Also, historic windows can be retained and upgraded to approach the thermal efficiency of replacement windows. By adding storm windows to single-pane glass, historic windows approximate the energy ratings of double-glazed replacement windows. Exterior storm windows have an added advantage in that they protect the exterior of the window, lowering maintenance costs, and extending the life of the window.

There is a myth that original wood windows are too costly to repair and require extensive maintenance. What some people fail to realize is that original wood windows can last 75–100 years with proper maintenance and will last another 75–100 years if restored. Typically, replacement windows have a life expectancy of between 10–25 years.

While replacement windows appear to be maintenance free, you cannot maintain or repair them. The best replacement window companies guarantee the glazing units for 30 years, 20 years for the sash. The biggest problem is the short expected life of the glazing. Sometimes after only a few years, the seals break causing the double-glazed windows to fog. Your only solution then is to replace the replacement windows.

In addition to the glazing problem with replacements, you have the issue of visual impact. Especially with vinyl replacement windows, the frame will yellow over time from the sun. Even wood replacements aren’t as durable as original windows due to the fact that they are from second growth lumber, which is more vulnerable to decay and less stable.

Once you begin the “rip out and replace cycle,” it will continue for the life of your home. Our landfills will be burdened with a never-ending supply of failed windows.

Maintenance of original wood windows, even if professionally repaired and serviced, is not as costly as replacing your windows every 10–25 years. But repairing, restoring and maintaining wood windows is easy to do yourself when you break down the task into small steps. An excellent resource on the maintenance and repair of historic wooden windows is Preservation Brief #9 at www.cr.nps.gov/hps/tps/briefs/brief09.htm. In this article, the job is broken down into small easy to follow steps that the do-it-yourselfer can easily follow.

Repairing and maintaining wood windows is less expensive than replacing them. So, if your windows need attention, do not replace them. Preserving original wood windows is better for the environment, saves energy, and maintains the architectural integrity of your home.

*Testing the Energy Performance of Wood Windows in Cold Climates, August 30, 1996. A Report to the State of Vermont Division for Historic Preservation, Agency of Commerce and Community Development