Adding a room to a manufactured home

[Dana Maman]

Hey,

Looking to buy a property together with my in-laws in AZ (close to Prescott area), so to allow us to get into the market this way. Wanted to add value to the property eventually with another unit but first looking at large lots (with the right zoning for all of this) with a manufactured home that needs a little rehab. I was thinking of adding a room as one way of adding value. 

I was wondering if anyone has any experience with adding a room to a manufacture home, cost, how it went, things to look out for, was a regular contractor ok?

looking forward to some answers.