We have all heard about solar energy as the alternate source of energy for a very long time. The first thing that comes to mind when talking of solar energy in building use is seeing solar panels mounted on roof tops of large buildings and even some residences. There is no thought of conserving energy, just an alternate source. But, today, we are going to talk of passive solar energy which takes advantage of the site, climate and materials to consider for solar energy to minimize energy use. There is no point in changing the source of our energy from electric or gas or oil to solar and being lavish in using the energy by giving no thought to the site, materials or other elements. It defeats the purpose of conserving energy and being green.

Energy.gov government website gives details on how to design a home with passive solar energy, complete with details on how and where to place the building, the direction in which you will get the most unobstructed solar heat, thus keeping your home or building comfortable all through the year and reducing heating and cooling costs to almost half the typical cost of cooling and heating.
Detailed instructions and information on passive solar energy can be obtained here