Historic Homes: Repair or Replace?
“The Greenest building is the one already built.” -Carl Elefante
Natalie Feinberg-Lopez of Built Environment Evolution located in Boulder, CO says “It's often more energy efficient to leave a historic element rather than replace it with modern technology.” There is an ongoing discussion among Designers, Architects, and Preservationists as to how to bring historic structures up to the energy standards of today without ruining the aesthetics inherent in older buildings. Is it more energy efficient to repair historic windows than replace them altogether? A simple reading of a window's R value can be misleading. Although such measurements can be helpful, one should also consider embodied energy and carbon footprints.
Home owners are often persuaded to replace their historic windows to keep up with current and future energy standards. However, one should take into account how much embodied energy it might take to make a new double-hung wood window look like an old one. In other words, from where was the tree cut to make the new window? An older wood window was most likely cut from local growth and carried by horse and wagon to its destination. Also, there may be some vinyl and metal in the new window that was most likely shipped a long distance to arrive at the historic home site. Finally, and old window most likely contains more biodegradable material than most modern replacements.
With so many new high-tech windows on the market, embodied energy and carbon footprints are rarely considered. So the next time you become enamored with a glossy brochure for the latest and greatest perfectly R rated window, you may want to reconsider and just repair your old one.
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