You wouldn't leave your door wide open with the heat on high. Drafts can sneak through cracks and holes in your home or business' building envelope (the barrier between your indoor and outdoor environment) and waste 5-30 percent of household heating, according to the U.S. Department of Energy.

     You want a tight building envelope. Check for drafts around doors, windows, in attics and around the chimney. Visit http://www.energystar.gov/index.cfm?c=diy.diy_index for a DIY guide for sealing and insulating with Energy Star.

     Note -- The IRS will provide a tax credit (worth 30 percent of the cost of materials up to $1500) to homeowners who improve their home's building envelope in 2009-2010. Visit http://energytaxincentives.org/consumers/insulation_etc.php for more information.