Diagram illustrating Passive Solar Gain using the Sun and Architectural Design for a Sustainable HomeUtilizing the sun can go a long way to freely and efficiently heating your home during the daylight hours. A building that is intentionally sited to Face the Southern Exposure taking into account the arc of the sun and the maximum exposure of daylight hours will enjoy Free Heating. Passive Solar is a beautiful thing. The direct heat or light of the sun can be captured and utilized. Here are some designs that need only be placed in the direct line of the sun to get the job done.