I had been trying to find a new construction window with a low U-Factor when I found SeriousWindows.
The typical new construction window is vinyl, double pane and filled with argon gas. Finding the energy efficiency of windows is tough for both the builder and the consumer. So what are U-Factors and how do they compare with R-Values?
R-Value is a standard measure of heat loss through a partition, such as a wall, window or door. In the past, while the insulating performance of walls has been measured in R-Value and windows have been measured by U-Value. The use of U-value makes it harder for builders and homeowners to see the poor R-Value performance of major brand windows because who the heck knows what it means!
Most new construction windows have a U-Factor of .30 - .27 (lower is better). That equates to an R-Value of 3.3 – 3.7! Ouch! The standard wall the window sets in has an R-Value of 11! Guess where your heat is going?
Serious Windows, Inc has introduced a Series 1125 fiberglass window with triple suspended film and filled with Xenon gas, a U-Factor of .09 (WOW!) and an R-Value of 11. This is just what you need to fight those high utility bills but there is a downside….the cost!
Rumor has it, and that’s all I have to go on since they don’t publish a price list, is that their 1125 Series windows sell for $2,000 – 2,200 each! Ten windows in your new home would cost over $20,000 with SeriousWindows while ten Pella ProLine windows would cost only $4,000. Even adding insulated shades to every window would only add another $2,000 to 3,000 for a total cost of $6,000 to 7,000, a savings of $13,000!
You have to ask yourself if having the best window money can buy to give you a better Energy Star Rating in your new is really worth it. Maybe it is but you better be prepared to live in your home for a long , long time.