Energy Saving Windows and Doors

Houses leak most of their heat through the windows. Seals and weather-stripping on cheap and badly installed windows allow heat-robbing drafts, and regular glass is not a very good insulator. But the initial cost of quality energy-efficient windows can give one pause. Is it really worth the extra money to get windows that can reduce your house's energy consumption by as much as twenty-five percent?

The United States' Federal Government thinks so, and is offering homeowners a tax credit of ten percent of energy-saving windows' purchase price (up to $500 per year). This is a tax credit, not a deduction. So, if you purchase and install a $1000 patio door that is "Energy Star" rated or has a Manufacturer's Certification Statement, you can reduce your tax bill for the year by $100, and your patio door's effective cost is only $900. This tax credit is known as the "Existing Home Tax Credit for Fenestration", and is good for windows installed between December 31, 2005 and January 1, 2008.

The National Fenestration Rating Council (NFRC) rates windows' energy-saving capabilities. They use two measures to rate windows: the U-factor shows how well the window keeps heat in your house (the lower this number, the better); and the Solar Heat Gain Coefficient shows how well the window keeps your house cool (again, the lower the better). You will need to save the NFRC stickers that come with your windows, along with your purchase receipt, in order to qualify for the tax credit. Any other pertinent documentation can only help.

What should you look for in a window, besides an Energy Star rating? The market supplies many choices, but here are some guidelines.

First, most insulating windows are made with two, or sometimes three, panes of glass. The manufacturer often fills the space between the panes with an insulating inert gas such as argon or krypton.

Next, window manufacturers can achieve lower U-Ratings by glazing the glass to various degrees with a special film or a reflective metallic coating. Some glazing even reduces transmission of damaging ultra-violet rays. In addition to insulating your house, this kind of glazing can protect your furniture and drapes from deteriorating due to UV exposure. If installing a West window, try to get glass with the lowest Solar Heat Gain Coefficient possible --- rooms with West exposure are notorious for overheating in the afternoon, and this type of window will help.

Finally, good windows have a tight seal that you should be able to feel when you open and close it in the showroom. Try it out. Repeatedly. Compare the cheap windows to the more expensive ones. With practice, you should be able to tell a well sealed window from a badly sealed one. Only the seal on your refrigerator door should be better.

Look at your heating and cooling bills, and take off ten percent. Price out your windows, and take ten percent off the price of the energy-efficient ones. Now, can you afford not replace your drafty old non-insulating windows?