Or, try adding in edge seals such as Velcro or magnetic strips. If you install covering on a north-facing window, you could save two to three percent of your home heating and cooling costs. Other window coverings can be effective energy savers, but only if they fit snugly on the windows. Even a vinyl shade can cut heat loss in half. More elaborate shades, such as quilted curtains, can cut those losses by 80 percent.
Venetian blinds are the least-effective energy savers because they have so many gaps.
Add an insulating lining to your draperies. Check your local drapery shop or fabric store. Better yet, install them outside to keep the wall and window shaded.