Windows & Doors
Average windows comprise 15% of a homes surface area the costs are steep for replacing windows and the return on investment is often very low. That being said, windows are an important piece of your homes aesthetics and can often times have very visible air leaks. You do have options!
Weather Stripping
Weather stripping is the process of air sealing around windows.
Storm Windows
Placing Energy Star approved storm windows over existing windows can save equivalent amounts of money and energy during the winter as replacing your existing windows for a fraction of the cost.
Interesting Links
QuantaPanel - Low E Storm Windows
Larson - Low E Storm Windows
PNNL Lab -Evaluation of Low-E Storm Windows in the PNNL Lab Homes
Window Restoration
Companies can restore your old windows so they are both energy efficient and maintain the appearance of your home.
Treating Windows
Curtains and other window barriers can muffle convective currents near window, keep out the sun during the summer, and add to your homes décor!
Replacement Windows
Although converting from single pane windows to double pane could save money, make sure things like airsealing and insulation are done first. Unless, of course, your windows are in really bad shape (such as they are broken or you can see daylight between the frame and wall).
Interesting Links
Dept of Energy -Retrofit Techniques and Technology: Airsealing
Energy Star -Airsealing Info