Posted by Jim Locker on January 16, 2001 at 07:55:48:
I would not try to raise the house. From what you describe, the room in question is probably an add-on (maybe in a former incarnation it was a porch) and the foundation was not quite adequate to take the weight of the walls and roof.
Study the walls and roof where they join the main structure. Are there any cracks, or signs that they are pulling apart? How about the siding? Is it parallel to the ground, or running downhill?
How far is this back room above the dirt? Can you get access to the floor joists? If so, what kind of shape are the joist ends (where they meet the foundation) in? Rotting perhaps?
You need to answer these questions. Once you do, your choices will be more obvious.