Hollow gable roof and also other hollow roofs and the possibility to add windows onto roofs. Its a whole puzzle when i try to get that and it costs lots of bucks and time to get it done. I would just love a window view up the sky instead of a low ceiling. Theres no room for natural lighting. Also, the posibillity to size up walls and stuff. I would love a wall which can adjust to hollow roofs so it has a corner and stuff and also, adding a wallpaper onto the walls would be nice, so you can just put in your decal and call it a day instead of trying to with paintings (also ignore my englis**** isnt my first language).