I joined the county's 2020 lidar building footprints (LARIAC) to the assessor roll, so every one of the 1,129,558 buildings inside the City of LA has a footprint, a height, and a year built for 98% of them. (All public info, but kind of a pain to grab.)

The page extrudes them in 3D and plays the city filling in from 1880 to now. Colors are by decade, or switch to height and fly to downtown. Hover any building for its address, year, height, and footprint. Some things I found: the 1950s, not the 1920s, is the biggest decade still standing; the Valley visibly snaps into existence after the war; and downtown's 150-foot height limit shows up as a hard ceiling until 1957. Zoomed out it draws a 100 m grid because a citywide view can't carry a million polygons, and heights are exaggerated below street level zoom (the corner label says by how much).

Stack: DuckDB spatial for the join, tippecanoe to PMTiles, MapLibre fill-extrusion, all static files on R2 with no server. City of LA only, since the parcel polygons I pulled stop at the city line.

Happy to answer questions about the data or the rendering.

[Just a fun project, no commercial relevance.]

Didn't realize you could zoom in until I saw this. It looks really cool when you zoom in and it replaces the boxes with actual building shapes.