Project DescriptionGovernment Projects
A New Home For The Seattle Office Of The U.S. Army Corps Of Engineers Reinvigorates A Superfund site.
The site for Seattle’s newly opened Federal Center South Building 1202 has taken a drubbing over the years, positioned as it is on the banks of the Duwamish Waterway—a highly industrialized urban estuary that earned an unenviable place on the Environmental Protection Agency’s Superfund list. Occupied originally by a string of organizations with, at best, spotty environmental records (Ford Motor Co., the U.S. Department of Defense, and Boeing), the existing WWII-era building represented the organizational and environmental miscues of past generations. So, when the U.S. General Services Administration (GSA) set out to replace it with a new federal office for the U.S. Army Corps of Engineers (USACE), it targeted ambitious green standards as a way to create a model for reclaiming this toxic ecology.
With the new structure, the design/build collaboration between ZGF Architects and Sellen Construction sought not only a sustainable approach to construction, but also to the experience of the user. Since moving into the old building more than 30 years ago, the USACE had been confined to a space with 100,000-square-foot floor plates and no operable windows. What this expansive footprint made difficult, 6-foot-high cubicle partitions squelched altogether: Natural air and daylight stood no chance of penetrating this space.
Setting out to reverse this effect, the design team undertook extensive massing studies, and determined that an oxbow-shape plan would allow sunlight to reach the majority of the interior spaces, while limiting the western exposure that would drive up solar heat gains. “We considered a lot of variations, but this particular shape really helped to keep peak loads down,” ZGF partner Allyn Stellmacher, AIA, says.
Individual offices and open-plan workspaces line the perimeter of the new building, giving everyone plenty of exposure to daylight. To boost light levels, offices and conference rooms are located around a skylit, garden-filled atrium.
The atrium “provides an amenity for the employees, but it also does multiple things for the building’s energy systems,” says ZGF’s high-performance green building specialist Chris Flint Chatto, Assoc. AIA, citing its role in venting the natural convection exhaust generated in the perimeter offices. The atrium provides measurable energy-performance benefits, but it also renders the workspace qualitatively more pleasant. Now used as a shared communal space, the atrium has become an important connective tissue between departments that were previously segregated. “I’ve worked here for a few years now, and I’ve been meeting people that I’ve never known or interacted with,” says Robert Paulson, a USACE project manager. “There’s a lot of kinetic energy throughout the building,” he adds. “The elevators don’t get used that often, since people now use the building’s many stairs.”
The foundations themselves also integrate different systems. Because the building sits on sedimentatious soil, its piles reach 150 feet deep. Not content to devote that material and energy to a single purpose, the team coupled the piles with hydronic loops for geothermal systems. But the systems are not all below-grade: Chilled sails provide radiant cooling to the interior and a phase-change material tank keeps loads low. And with 100 percent outside air intake, the working environment is noticeably fresher. As part of the contract with the USACE, the GSA will monitor energy performance each month during the first year. Though the first month’s numbers have not yet been compiled, GSA project manager Rick Thomas has heard unofficial reports from the independent group that monitors the numbers, saying, “They look good.”
Even with impressive quantitative objectives, the team was determined to push beyond the metrics that have come to define sustainable design. “We had an ambitious model for energy efficiency,” Stellmacher says. But with every decision, “we were always focused on the workplace environment.”