The Rise of Retrofit

Chicago shows what's next and what's needed to meet the city's ambitious performance goals.
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From GreenSource
Katharine Logan

Retrofits Thomas is making include sealing floor-to-wall joints, insulating roofs, wrapping pipes, and changing common area light bulbs. "Some of it's common sense and little things," he says, but he's impressed at the difference attention to detail can make. "It might cost you a little more up front, but over the life of the project you'll see the savings, and those are savings that I can pass on to my tenants." With an average expenditure of $59,000, retrofits under the program are typically averaging 28 percent, which, for a typical 24-unit building, is reducing annual operating costs by $8,000 to $10,000.

CNT not only develops initiatives to help citizens and communities reduce energy use, it also has its own house in order, with a LEED Platinum renovation of its 1920s headquarters reaping energy savings of 40 percent. One of the primary goals of CNT's own retrofit was to achieve Platinum certification on a conventional budget. It succeeded through the creative use of "state of the shelf" technology and a focus on the energy efficiency basics: tight envelope, high insulation levels, and high efficiency systems.

Chicago's new Center for Neighborhood Technology is a LEED Platinum certified renovation of its 1920s headquarters, a former textile factory.

Photo © Ballogg

 

CNT is also committed to ongoing improvement. "Measure and improve is a theme through all our building energy work," says Rachel Scheu, CNT Energy's Green Building Research Coordinator (CNT Energy is a division of the Center for Neighborhood Technology). "Go do it," says Scheu, "but then measure your success so that you know what you've done correctly." CNT's energy monitoring tells them that performance varies with changes in occupancy and use: in the years since the initial retrofit, heating and cooling costs have stayed constant, but a significant increase in building occupants has increased plug and lighting loads. For ongoing conservation efforts, this information validates the renovation, and focuses attention on behavioral and operational improvements.

It might be expected that the older the building, the greater the potential for energy savings through green retrofitting would be. In fact, a study by the U.S. Department of Energy tracks building energy use increasing over the course of the twentieth century from 80,000 Btus per square foot in buildings built before 1920, to 100,000 Btus in the 1980s. Older buildings have inherent efficiencies with high mass and smaller windows-and some have already been retrofitted. Environmental Systems Design (ESD), an engineering firm with a record of green innovation in Chicago as well as internationally, is the environmental controls consultant on the retrofit of two Mies van der Rohe buildings in downtown Chicago: the Dirksen Federal Building, completed in 1964; and 330 North Wabash, completed in 1973. "There are thousands of buildings like this across the U.S.," says Andrew Silverstein, vice-president of ESD's commercial and international projects group. "Air conditioning hit its stride at the same time as all-glass transparent facades."

Retrofitting a building of this scale consists of a series of compromises as the design team balances energy performance with a plethora of competing priorities. "If you can think of all the complications on a project," says Brett Taylor at SOM, architects for the Dirksen retrofit, "we have them on that building." Asbestos remediation, historic preservation standards, maintenance of high security levels and, most of all, conducting work in and around the occupants of an operating courthouse: energy conservation is one priority among many.

 

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Originally published in GreenSource
Originally published in November 2010

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