©2015 Green Building Advisor. From The Taunton Press, Inc., publisher of Fine Homebuilding Magazine.
Ignoring all other things, from a pure energy efficiency perspective, is it more energy efficient to insulate the slopes or the floor of an attic? Assume in both cases a vented attic (even if insulating slopes, there is fiberglass down below that needs to be vented. If insulating slopes, would you also endeavor to plug up holes in the floor, or is that unnecessary once attic is brought within house envelope?