According to the US Department of Energy (DOE), about one-third of the heat loss in a typical home happens through doors and windows, with doors alone accounting for approximately 11 percent of home air leakage. Older doors—along with those that have not been properly installed or air-sealed—are particularly vulnerable to air leakage and uncontrolled heat transfer. Most experts agree that caulking and weatherstripping a home to prevent air leakage will usually pay for itself in energy bill savings within a year, and the Rocky Mountain Institute estimates that weatherizing a typical home's windows and doors will reduce its annual CO2 emissions by between 400 and 600 pounds.
- door sweep: A type of weatherstripping used to seal the bottoms of doors against infiltration and heat loss.
- U-factor: A measurement of a how effectively a door or window protects against heat loss; the lower the U-factor, the better a door insulates.
- weatherstripping: A material applied to the gaps around windows and doors in order to seal them against air leakage.
- National Fenestration Rating Council
- EERE Consumer's Guide - Weatherstripping
- EERE Consumer's Guide - Caulking
- Weatherization Assistance Program for low-income families
- Energy Information Administration - Energy Efficiency
- Keep Warm Illinois - Doors
- EERE Consumer's Guide - Exterior Doors
- EERE Consumer's Guide - Caulking & Weatherstripping
- RMI's Cool Citizens - Everyday Solutions to Climate Change
- Urban Options - Weatherization Guide
- RMI Home Energy Briefs - Building Envelope
- EERE Consumer's Guide - Glossary of Energy-Related Terms