Malachy writes from Cortlandt Manor, New York: "I recently read on your website that insulating the rafters of a home is not necessary if there is a insulated floor. What about the side walls. In my home the rafters and the side walls are not insulated. Should I insulate the side walls of the attic?"

Answer: There is no need to insulate the sidewalls of the attic if the attic space is not heated or air conditioned.

Insulation is needed to keep heat from moving from the warm side of a structure to a cold side. In a home, that means keeping heat in the living space during winter and out of the living space during summer. The insulation you have in the floor of the attic is doing just that - stopping the movement of heat between the attic and the living space below. Adding insulation to the walls and rafters would provide no additional benefit.

Ventilation is important in unfinished attics so be sure you have good air flow through the space. For information about how much ventilation is needed, check the Owens Corning Web site.