Insulation and Air Infiltration
The single most important step in residential energy conservation is the installation of thermal insulation. To make sure your home is properly insulated, follow these tips:

• Check current insulation levels, and properly insulate a new or existing home.
• Insulate ceilings, walls, and floors over unconditioned crawl spaces.
• Find the obvious places where air can sneak into your home, then make repairs to plug the leaks by caulking, weather stripping, and using plastic covers.
• Check some of the other major air leakage areas, including: air ducts; window sashes and frames; plumbing utilities and wall penetrations; furnace flues; fireplaces; attic entrances; wall outlets; and recessed light fixtures.
• Make sure your fireplace has tightly fitting dampers that can be closed when the fireplace is not in use.

To make your windows and doors more energy efficient, follow these tips:

• Double-glazed windows (two panes of glass separated by a sealed air space) cut heat transfer by 40-50 percent. In extremely cold regions, triple glazing could be economically justified.
• Single-glazed windows should have storm windows. A wood or metal frame storm window provides a second thickness of glass and a layer of still air that reduces heat transmission markedly.
• Install storm doors at all entrances of the house.
• Weather strip and caulk around all entrance doors and windows to limit air leaks that could account for 15-30 percent of heating and cooling energy requirements.
• Keep the overhead door of an attached garage closed to block cold winds from infiltrating the connecting door between the house and garage.