The following post is by Brad Kahn:
It’s a question many owners of older homes have asked: Should I replace my single-pane windows or refurbish them? With a torrent of direct mail selling new windows, many people are led to believe the best option to save money and energy is to replace the old windows with new.
Now a new report from Seattle’s Preservation Green Lab sheds light on an answer. And it may be a bit surprising.
The report, Saving Windows, Saving Money: Evaluating the Energy Performance of Window Retrofit and Replacement, concludes that adding storm windows and cellular shades can deliver essentially the same energy savings as full window replacement — at a fraction of the cost.
Applying 80 years of research using energy simulations, the research team found that saving and retrofitting old windows is the more cost effective way to achieve energy savings and to lower a home’s carbon footprint.
Nationally, home energy consumption accounts for 20 percent of total energy use, and Americans spent more than $17 billion on heating and cooling, so the potential impacts of the research are large.
This chart summarizes the key findings across cities and climate zones. The bottom line: Don’t assume you need new windows to save energy and money.
The Preservation Green Lab, a project of the National Trust for Historic Preservation, conducted the research, in partnership with Cascadia Green Building Council and Ecotope. It was funded by the National Center for Preservation Technology and Training.
For a great slideshow about the research and links to the full report visit: http://blog.preservationnation.org/2012/10/02/10-on-tuesday-10-things-you-should-know-about-retrofitting-historic-windows.
Brad Kahn is president of Groundwork Strategies and works with the Preservation Green Lab.