Roof details have long been a thorn in the side for energy-conscious builders. Providing high insulation levels, adequate ventilation, and a continuous vapor barrier is a real challenge. Among the builders I interviewed for this article I found a wide variety of solutions to these goals, but also some similarities. Insulated Ceilings Insulated ceilings (unheated attics) are not as common as insulated roofs (cathedral ceilings) among the builders and designers I spoke with – most of whom are primarily involved with custom homes. Al Topping, a builder in Merrimack, N.H., and Chuck Silver, an architectural designer in New Paltz, N.Y., use a very similar system in which the ceiling joists are boxed off with a rim joist, and the rafters are