i make windows, but i dont know anything at all about installing them in a house. my only suggestion would be to get triple glazed windows (3 panes of glass, 2 frames) and get either Shield or Gain as a LowE coating. LowE keeps the heat in in the winter and the heat out in the summer. Quite effective actually. well, that's my piece.
by the way, my company's website has a bit of info that might be able to help you out.
www.gienow.com
hope i helped a bit
