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Replacement Windows

For a typical house, windows can account for 10% to 30% of the heating and cooling bill.

replacement windows

Upgrading from single-pane windows to "superwindows" can cut this in half or better, so savings of up to 15% of your current bill are reasonable. Depending on where you live, this can amount to $50 to $100 per year. Spread over 20 years, this means $1,000 to $2,000. You can get a better estimate by running our Home Energy Adviser.

But the big thing to keep in mind is that many of these window replacement firms use simple double-pane windows; for just a little more money up front, you can save a lot of energy over the long haul by asking for windows with special low-e coatings and inert gases, such as argon or krypton, which fill the space between the panes of glass. Some manufacturers even offer "superwindows" with one or two thin plastic films sandwiched between the panes of glass. These windows can reduce energy loss to one-half as much energy as standard double-pane glass, and one-fourth as much as single-pane glass.

Ask the salesperson to tell you the "U-value" of the windows they offer. This is sort of like the miles-per-gallon rating for new cars; an independent agency performs these ratings. In this case, lower is better: the best you can buy today have U-values of around 0.2, while a typical double-pane window is around 0.5.

Note: One thing to keep in mind is that retrofit windows may not be very cost-effective. The cost of replacing windows in existing housing is quite expensive and you typically get payback periods of 20 to 30 years or more. However, retrofit windows will make a substantial difference in the comfort of your home, which could well be worth the cost. Also, double-paned windows typically add to the value and sale ability of your home if you put it on the market. In new construction, the labor costs are equivalent regardless of the quality of window installed, so buy the best you can afford.