For many older school and university buildings, windows are not just one element among many in the design; they are the feature that gives the building its pleasing appearance and historical character.
“Windows are a major element of architectural expression,” says Royce Yeater, an architect and Midwest director for the National Trust for Historic Preservation.
So when administrators decide that windows need to be replaced, they run the risk of tampering with the tradition and history that gives a building special significance.
Fortunately, preservationists say, schools can improve window systems without detracting from the character of a building.
“Schools should realize that today the window industry has made huge strides,” says Yeater. “There are many windows available that look traditional, but have the features and benefits of a modern window system.”
In the 1970s, many schools responded to the energy crisis by reducing the number of windows in their facilities or installing windows that wouldn't let the heat or coolness in from the outside. Some filled in openings with panels. Others installed windows that could not be opened.
But operable windows have staged a comeback. Many teachers, saying they want more control of their classrooms, have clamored for windows they can open or close.
In addition, educators have come to understand that the abundance of windows in older schools was something to be embraced, even though improvements in artificial light made other solutions possible.
“Years ago, some people thought having all those windows was distractive,” says Yeater. “Now we see that the psyche responds well to daylight and it makes students more productive.
Replacement windows can have energy-efficient characteristics of the latest products and still maintain the appearance of the original openings.
“You can get something very close to the original,” says Yeater.
Yeater adds that school buildings that have been designated officially as landmarks may not have as much flexibility in choosing window replacements because of more stringent guidelines that are part of that designation.
Six principles to guide schools in choosing windows for appropriate daylighting levels in classrooms:
Prevent direct sunlight penetration into space.
Provide gentle, uniform light throughout space.
Avoid creating sources of glare.
Allow teachers to control the daylight with operable louvers or blinds.
Design the electric lighting system to complement the daylighting design, and encourage maximum energy savings through the use of lighting controls.
Plan the layout of interior spaces to take advantage of daylight conditions.
Source: The Collaborative for High Performance Schools, Best Practices Manual 2002