The building material has a special function.
Normally, you can create buildings from any surface (up to the user area limit) by using the buildingtool 'on the fly'.
With the building brush you can first paint and modify the plan, regardless of terrain form, painting across faces and surfaces.
Once you like to try out, how the plan looks in 3d
just select everything in skp,
and you can create all painted buildings with one click (and same settings) with a function on the toolbar.
After all buildings are created, it is very easy to modify their height / amount of floors with the buildingtool.
Painting building via building modifier also uses the building material.
If you want to change the plan, simply again select all elements and delete all buildings by pressing the button in the toolbar.
The buildings will be erased, and the faces under the buildings will be restored (horizontal).
Change now, what ever you like and create new buildings as decribed above.
Note:
As soon as you rename your buildings, it is better not to delete buildings anymore, since the names get lost with the deleted buildings.
