Historic Windows

Historic windows are an important and contributing feature to a historic home. Remove them and you are decreasing its historic and aesthetic value.

The removal of historic windows and installation of vinyl replacement windows is a rampant and discouraging problem in the United States—predominantly due to the slick marketing and overblown promises that come from flyers, sales ads, and convincing salespeople.

Vinyl replacement windows have a very short lifespan when compared to historic wooden windows. The “savings” that homeowners are promised won’t be realized before replacement is likely needed.

The Numbers

Only 10 to 12 percent of heat loss in a house is through the windows.  Most is lost through the roof, walls, and fireplaces.

It takes 126 times the energy to manufacture an aluminum window as it does to repair an existing wood window.1

30 percent of “lifetime warranty” windows are replaced within 10 years.1

Consider what window upgrades will bring you the best value for your money?

Wooden parts of historic windows can be replaced.

 Vinyl and aluminum cannot.




Energy efficiency—is it everything it promises?

In 2012, the Federal Trade Commission charged five companies that sell and make replacement windows with deceptive energy efficiency and cost savings claims.2

Policies and funding may promote replacement over repairs despite what research has proven to be the most effective and economical.

“Green”—is definitely not sending repairable windows to the landfill while replacing them with vinyl windows that are not likely to last more than 35 years!

30% of our landfills are construction waste.

Be wary of anything “Maintenance Free”; it often means it cannot be repaired and will end up in the trash.

80% of current window business done by window replacement contractors is replacing windows that are only 15-20 years old.

Getting Started



Simple ways to start decreasing window drafts:

  • ♦  Caulk any gaps or cracks around the window
  • ♦  Apply weather stripping
  • ♦  See Preservation Green Lab study for more information (link below)

Additional ways to reduce drafts without replacing your historic windows:

    • ♦  Storm windows
      • ◊  Interior storm windows
      • ◊  Exterior storm windows
        • −  Be sure to check with the Community Planning and Building Department for any necessary permits and approvals.
        • −  Custom-made storm windows can be purchased—they are low profile and are made to fit the dimensions of the window (even if its corners aren’t “square”).
    • ♦  Insulating cellular shades

Reglaze windows – Easier to do than you might think!

Basic wooden window restoration (re-tie weights, repair stops and sash) can be done by most dedicated DIY homeowners. It just takes time. (Window restoration specialists can also be hired to complete the work.)


Preservation Brief 9—The Repair of Historic Wooden Windows by John H. Myers

Preservation Brief 13 – The Repair and Thermal Upgrading of Historic Steel Windows by Sharon C. Park, AIA

Building Information Center: Windows—National Trust for Historic Preservation


Custom-made high-quality storm windows—Allied Window

Custom-made high-quality wood replacement windows—Green Mountain Window Co

Energy Efficiency: Windows—Common Sense Preservation

Historic Windows and Energy Efficiency—Preservation North Carolina by Sarah Donahue Wolff

Historic Wood Windows Tip Sheet—National Trust for Historic Preservation

“How to Repair Sash Windows” – This Old House by Thomas Baker

Press Release—“New Study Shows Window Retrofits Provide Significant Energy Savings at Less Cost Than Full Window Replacement”

“Saving Windows, Saving Money: Evaluating the Energy Performance of Window Replacement and Retrofit”—Study by Preservation Green Lab

Suggested Books

To learn more about making historic buildings more sustainable, read:
Green Restorations, by Aaron Lubeck.

To learn more about repairing and restoring your historic wooden windows, read:
Window Preservation Standards by the Window Preservation Standards Collaborative.

1 Lubeck, Aaron. Green Restoration: Sustainable Building and Historic Homes. Canada: New Society Publishers, 2010. Print.

2 FTC Fines for Deceptive Energy-Efficiency, Cost-Savings Claims.” Green Remodeling. National Association of Home Builders. 2015. Web. http://www.nahb.org/generic.aspx?genericContentID=187732