Check out these facts on U.S. energy use:

• Heating and cooling account for about half of home energy use, according to the U.S. Department of Energy
• 40 percent of residential energy use is from homes built before 1970, according to the Harvard Joint Center for Housing Studies
• Energy-efficient windows can save up to 25% on home heating and cooling costs, according to the Department of Energy

Energy-efficient windows are one of the smartest investments a homeowner can make. Not only will they save up to 25% on heating and cooling costs, but they’re one of the top five most cost-effective improvements, according to Remodeling magazine’s annual survey.

High-quality wood replacement windows typically return about 77 percent of their cost on resale, according to the survey.

And here’s another fascinating fact, from the DOE’s Home Energy Saver: When the temperature is 0 degrees Fahrenheit outside, the inner glass surface of a single-pane window is about 15 degrees!

Replacing that old single-pane window with a typical double pane will raise the inner glass temperature to 45 degrees, while a high-efficiency window will yield an inner glass surface temperature of 60 degrees.

The federal government is offering a tax credit of up to $1,500 in 2010 for replacing old windows with new, energy-efficient windows from Marvin Windows and Doors. With ongoing savings on heating and cooling bills – as well as increased comfort and value for your home – it adds up to a compelling case for looking into replacement.

Marvin is offering a free, downloadable 20-page guide to replacement that will walk you through the process, from assessing your current windows to working with a contractor. This could be your window of opportunity for more economical, efficient, comfortable living.

Image courtesy of glenngold via flickr.