Therefore, proper insulation contributes a lot to indoor comfort while consuming very little energy. Generally, a house that is not well insulated will let heat out during winter and cool air during summer, which in turn makes heating and cooling systems work extra hard to elevate high energy bills with bad environmental impacts.

Insulation of attics, walls, floors, and basements to drastically reduce energy use for comfortable internal temperatures. Of these, attic insulation can be among the cost-effective improvements to be made since heat rises, and a poorly insulated attic alone may account for as much as 25% of heating energy loss.