February 11, 2008
Greener fact: repair historic windows…don’t replace
Posted by preservationnjorg under Greener Heritage | Tags: historicpreservation, sustainability | 
Contrary to popular belief, studies show that replacing old windows does not always improve energy efficiency and also wastes the energy and resources that went into making them. It also requires the use of new materials to replace them. When maintained properly, historic windows made from old growth wood have a life measured in decades, often in excess of 100 years. And they can be repaired. Modern replacement windows have an average life of 20 years, and usually cannot be repaired, but must be entirely replaced when they fail. And only 20% of heat loss at windows is through the glass.
February 25, 2008 at 10:42 pm
It sure doesn’t help when you get calls and mail from window companies giving out false info to the historic home owner.
I have a neighbor that recently replaced their historic windows with new “energy saving” ones. Sure, the windows will save them money on their energy bill…..50 years down the road! Even as they were installing the new windows they told me they already regretted their decision but at this point it was too late as custom-made windows are not returnable. I tried to warn them but they just didn’t listen. They are now searching for someone to take the old windows off their hands as they are hesitant to throw them in a landfill. What a shame.
Most people don’t realize that often an historic house will need custom windows if they are new and the energy saving costs don’t add up to what they will spend on new windows. If an historic homeowner would like to save energy they should utilize storm windows instead of jumping into new replacements. This is not only a good “green” option but can save the home owner a bundle of money in the end.
There’s a good article from the National Park Service about replacing historic windows, http://www.nps.gov/history/hps/tps/briefs/brief09.htm#Window%20Replacement.
And another from a local historic home owner’s site, http://oldhouseguy.com/index2.html.