there is already a bedroom and a bathroom upstairs adjacent to this attic space. no stairs will be needed. just a door cut and a floor put down. then the dormer neeeds put in becasue it is A frame. the A frame is sitting on a wide roof space that comes out quit a ways so the dormer would sit perfectly on the back of the house. there is already electricity. all of the floor boards will support a room. i have been reading about this and most are saying 50-100,000. i just couldnt believe that. The whole house we are buying for 80,000 at a very good deal becasue it is worth quit a bit more. but i could not see a dormer costing that much becasue even to build a whole room with foundation, electricity, walls, plans, etc...cost 30,000 at the minimum.