Andrew K has a project that should ring a bell with lots of homeowners: What's the best way of insulating a room over the garage so it becomes useful, conditioned space? Andrew lives in Massachusetts, in Climate Zone 5A, and would like to turn the space, what real estate agents used to call a "bonus room," into an office. The roof is framed with 2x8 rafters and already has both soffit and ridge vents, but no insulation whatsoever.