by Russell Boniface
Associate Editor

How do you . . . achieve LEED Gold certification for an adaptive reuse project?

Summary: Lucasfilm Limited’s Letterman Digital Arts Center at San Francisco’s historic Presidio by HKS has achieved LEED® Gold Certification. The 850,000-square-foot, 23-acre Letterman Digital Arts Center is home to several of the company’s film, education, and gaming divisions and is an adaptive reuse of a former military hospital. The center’s four buildings were designed by Gensler, with Dallas-based HKS Architects as executive architect. The buildings’ sustainable design also meets the requirements of the National Historic Preservation Act. Construction was complete in 2006.

A former U.S. military base, the Presidio boasts many architectural styles, including Greek Revival, Queen Anne, Colonial, Mediterranean, and Modern amid its red brick and white stucco buildings capped with terra-cotta roofs. The Letterman Digital Arts Center, named after an army general, is composed of four buildings, two occupied by Lucasfilm and two shared by outside enterprises. The center has a 670,000-square-foot parking garage, the underground placement of which is a key component to the sustainable design.

Green is Gold for George Lucas
Mark Donahue, AIA, LEED-AP, vice president and director of design, HKS, says that filmmaker George Lucas has always had a commitment to sustainable design. ”It was very important to him on a personal level that the buildings reflect that ethos,” he explains. “Gold certification was also a factor by the Presidio Trust for the site. Getting to LEED Gold required a significant effort.”

Donahue says that placing the parking underground was important because “it has the effect of reusing the urban heat island caused by surface asphalt parking. It also prevents runoff from being contaminated with oil and gas, and leaves more of the site for open space.”

The 23-acre site includes a 7-acre park, he points out, with a stream, lagoon, and tree-lined promenade offering views of the Golden Gate Bridge, the San Francisco skyline, and Alcatraz.

The Letterman Digital Arts Center reuses four Presidio buildings that once served as a hospital. Donahue says that one of the interesting green aspects of the project is that the four buildings are oriented in an east-west direction. “This optimizes the relationship with the solar orientation of the sun, so the buildings are easier to heat and cool.” In addition, he says, the buildings in plan are essentially bars of space that are about 65-feet wide. “So there is never a spot on the floor where you are more than 32.5 feet away from a window; people have daylighting and views. On the other hand, because a lot of their operations require dark space for computer graphics and production, there needed to be areas in the buildings where that could be possible.”

Under-floor air delivery system; additional sustainable features
From an energy standpoint, Donahue explains, the entire complex has an access floor with an under-floor air delivery system. “It delivers fresher air closer to people, and you end up not having to punch through this hot layer that builds up near the ceiling. It takes less energy to push the air because basically the entire floor becomes your duct, and friction from the ductwork is limited. Air is distributed through floor vents at each station where there is a person, which maximizes air flow control. They don’t have to condition the air as much because it is not being pushed through the hot air layer. It can actually deliver at a much warmer temperature and still achieve the same comfort goals.”

Donahue notes there have been studies that show people’s ability to control air flow enhances their sense of well being, which underscores the importance of sustainability to George Lucas. “In that industry, employee retention is a factor. You want to hold on to people who build up such a knowledge base.”

Sunlit central staircases to maximize daylight are also part of the design. Other sustainable features at the Letterman Digital Arts Center include high-efficiency plumbing fixtures, materials with a high percentage of recycled content, energy-efficient elevators that use 30 percent of the energy of standard traction elevators, and local and regional materials. The center also is sited near public transportation, and there is bike storage and changing rooms so more people can bike to work. Says Donahue: “The center has layers that build up to a significant sustainable expression.”