Where to insulate a house?

Houses come in infinitude of shapes and sizes, but all of them incorporate some of the elements of the dwelling at right. The overall rule in insulating a house is simple: insulation should be present at any surface separating living spaces form unheated areas, since that is where heat loss occurs – and also where the sun’s heat can make unwelcome entry in the summer. All exterior walls should be insulated, not neglecting any wall of a split-level house that rises above an adjacent roof. Any wall between a heated room and unheated area such as a garage, utility room or open porch also demands insulation, as do floors separating living spaces from such unheated areas. And do not overlook the overhanging portion of a room cantilevered out from the rest of the house.

If the house has unheated cellar or crawl space, the floors above must be insulated. In the case of a finished basement, the below-ground walls require insulation. Similarly, the floor of an unheated attic calls for insulation, whereas finished room in a heated attic must have an insulated ceiling and knee walls as well as production for the ceilings and walls of all dormers.