Windows contribute more than twice as much to the cooling bill as the next biggest part of the home's load - the air ducts, and nearly three times as much as the walls and roof combined.

The opportunity exists to cut the window driven cooling load in half simply by installing high performance windows with low solar heat gain lowE glass.

The example shown here is for a new home with insulated walls and roof, and typical of most new homes - with little or no roof overhangs to shade the windows.

The high performance window reduces solar heat gain dramatically for windows in the sun, and also provides greater insulating ability for when windows are shaded, or at night, and in the winter.