In the winter the biggest source of heat loss in most houses is the windows. Now matter how good your windows are, they are still made of glass with only a thin layer of air to act as insulation. Even if you have triple-paned gas with exotic gases in between the panes, you are still losing most of your heat through your windows.

So an easy way to save energy in the winter and make your house warmer is to reduce the amount of heat loss through your windows. And an easy way to do this is by getting some drapes, curtains, or insulating blinds. This can be a cheap way to reduce the energy loss through your windows by a significant amount resulting in a warmer house, lower energy bills, and less use of natural resources.