For many of our customers researching replacement windows their main goal for the project is to improve the energy-efficiency of their homes.  Done well, replacement windows can offer up to 20% energy reduction in your home.

The overall efficiency of the window is measuring by U-factor, which ranges anywhere from .15 to .30.  The lower the number the better the window does at blocking the heat in the summer, and retaining the heat in the winter time.  Our most popular window has a U-factor of .26 with the standard glass package.  I think a U-factor in this neighborhood is appropriate for our region.  A lower U-factor would be found in triple pane glass packages, which of course require a larger investment from our customers.  It’s my opinion you’d likely never see the return on investment with the energy savings since you’d only see a benefit in the extremes- extreme cold and extreme heat.

Most of the windows we order today include a foam filled frame, the same foam that is put in your refrigerator doors, which reduces the thermal conductivity of the frame.  Additionally we look for windows that have been tested by AAMA for air infiltration- which gives the homeowner an idea of how well built the window is.  Air infiltration and U-factor are pretty dependent on the style of window.  Most of the statistics mentioned above reference a double-hung window, while other styles can vary.  A casement window is the most efficient- it would have the lowest u-factor and air-infiltration rating compared to the same size double-hung.

Ultimately there are many factors that contribute to a window’s energy efficiency.  Give us a call to see some options for your home, and how they might improve your homes comfort and efficiency.