How can an area simultaneously be part of two rooms?

[Alexonian]

First we have a defined room in Version X3.



Then we should have the remainder of the basement, excluding the small room. Right? However that small closet is a room unto itself and it is also part of the larger, open basement.




1.) How do I fix this problem so that when I click on the large open basement I get the exclusion of the small defined room?

2.) I've put a furred drywalled wall around the perimeter of the basement, but unlike rooms above where a wall pushed up against another wall will sense the blockage and stop, this doesn't work in the basement and this wall will not sense the presence of the concrete wall and will go right through it. This obviously means that the spacing between the walls is going to be determined by my best guess rather than by the program and secondly the interior measurements completely ignore the furred wall as though it didn't exist.

I've checked "double wall" and clicked the "furred wall option" on the interior wall, but it doesn't seem to be working. Can anyone give me a hand with this please?