I have seen shells built around mobile homes, fifth-wheels, etc.
They don't tear out the original structure and it looks horribly lame.
There is a single-wide for sale right now that has a real roof on 4x4 posts, which I have seen a few times. I just think it is weird when the new roof is the same size as the mobile home itself. Why does it need to be so big?
This one is at least a double-wide roof, so yay. Covered patio.
It looks weird, though!
https://www.zillow.com/homedetails/4.../8409177_zpid/