Even with the door closed tight, winter drafts can enter a room to make you shiver and force your furnace to work extra hard to maintain a comfortable temperature.
According a various expert sources, drafts can account for anywhere from 5 percent to 30 percent of your home's energy consumption. That's wasted energy and wasted money.
The easiest way to stop drafts and save energy is to place a rolled towel at the base of the door where the draft is coming through. This will stop cold air from flowing into the room and reduce the amount of energy you need to stay warm.
If you're handy with a needle and you want a classier solution than an old towel can offer, you can make your own draft snake. Just choose an attractive fabric, sew it into a long tube, stuff it with some material that offers good insulation, sew the end closed, and put it at the base of the door in place of that towel you've been using.