I am converting a large attic into living space. There will be approx. 800 sq ft. The house was built in 1927 and I live in MN. The house has a new roof. I will be finishing the interior, but do not know much about insulation. Should I use blown in, or the rolled stuff? What "R" factor should I use, and should it be faced or unfaced? before I "build" the ceiling, how much room should I leave between the insulation and the roof/ceiling for air flow? What about the exterior walls. I have a contractor adding a 14' dormer on one side, and a 12' dormer on the other. Thanks in advance for your postings!