Classic Look, Modern Efficiency

An older school building can embody the history and tradition of a community. Many schools and universities recognize this by making special efforts to maintain the original architectural appearance of these venerable facilities.

But while many of these structures were built to last, the same can't be said for the windows. The paint peels, the frame deteriorates, and the windows may no longer be effective in keeping the heat or cold out of a building. But even well-maintained older windows might need to be upgraded. Windows installed in buildings as many as 100 years ago don't provide the energy efficiency that a modern window can.

Schools and universities that need to restore their older facilities want the added efficiency of modern window design without compromising the aesthetics and architectural significance that make the building worth preserving. In most cases, with a little extra work, schools can have both.

Preserving the past

At the University of Notre Dame, Notre Dame, Ind., officials make sure that the window replacements and renovations undertaken as part of building restorations match the original architectural designs.

“Our desire is to get as close as we can to the original,” says Debbie Murray, manager of maintenance and programs at Notre Dame.

The key, Murray says, is choosing an architectural firm that is committed to finding the materials needed — either the material used in the original windows or suitable replacements that provide the same look.

“Typically we've tried to find the right architects who can help us find the right products,” says Murray. “The architectural firms work with the window manufacturers and know which ones can provide what we need.”

Not every manufacturer can provide the specialized windows found in many of Notre Dame's buildings.

“In a lot of our buildings, the windows are unusual sizes,” says Murray. “They were custom-made, and the sizes vary, window by window.”

When the time comes to restore windows, the original look may not be obvious. It can be obscured by previous repairs or remodeling.

“We do a lot of research to determine the original color schemes,” says Murray. “We look at old pictures. We really go back and evaluate what the original work looked like.”

Digging up that research can be difficult in some cases, but Notre Dame officials have been able to unearth enough information about the history of their buildings to feel confident about their window selections.

“We can still achieve the look of the original while we are improving on our energy efficiency,” says Murray. “I don't think we've ever had a building where we couldn't find the original plans and had to give up.”

The proper balance

In the Denver school district, many of the windows in older buildings are larger than usual, which means they weigh more.

“The biggest problem we have are with the balances inside the window,” says Bob Berlin, supervisor of welding and metals for the Denver district. “To stay with the architectural design, the windows are so huge that you can't get the window balanced properly. When we replace those windows we weigh the window and try to get a balance for that weight just as close as we can.”

When parts are needed to repair older windows, it's not as easy as heading down to the local hardware store, says Berlin.

“It's hard to find the parts for a lot of the older ones,” says Berlin. “We have to have the parts made for them. Some parts will just not interchange.”

Another potential obstacle in replacing older windows is eliminating hazards that school builders weren't aware of years ago when the windows were first installed.

“A lot of the windows that were installed in the ‘40s, ‘50s and ‘60s used asbestos putty,” says Gary Jefferis, director of operations and maintenance in the Everett, Wash., school district. “We had to remove all of that and replace it.”

In some cases, Jefferis says, the district has had to fill in windows to meet modern seismic codes, but workers have tried not to disrupt the overall look of a building.

As good as old

Windows are battered by the elements over the years. Wooden frames can rot and begin to fall apart, and steel frames can rust and deteriorate.

“With some of our wood double-hung windows, the wood had begun to rot,” says Jefferis. “We manufacture our own wood stops. Some of our steel-frame windows are rusting out, and we are replacing them with vinyl or aluminum frames.”

A few years ago, the Everett district restored Everett High School, which was built in 1910. The newer window systems weren't the same as those used 91 years ago, but they allowed the district to maintain that “turn-of-the-century” look at the school.

“The vinyl double-hung windows let us keep the characteristics of our buildings,” says Jefferis.

Kennedy, staff writer, can be reached at [email protected]. Architect for the renovation of the University of Notre Dame's Main Administration Building is Ellerbe Becket.

NOTABLE

  • 7 TO 12
    Number of years that heat-reducing window film lasts.

  • 68
    Percentage of U.S. commercial buildings that have inefficient, single-pane windows.

  • 40
    Percentage reduction in solar heat gain from windows with low-emissivity coatings, compared with windows with clear double-glazing.

  • 75
    Percentage reduction in harmful ultraviolet rays that windows with low-emissivity coating can provide.

Sources: Energy Efficiency and Renewable Clearinghouse, and the U.S. Department of Energy's Energy Star Windows program.

Keeping history alive

The U.S. Secretary of the Interior's Standards for Rehabilitation provides guidance for what should and should not be done when restoring or replacing windows in older, historically significant buildings.

“As one of the few parts of a building serving as both an interior and exterior feature, windows are nearly always an important part of the historic character of a building,” the guidelines state. “In most buildings, windows also comprise a considerable amount of the historic fabric of the wall plane and thus are deserving of special consideration in a rehabilitation project.”

Some tips:

  • Protect and maintain the wood and architectural metal that make up the window frames, sashes, muntins and surrounds. Use appropriate surface treatments such as cleaning, rust removal, limited paint removal and reapplication of protective coating systems.

  • Make windows weathertight by re-caulking and replacing, or installing, weatherstripping.

  • Repair window frames and sash by patching, splicing, consolidating or otherwise reinforcing. Such repair also may include replacement in kind — or with compatible substitute material — of those parts that either are extensively deteriorated or are missing.

  • For a window that has deteriorated too badly, replace it using the same sash and pane configuration and other design details. If the same kind of material cannot be used, consider a compatible substitute material.

The guidelines also provide several recommendations about what not to do when repairing or replacing windows:

  • Do not remove or radically change windows that are important in defining the historic character of the building.

  • Do not change the number, location, size or glazing pattern of windows by cutting new openings, blocking in windows and installing replacement sashes that do not fit the window opening.

  • Do not change the historic appearance of windows through the use of inappropriate designs, materials, finishes or color.

  • Do not obscure window trim with metal or other material.

  • Do not strip windows of historic material such as wood, cast iron and bronze.

  • Do not replace windows solely because of peeling paint, broken glass, stuck sashes and high air infiltration. These conditions, in themselves, are no indication that windows are beyond repair.

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