You can (most likely!) thank the OSM project for the building footprint and height data (along with pretty much all the street data in this map).

I've recently been playing with shademap.app and it's pretty incredible for planning a solar panel install. Google Earth has always been able to show you shadows for any given time of day, but only for natural features (mountains, hills, generally the shape of the earth), but doesn't take into account buildings. Shademap is using OSM building data to calculate buildings as well.