[Dave L]

We looked into this, we had a 1950's brink bungalo with a block foundation. We talked to a company that specifically does second floor additions that are mainly prefab and they had done a few homes in our area. We didnt go too far down the road but essentially they remove the roof and span the entire structure with laminated joists then hoist the prefab sections up and close it in. The process from removing the roof to closing it in is 1 week. The inside can be contracted out or you can do it yourself. The foundation didnt seem to phase them in the least but I am sure further into the process they would have to have an engineer do an inspection.