there exist areas in the USA, where literally no buildings show up in the OSM data.
Fortunately Microsoft published building footprints for the whole contry.
Microsoft's files by state are way too large for most systems to process.
I did find some data splitted by US Census tract boundaries. These files can be handled by most GIS software. See the different colors representing census tract areas.
Merging them with OSM data reveals the dramatic increase of buildings.
OSM with US building footprints:
There is some overlay and even some inaccuracy of the buildings.
But for our purpose the inaccuracy is negligible.
I assume, best way is to remove all OSM buildings and keep the Microsoft buildings.
But next, we have to mass modify the attributes of these buildings.
Currently I work on the whole process manually, but it would be a significant improvement to find a good workflow.
What do you think about it?