The Case for Repairing Wood Windows

Making the case for the preservation of old wood windows.

My own house, once on the market as a tear-down, was completely renovated in 1998. The 1904 windows, rebuilt or repaired at the time, continue to serve. My new production windows, added when rear porches were converted to living space, have lost their double-glazing seals and are coming apart at the seams. Not long ago, I saw a trade memo that stated “new window life expectancy” to be 8–20 years.

There will always be good reasons to buy new windows for old houses, including major renovation and additions. Very high-quality windows are being made, with many options available for materials, energy efficiency, and customization. These premium windows are understandably very expensive—and prohibitively so, when considering replacement of most or all of the windows in an old house.

Refitted with chain in the pulley and counterweight system, a historic arch-top window is still doing its job.

Steve Jordan

The replacement industry enjoys legislation that gives tax credits and certifications for replacement materials, based on short-term gains in energy efficiency. Maintenance and repair are not as immediate, or as sexy, but that option deserves a voice.

Repair is achieved through simple, traditional, commonsense (albeit time-consuming) methods. DIY repair costs mostly time; putty and points and paint are cheap. Epoxies and weather-stripping cost a bit more, but nothing like the price of a new window. For those with no skills or no time, specialty window-restoration contractors have popped up all over the country. Depending on how much work needs to be done, the fee will be from about half to fully the cost of a new window, if the problems are extreme. But you’ll have the originals that match the house, fit in existing openings, and can be repaired again in the future.

“It’s easy to take a driving tour of bad replacement windows: shiny white vinyl, stuck-on muntin bars, and flat glass,” says window restoration expert Alison Hardy. “The proportion, shapes, and wavy glass are part of the beauty and character that makes these homes so appealing.”

Older windows can be just as energy efficient as new windows, once they are made weathertight. Look for broken glass, failed glazing, and missing weather-stripping. Comfort is a factor; single-glazed windows can feel cold due to convection currents. However, a storm window over single glazing adds efficiency and comfort at much lower cost than a replacement.

Wood window sash restoration underway: new lights are cut from recycled antique glass.

Kindra Clineff

The Window Preservation Alliance claims that a 30 to 40% savings on heating costs is possible with old windows, and the benefit is immediate. According to the Field Study of Energy Impacts of Window Rehab Choices (conducted by the Vermont Energy Investment Corporation, the University of Vermont School of Civil and Environmental Engineering, and the U.S. Army Cold Regions Research and Engineering laboratory), the estimated first-year energy savings, comparing a restored wood window with a good storm window to a replacement window, came to $0.60. Less than a dollar! In conclusion, they noted, “The decision to renovate or replace a window should not be based solely on energy considerations, as the difference in estimated first-year savings between the upgrade options are small.”

If total energy expenditure to manufacture replacement windows is considered, the period to break even (on fuel savings over replacement cost) stretches to 40 years or more. And most new windows will not even last that long.

Finally, as National Trust president Richard Moe once said, “We can’t build our way out of the global-warming crisis. We have to conserve our way out. . . . we have to make better, wiser use of what we have already built.”

John Van Pelt/OHJ archives; source Keith Haberern P.E., R.A., courtesy the Collingswood (N.J.) Historic District Commission

Weights and pulleys create a superior balance system—when it’s renewed, you can open a sash with one hand. Any draft is more likely coming from a gap at the outside trim, or a poor seal at the floor joists.

Rob Leanna

Do the Math!

A colleague preparing a video asked for help finding a graphic he’d once seen in an energy lecture: the lecturer thought it had come from OHJ. It’s a chart that compared payback periods for various window-upgrade options. We went hunting for it, and found the original in the October 2007 issue. We have not updated it, but prices haven’t changed radically since then. The ratios are certainly the same. (Costs assume a 3′ x 5′ window, installed, and gas heat at $1.09/therm.) If ever there were a sharp stick in the eye for replacement-window salespeople, this has to be it. Even if new windows resulted in annual fuel-cost savings, it would take a very long time to pay back the initial investment cost of the new windows. 

The older the house, the less likely it is that replacement windows will fit or look right. Only custom work using traditional joinery techniques could come close to keeping the originals.

Brian Vanden Brink

Why Keep the Old Windows?

Here’s our summary of the Window Preservation Alliance’s top reasons to repair rather than replace wood windows:

  • Because old windows fit the house, aesthetically and literally. Replacement windows have a rigid structure and are inserted in the existing window openings. Old houses have shifted over time; the gaps that open up may result in draftier conditions than with the originals. Replacement sash is often smaller than the original, for less view and less light.
  • Because the craftsmanship was probably better. The true mortise-and-tenon construction of antique windows is strong, and joints easily repaired. Unique shapes were made possible by the old techniques. Antique windows were built to last, to be repaired as needed, and to remain in use for as long as the house stand. Why send them to a landfill?
  • Because good materials have value. Antique wood windows were made of of old-growth timber, denser and more weather-resistant than today’s tree-farmed softwoods. Delicate muntin profiles are in fact possible only because of the wood density. The wood required no cladding for weather resistance.
  • Because antique glass lends character. Bubbles and distortion are a record of changing technology. The variation of color and texture make the lights (panes) come alive when viewed from the street; the view through them is part of the old-house ambiance.
  • Because a warranty should run more than 20 years. Chances are the old windows have done their job for 60 or more years already. It makes more sense to invest in a proven performer than to sink money into new windows that may have a warranty of eight to 20 years.
  • Because the greenest building is one that is already built. Replacement windows are sold with promises of saving energy. But when evaluated from the perspective of the entire production, shipping, installation, removal, and disposal process, replacing windows consumes much more energy. That is, an older building has a great deal of embodied energy. 

Tags: OHJ August 2020 Preservation Wood Windows

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