Looking again click on window dim get width and add a block that has 2 attributes width and your entry of height. Place this block inside room, copy etc as required. In dwg there are 3 in 1 room.
Ok you can get theses blocks inside room using a SSGET "WP" within polygon using lisp so could get a list of these blocks that are bounded by yellow line in your dwg, then pick room area.
Look at that all done.
So we can help you 1st step is make a block on a dummy no plot layer. Search for a lisp, get dimension value and also insert block with attributes using lisp.
Hint (command "-insert" blockname (getpoint "\nPick point") 1 1 0 att1 att2)
Repost dwg with block