Sites that offer energy saving tips for window coverings. In an effort to reduce energy costs at the window you might find that insulated curtains do a better job than most blinds. Except for cellular blinds which offer an R-value of between 2.5 to 5, curtains offer greater savings. Part of this is due to the tight weave, the vinyl backing, and also because curtains tend to have air pockets within the folds of fabric. http://www.dantehill.com/drapery-panels/images/prepared-drapery-panels.jpg Adding a sheer or voile at the window increases dead air between the window and the curtain, plus the cold then travels down the sheer to the floor instead of directly from the cold pane of glass into the room. Yes. I know sheers are not as popular as they once were in the fashion world, but there are beautiful and modern designs that will give you both privacy during the day and added insulation during the dark nights. http://www.woodyattcurtains.com/articles/wp-content/upl