Solar energy is free, renewable and non-polluting, so why isn't it used everywhere today? Most people have the same implementation questions: Do you have to change your lifestyle with a passive solar system? Are there concerns with its variability and is it worthwhile? Are you better off going with a traditional heating system? Solar-based living does not necessarily mean a house full of glass and complicated electronics. There are some simple guidelines that will enable your home to enjoy the sun's energy to the fullest.

House Orientation

It is not obvious to most people how to orientate their house properly to take advantage of freely-available solar energy. Most homeowners, much less city planners, are careless in positioning their house correctly to absorb as much sunlight as possible during winter and be shaded in summer. Work it out like this:

• Locate magnetic south with a compass at your desired site. Confirm true north and south which are the solar points. Place the home at right angles with the long axis.
• Position deciduous trees along this path to shade the house from the summer sun. As the autumn leaves fall, the winter sun will still warm your home. 
• Planting cedars, pines and other evergreens in the north or east makes a good wind- and storm-break. Alternatives include hills, rock outcroppings and neighboring homes.

Insulate, Insulate, Insulate

An under-insulated home which is prone to air leaks will reduce options for comfort, energy efficiency and low cost. The bottom line is that less cost is incurred in conserving energy than in acquiring more (free) energy to heat a substandard home. An area with high air conditioning loads in summer needs extra radiant barrier insulation in the top section of the house. 

Window Design

Windows are a passive solar collector. A vertical glass window can capture low winter rays and avoid high summer rays. This is how you can design a contemporary home with maximum solar efficiency:

• Position most of the needed glazing along the house’s south side or long axis.
• Choose the best affordable, quality windows. Triple-glazed glass that is Krypton-gas filled proves most efficient and lowers energy loss during the night.
• Note that low-E glass windows are not suitable as solar collectors, especially on the south side.
• Windows facing possible winds (and their opposite side) should open for a smooth cross-flow of night air to cool the home.
• Restrict glazing on north-facing walls.
• Do not glaze the south windows excessively. Too many windows also mean a lot of heat. 

Finishing Touches 

The following finishing touches are meant to make your home's energy efficiency "just right": 

• Ensure that your home is properly ventilated with an air-to-air heat exchanger. 
• Make shade available for all but north-facing windows so that the summer sun will not heat up the house. 
• Consider sun-screen blinds during the summer.
• Living space should have a thermal absorber as well as a buffer system to prevent the sun overheating a well-insulated home. Using solar mass like tiles or cement flooring and walls in dark colors absorbs the heat and moderates internal temperature. In