There are noticable cracks inside. The drywall for the ceiling has a 1/4" to 1/2" crack that runs completely the full length of the addition. The addition in the bedroom has wall to wall carpet and is only noticeable when you step on the seam where the new floor meets the old. It seems as though there could be a 3/4" gap. What if the house is out +/- 1" or greater? What expense will I be looking at if a professional has to do the work. Are we talking about raising the entire house and replacing the foundation?