As flat ceilings go the way of the dinosaur, vaults and tall walls intersecting with attic spaces are becoming the norm. Designers, builders, framers and insulators have to start thinking about what an attic space really is: UNCONDITIONED SPACE! Whatever the R-value of the wall insulation is on the outside walls, the same holds true for walls intersecting with attic space.
Remember, for ENERGY STAR BOP points, the lowest R-value is what we use. R20 + R5 means R20 + R5 everywhere!
