So it turned out that my laundry room basically needed rebuilt. They should be able to brace the roof and just replace the two walls and floor (the other end of this "room" is a closet that was built correctly in the 20s). I got an estimate today for the room and, while there are some things I plan on vetoing (I can paint, etc, myself) I still feel like it's more expensive than I was expecting. Particularly since it won't be permitted.
I'm going to get a second estimate, but does anyone have any experience with this sort of thing?