Insulation is used to keep air of different temperatures on each side of a boundary and minimize the heat flow from the warmer substance to the cooler substance. Weather proofing is eliminating the cracks and creases that air can flow through such as on the edges of front/back doors and windows. Both good insulation and weather proofing can be used together to reduce utility bills and keep the temperature within the home more stable.

Insulation is found inside walls and in the attic of ceiling. It is made of materials that do not conduct heat well. This helps prevent the outside air from influencing the inside of the home as much. In the process of weather proofing, an analysis is done to see where in the home there are inefficiencies in keeping the outdoor air from influencing the inside of the home. Examples of weather proofing include adding more energy efficient windows, sealing creases and cracks on the edges of doors and windows, adding screen door, sealing leaks that may be present in attic or basement, and energy efficient roofing.

The advantages to having good insulation and weather proofing include lower utility bills, more uniform temperature distribution in the home, less bugs and dust entering the home, and better control of the air in the home. When inspecting a home or buying a home it is important to examine how well the home is insulated and weatherproofed.