I'd like to put gable roofs up instead of repairing the old flat roofs on each side of the existing gable roof. (see picture). the new gable roofs would face outwards with the side of the house instead of the front like existing gable. Is this a feasable idea that I could have this done by just having the contractor build trusses and sit right on top of existing flat roof? Any Idea what the cost would be compared to having new rubber roof installed on the flat roofs? Would really prefer gables. Thanks, (this is in Edmond Ok.) if anyone knows a good framer that is reasonably priced in that area. or Oklahoma City.