First fire up UnrealEd/DukeEd
and make a large cube (subtract it). This cube will hold the terrain lofts. Also
make a second, large box out of the way for later use. The second box will NOT be used in
the level itself, it is just a temporary device.
Take note - regular room
you will build your lofts in, larger room will be used later when you are aligning
textures