Actually, this is on the first floor of a rented house. I am unsure of the outer wall construction. All I know is that the walls are pretty thick (maybe 8-10 inches) of unknown consruction. The inside wall have a stucco-like texture (inside maybe plaster(. I am reluctant to blindly cut into the wall to cut a hole to the outside. I don't live there nor own the place. It is just for a friend. Oh well, maybe I will go after the wall with the recip. saw. Thanks for your help, guys.