Passive solar heating uses building techniques to more efficiently heat and cool a house without mechanical or electrical systems.  Sustainable Architecture can be used to naturally moderate indoor air temperature by paying attention to the local site and climate.  A solarium is an example of passive solar heating.  A solarium works by using large south facing windows to heat up a thermal mass.  A thermal mass is usually a concrete floor or wall.  The mass will hold the heat and naturally release it to circulate the house as it cools at night.  A solar chimney can be used to improve natural ventilation in houses and buildings using convection air currents.  

If you are building a new house or doing significant remodeling you should consider consulting an architect who specializes in sustainable design.  Creating a tight shell for your house is a good place to start.  Insulated concrete forms (ICF) for walls will reduce lost heat.