
Drapes or curtains — especially lined ones — help to insulate windows and stop drafts.
• Close drapes at night. In winter, as soon as the sun has gone down, pull your drapes to help keep the warm air in the room. If you don't, it will move outside by both conduction and radiation.
• Let the winter sunshine in. The sun's warmth is free and can help to heat up a room. So keep the drapes open during the day. (In summer, of course, do the opposite.)