Upgrade for Old Windows. Instead of replacing a sound single-pane window, consider adding Solar Gard Silver AG 50 Low-E Window Film. During the winter months, AG 50 reflects 63 percent of interior heat back into a room, the maker claims. And during the summer, it prevents solar heat gain and blocks 99 percent of UVA and UVB rays. It’s available clear or in a variety of tints. Installed costs range from $6 to $14 per square foot. Bekaert Specialty Films, 877/273-4364, solargard.com
