The buildings also came from OSM. The OSM data contains height data [0] and where they don't have that information, I bet they assume some standard height that

The buildings also came from OSM. The OSM data contains height data [0] and where they don't have that information, I bet they assume some standard height that "looked right". [0] http://www.openstreetmap.org/browse/way/40758798 http://www.openstreetmap.org/browse/way/40758798 (the build:levels = 5 key/value)