I don't see that there needs to be clearance around the building walls and especially paths when sculpting terrain. For instance, I was laying a path and it came to a bit of terrain that was too uneven and it refused to be laid. So I pushed down the terrain and built the rest of the path. Then I wanted to raise the terrain back up to at least the height of the path, so that the path would appear to have been laid on the ground as normal. But the terrain insisted on leaving a gap under the path. Is this really necessary?