Around Little Rock, Ark., they call it “Bill’s Bridge.” In a lush setting that was once a brownfield and reaches out towards the Arkansas River, the William J. Clinton Presidential Center & Park is reminiscent of Little Rock’s six bridges that cross the river nearby, its modern design emblematic of a “bridge to the 21st century.” The center, which opened in November 2004, is home to the William J. Clinton Presidential Library and Museum. Designed to LEED Silver certification by Ennead Architects (formerly Polshek Partnership) of New York, the center’s main museum wing rises over a 27-acre city park that stretches along the south bank of the river. Nearby, the refurbished Choctaw Station, a 111-year-old train depot, houses the William J. Clinton Foundation offices and the University of Arkansas Clinton School of Public Service. The library elevated its status further in 2007 when it received Platinum LEED for Existing Buildings (LEED-EB) certification, becoming the only federally maintained facility to earn this recognition.
Collaboration on the building’s concept became a clear theme for architects James Polshek, Richard Olcott, and Kevin McClurkan upon their invitation to the White House in 1999 by then-President Clinton. The president had been impressed with the firm’s cultural and educational projects, particularly the design of the Rose planetarium at New York’s American Museum of Natural History and the art museum at Stanford University. Clinton had given considerable thought to his own presidential library, picturing a public and archival space as an exemplar of sustainable design. Olcott, a founding partner and design principal, recalls, “You won’t find many clients as enlightened as President Clinton. It’s not like we had to convince him to make a green building. It was quite the other way aroundhe was leading the charge.”
Site Development
The project designers met with Clinton every six weeks over the course of a year. Site selection, led by the former president, focused on a long-abandoned rail yard and old warehouses near downtown. “Here, he chose to make a bigger impact by cleaning up this derelict site, to use this urban locale as a catalyst for enlightened development,” Olcott notes. “He immediately saw the possibilities there that others didn’t.”
LESSONS LEARNED
To create transformative change in the built environment of Little Rock, Ark., and the surrounding region, stands as one of the primary goals for the design and construction of the Clinton Presidential Center. “President Clinton’s vision was to create ripples within Arkansas in terms of challenging people, government, and other NGOs to pursue this sort of sustainable construction,” says Jordan Johnson of the Clinton Foundation. Meeting LEED Silver and then LEED Platinum requirements for the library and museum resulted in several lessons. According to Richard Olcott of Ennead Architects and Michael Arny of the Leonardo Academy, these included:
• Broaden use of recycled and reclaimed materials. While green design once called for a series of compromises in material selection, today’s choices are greater than ever (i.e., carpets made of recycled plastics); the center’s structure includes 100 percent recycled steel.
• Future-proof buildings. Although Ennead’s design originally included a green roof, at the time the client decided to use white gravel instead to improve reflectivity (and earn a LEED point). Reaching for LEED-EB Platinum made it possible to complete the green roof, which now provides habitat, reduces stormwater runoff, and improves energy efficiency.
• Reconcile green and federal standards. Gaining approval for a water-retaining green roof and locating the right system proved a bigger challenge than anticipated, Arny says, due to strict National Archives and Records Administration requirements that are in place
to protect records against fire, flood, and
other threats.
• Continually improve building performance. Other than a green roof, the project’s Platinum certification involved no new sustainable building components; rather, its optimized performance may be credited largely to the addition of green building and site operating protocols that comply with LEED-EB standards.
On site, Clinton envisioned bicycling and pedestrian paths, as well as restoration of the old train station and adjacent railroad bridge. In addition to a public park, today the area features nearly a dozen new office buildings.
Natural light represents another signature element in the building’s design and orientation. After visiting the libraries of several former presidents, the architects better understood Clinton’s desire to emphasize openness, accessibility, and light. The National Archives and Records Administration (NARA) dictates requirements for protecting and preserving the artifacts and documents from a presidency, and the rest of the building serves as an active meeting place and policy think tank. “He didn’t want archivists laboring in a dark, vault-like environment,” Olcott says.
Yet prominent use of daylight presented a challenge in such a hot, humid climate. Olcott recalls thinking: “We’ve got a glass bridge that’s facing west. How are we going to keep the sun off it?” The designers first considered placing a system of louvers over the glass, but later opted for a curtain-wall system that incorporates a floating glass scrim, with a sun-screening interlayer and coatings, to reduce solar heat gain by half. Whereas the designers predicted energy performance at 25 percent better than ASHRAE 90.11999, the center currently uses 34 percent less energy than comparable code-compliant buildings. Likewise, potable water reduction strategies total 23 percent less than that permitted by code, for a savings of approximately 324,000 gallons annually.
Continued Progress
Hailed by the press upon its opening, the Clinton Presidential Center has since attracted hundreds of thousands of visitors each year. But the president and his foundation elected to green the three-building complex further. Through a detailed LEED-EB certification process, consultants at Leonardo Academy of Madison, Wis., identified a series of performance improvements. Among them: updated operating procedures for erosion and sedimentation control, as well as updated procedures for green site and building exterior management, and the addition of low-VOC purchasing practices and green cleaning policies. Ninety-four percent of the center’s waste is now recycled and carbon neutrality was achieved via Green-e certified renewable energy credits.
In addition to staff and contractor training, Leonardo Academy also managed the procurement process to install a 5,000-square-foot green roof over the library and oversaw the application for recertification under LEED-EB. The results were recognized with LEED Platinum certification in November 2007.
Olcott takes pride in realizing the president’s original vision as an award-winning green building. “For us, the bridge metaphor captures the spirit of Bill Clinton and his presidency,” he says. “I can’t think of another client we could convince to build a building like that. Certainly an ambitious undertaking for anyone, but it captured his imaginationand it was all new to us then, too.”
David R. Macaulay is the author of Integrated Design: Mithun and the blog Green ArchiTEXT, greenarchitext.com.