My MIL has a single storey house with a footprint of about 40x40. I'd like to talk to some contractors in her area about pulling off the roof and replacing with another half-storey using room-in-attic trusses.
The house was originally build with a 40w x 25d footprint. The previous owner added a 40w x 15d addition on the back. However, the roof on the addition is nearly flat, and, well, as I am sure you can imagine, it has performed less than ideally over the years.
If interested, please send me an email at jimhausch (at) gmail (dot) com