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By Nancy B. Solomon, AIA

Natural partners
The preservation of existing structures typically has several inherent sustainable benefits. First and foremost is the reuse of an existing shell and any interior components. These exterior and interior materials embody energy—the energy that was required to harvest, transport, and process the raw materials and to transport and install the building elements. By saving these already manufactured parts, preservationists also save energy. “In terms of a material, the greenest thing you can do is continue its life. Next comes salvage and reuse, then recycling. Specifying new green materials is last,” says Elefante.

Reuse was one of the priorities in the renovation of the S.T. Dana Building at the University of Michigan in Ann Arbor. Built in 1903, the masonry structure was recently renovated by Quinn Evans in collaboration with William McDonough + Partners, in Charlottesville, Virginia. Elefante calculated that, in terms of embodied energy, the building’s bricks alone represent about 135 gasoline tanker trucks of energy. The team also salvaged material from one part of the building for another: Old-growth pine timbers that were removed from a portion of the roof were refashioned into railings and other interior details.

 

The Metzenbaum Building’s shallow floor plates wrap around a courtyard, which affords light and air into the interior offices. The space is being converted into a skylit, public atrium. Image: Courtesy Van Dijk Westlake Reed Leskosky

By saving these already manufactured components, preservationists also avoid adding to the waste stream. According to John Ochsendorf, assistant professor of building technology at MIT’s Department of Architecture, it has been estimated that 140 million tons of construction waste goes to U.S. landfills each year. “If we build buildings well and save the ones we have, we cut back on waste,” says Ochsendorf.

Waste reduction is a significant component of the Metzenbaum renovation program. In addition to reusing the shell and a significant portion of the interior materials, the Cleveland architecture firm of van Dijk Westlake Reed Leskosky (vDWRL) is participating in a pilot program developed by the Cleveland Green Building Coalition and the Cuyahoga County Solid Waste Management District to determine the feasibility of reducing and recycling construction waste.

Nonhazardous waste is separated, quantified, and tracked. According to vDWRL architect and LEED specialist Monica Green, “Most material is being purchased by businesses for reuse. Hardly any is going to landfill.” All waste is being tracked and quantified, and the net profit (sale of waste minus expense of separation) will be compared to local tipping charges to determine if the program is financially viable.

Restoration of an older building on an already disturbed site means less pressure for construction on green sites. And because historic buildings were typically built in downtown settings, they are usually on a transit line and in close proximity to other establishments, thereby maximizing the use of mass transit and minimizing both transportation-related energy consumption and parking space requirements.

Historic renovations often try to specify regional materials and employ local craftspeople: The former reduces the amount of energy consumed in the transportation of goods, and the latter promotes a sustainable local economy. In addition, in the days before synthetics, air-conditioning, and seemingly abundant and inexpensive energy sources, old construction techniques maximized natural materials, natural ventilation, and daylighting—priorities that have been revived with sustainable design. For example, cork flooring, popular in the 1930s, has recently made a comeback in green buildings. Shallow floor plates wrapped around a central courtyard, double-loaded corridors, and numerous operable windows were common in older buildings, such as Metzenbaum. This kind of parti reduces the need for artificial light and offers occupants more control over their space, thereby helping to conserve energy and improve the quality of the indoor environment.