Energy conservation and reducing heat loss in buildings is a very powerful way to lower energy costs. Sometimes great savings can be realized with simple measures. This subject provides a great vehicle for teaching science content that is very relevant to everyone's daily life--and financial well-being. In this article, the author first discusses three simple rules that will help with understanding how to save energy: (1) Heat always moves from a region of higher temperature to one of lower temperature; (2) Hot air rises; and (3) Heat loss from a building depends greatly on the outside surface area of a structure. He then suggests classroom activities that will involve and encourage students to develop ideas on how to reduce home energy use.