale; everything else (height, use, condition) has to be measured separately or estimated.
{# Definition → argument. Same word-boundary match that places the inline hover in the reader, so this list is exactly where the term is explained on the page. #}
Where it comes up
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