The lower the U-value, the better the insulation. In colder climates, a U-value of 0.35 or below is recommended. These windows have at least double glazing and low-e coating.
Water heating typically accounts for 14 percent of your utility bill. Repairing leaky faucets, insulating the water heater tank and hot water pipes, and installing low-flow faucets and shower heads can result in significant additional savings.
By simply caulking, sealing, and weatherstripping around all your windows, outside doors, or where plumbing, ducting, and electrical wiring penetrate exterior walls, floors or ceilings, you can save 10 to 25 percent of your heating bill.
Look for dirty spots in your insulation, which often indicate holes where air leaks into and out of your house. You can seal the holes by stapling sheets of plastic over the holes and caulking the edges of the plastic.
To stop airflow between walls and floors, Install foam gaskets on all outlets and switches, and use child safety plugs backed with punch-outs to keep the cold air from coming through the sockets. Remember, be careful whenever working around electricity.
Attic doors are a major source of heat loss in many homes. To stop airflow, weatherstrip the edges and insulate the back side of the attic door. Fold-down stairs can be covered with a lightweight box made of rigid insulation.
Bathroom fan fixtures can poke into the attic insulation and create a pathway for air leaks. Caulk around them from below with high-temperature flexible caulk.
Small openings on the exterior of your home can allow for significant energy loss. Caulk around openings for electric, gas, oil and water supply lines, drainage pipes, plumbing for outside spigots, cable TV and telephone cables. Dryer vents, mechanical ventilation system vents and combustion air supply vents for furnaces should also be sealed.
Weatherstrip and caulk all cracks between the wall and the window trim, especially under the window sills. Replace broken glass and putty any loose window panes. Caulk around the moving parts of windows with a strip-away, non-permanent caulk during the winter. This type caulk can be removed easily in the spring.