We've had a look at this and found that it seems to work. What I did was:
- Download the building footprint data from here in SHP format
- Unzip the zip file on my computer, which produced files BUILDINGS.dbf, BUILDINGS.prj, BUILDINGS.shp and BUILDINGS.shx (and others for EASEMENTS and PARCELS) but I have ignored those
- Made a new THERMOS map using GIS data; in this I selected all the BUILDINGS related shapefile stuff. You need to select these all together when uploading the GIS, as they are related and all necessary.
You can see the resulting map here.
Things I can imagine might have tripped you up would be:
- Uploading the zipfile, rather than unzipping it and getting out the buildings
- Not including all the parts of the shapefile when you uploaded the GIS data (in particular the shp, dbf and prj parts are all necessary)
Hope this helps