Originally published by Michael Bridgeman on the Madison Trust for Historic Preservation's blog on October 31, 2019 following the Wisconsin Historical Society's annual conference. See the original post here.
By Michael Bridgeman
WINDOWS ARE FOR LIGHT AND BEAUTY, NOT FOR INSULATION.
That idea framed Emily Wallrath Schmidt’s presentation about repairing historic wood windows. She spoke at the Wisconsin Historical Society’s annual local historic and historic preservation conference in late October  at the Grand Geneva Resort near Lake Geneva.
Emily is the Preservation Program Manager for the Chicago Bungalow Association which has a long record of helping homeowners repair and restore windows on vintage homes.
The Chicago Bungalow Association website states, “Repair or restoration is a viable option when historic windows may not operate as smoothly as they did when they were new. If windows cannot be repaired, replacements should match the historic window as closely as possible.”
Glass is not a good insulator, no matter how it is engineered, so Emily made the case that, “a properly maintained historic wood window with a storm window has the same energy efficiency as a new window.” She added:
Windows are responsible for about 10 to 15% of residential heat loss according to the Environment Protection Agency. The biggest culprits for heat loss are the attic and roof.
The greenest window is the one you already have. Old-growth wood is literally irreplaceable; it is tighter and more rot-resistant than new wood.
There are no window problems that can’t be repaired with the right know-how, either by the homeowner or a skilled professional.
New windows are not maintenance free. The average replacement window lasts 20 years; and about one-third fail within ten years.
Windows may seem complicated, but they’re really quite simple, at least as when it comes to basic repairs and maintenance like replacing glazing compound, caulking around exterior framing, painting, and minimizing air leaks. For more daunting problems, an experienced professional may be needed.
Like nearly everyone I’ve ever talked to who loves old (or “vintage” houses), Emily strongly discourages getting modern replacement windows for aesthetic, environmental and economic reasons. While acknowledging that replacement windows can sometimes be less expensive than quality window repair, Emily emphasizes that replacements are inferior to well-maintained original windows.
Vince Michael of the San Antonio (Texas) Conservation Society shares that sentiment. Here’s how he started a recent blog post:
Q: Why are they called replacement windows?
A. Because you have to keep replacing them.
For more information, you can check out a number of websites with helpful resources on keeping old-house windows in good condition including the Advantages of Maintaining Your Historic Windows by the Wisconsin Historical Society and 13 Things You Should Know About Retrofitting Historic Windows by the National Trust for Historic Preservation.
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The Local History and Historic Preservation Conference has been held annually since 2007. This year’s conference will be online October 21 through 23. Look for details on the Wisconsin Historical Society website.