May 1, 2011
Group Effort: The Next Generation 2011 Winner
A large, multidisciplinary team of architects and engineers envisions a zero-energy future for our federal government.
The proposed energy retrofit of a Los Angeles federal building reads like a sci-fi script from Hollywood: a conventional glass-and-concrete office block of the Mad Men era is transformed into a living, breathing “bioreactor” powered by tubes of energy-generating algae, which feed on pollution from cars traveling on the nearby Santa Ana Freeway. Here’s the plot twist: in the closing scene, people would be running to, not from, the aging modernist behemoth. In this architectural saga, a forward-looking design promises to give the old building new life as a healthy, fully empowered, and strikingly beautiful example of sustainability.
This innovative approach to net-zero energy, called “Process Zero: Retrofit Resolution,” has won the 2011 Metropolis Next Generation Design Competition. Developed in partnership with the General Services Administration, this year’s brief was both ambitious and straightforward: bring a typical, energy-guzzling 1960s federal building—an eight-story structure in downtown L.A.—to a net-zero energy standard.
The eighth-annual competition is a showcase of fresh thinking from designers with a decade or less of professional experience. The winning design team is composed of 15 architects and engineers working mostly in the Washington, D.C., offices of HOK and Vanderweil. Their proposal combines an array of proven renewable strategies with something unheard of in architecture: energy-producing microalgae. Employing photosynthesis to grow your own power is a concept as dazzling as the Southern California sun. “It’s never been done in a building,” says Scott Walzak, a 25-year-old junior designer at HOK and the lead exterior designer on the project. “But it’s practical technology in a new way.”
In fact, microalgae are attracting intensive R & D from advocates of clean jet fuel. The tiny plant species produces lipids, or oil, through photosynthesis. Proponents of biofuels have noticed that microalgae produce far more oil (10,000 gallons per acre) than traditional oilseed crops such as soybeans (50 gallons per acre). It’s not yet clear how to affordably extract microalgae oil from each organism, nor is it clear which of the 30,000 or so identified microalgae species would produce the most oil.
Algae are cultivated around the world in “fields” of open ponds to make nutrition supplements. In a sustainable-design context, microalgae offer dazzling qualities in addition to energy: they flourish in and can filter wastewater, and they require sustained sources of carbon dioxide to breathe (researchers have experimented with cleaning industrial-plant emissions by passing dirty air through containers of algae). There’s reason to think microalgae farming could evolve into biopower before the Process Zero designers hit middle age. When asked about its application for buildings, the bioreactor expert René Wijffels, of Wageningen University, in the Netherlands, said, “It’s a question of whether the surface area is significant enough. I can imagine, however, that it could be integrated into buildings.”
The GSA owns more than 362 million square feet of office space and is required to retrofit or replace hundreds of buildings like the one in L.A. in order to cut greenhouse gases 30 percent by 2020. For the competition, Metropolis also asked designers to apply the standards of Living Building Challenge 2.0, a more humanistic and stringent guide-post to sustainability than LEED. “Next Generation exposed us to a number of design solutions that we might be able to replicate throughout our inventory,” says Les Shepherd, GSA’s chief architect and a juror for the competition. “We have several hundred buildings like 300 North Los Angeles in our portfolio, so finding replicable ideas can help us move toward a zero environmental footprint in an economically responsible manner.”
The Los Angeles building clearly needs a retrofit. An eight-story box with roughly 100,000 square feet to a floor, it sits on 4.4 prime acres at the Los Angeles Civic Center. Its clean lines and 20-foot-high lobby were the work of three local legends: Welton Becket (forerunner of Ellerbe Becket), Albert C. Martin (whose sons continue his firm as AC Martin Partners), and Paul R. Williams (the first recorded African-American member of the American Institute of Architects and an AIA fellow). It is also a reminder of the Great Society’s expansion of government services.
Today, tenants such as the Internal Revenue System, the U.S. Bankruptcy Court, and the U.S. Attorneys occupy acres of offices and cubicles. Mean-while, the steel-frame structure, with its single-pane-glass and pebble-studded-concrete exterior, leaks energy like a sieve. Featureless hallways provide a workday experience as unhealthy as eight hours in one of the building’s below-grade offices. Still, there can be daylight at the end of this dreary design tunnel.
Though modernism cast architecture as the perfect machine, the Process Zero team looked instead to nature. Walzak, who completed a master’s degree at Roger Williams University only last year, persuaded colleagues to think abstractly, to see the building as a living cell. “Designers know that the simplest solution is always the best,” he says, echoing his professors.
Developing the algae module and bioreactor fell to Sean Quinn, a 31-year-old sustainable-design specialist for HOK and the lead architect and project manager for Process Zero. Research led Quinn to an emerging technology. Scientists have tested large-scale cultivation of microalgae in horizontal and vertical glass tubes, rather than in open-air ponds. Quinn transferred the mechanics of tube technology to the side of a building, adding a full-scale closed system of holding tanks and filtration ponds to complete the bioenergy network. Inside the glass tubes, the plants swim in a slurry of recycled wastewater and consume carbon dioxide siphoned from an air-intake pipe at the freeway. In principle, photosynthesis would be assured, oxygen pumped out to the street as a byproduct, and oil pressed out of the algae and processed to provide some of the building’s power. Walzak designed the tubular setup as a neat, panelized grid that gives the building far more than a metaphoric green cast.
Team members agree that Walzak’s living cell provided the “Aha!” moment, when biomimicry emerged as their core principle. “It was no longer about countering energy use; it was going back to the beginning,” says John Jackson, a 30-year-old team architect at HOK. As for the algae, “it was definitely an out-there idea, but not so out-there that it couldn’t be done.”
Process Zero argues for fundamentally reengineering the building. For that, Quinn reached for expertise beyond architecture. Jackson recommended his former Penn State classmate Brandon Harwick, an engineer at Vanderweil’s D.C. office, who in turn brought along three colleagues: Patrick Murphy, a project engineer, and Stephen Lahti and Iyabo Lawal, energy modelers from the Boston office.
Harwick crunched daunting numbers. Energy use would need to be reduced from 85,800 Btus per square foot a year to 14,000 Btus, which is the amount of energy he calculated that various solar and algae systems could generate. The first power hog was office equipment, which consumes a whopping 40 percent of the building’s energy. The retrofit plan would save 80 percent of that by removing heat-generating computer processors from every desktop in a building-wide shift to cloud computing.
Artificial lighting accounts for a quarter of the building’s energy load. The solution: introduce daylight to “100 percent of office space” according to the proposal, which cuts three large atria into the windowless interior based on sophisticated modeling. (Research by Ming Hu and Monika Kumor led to an unusual curvilinear form: the shaft design is perpendicular at ground level, but two atria have been rotated to meet the optimum angle of the sun.) Eight additional light wells are punched into the building, shrinking available floor space but flooding the interior with daylight.
“One of the key problems was how to break down walls to allow light to flow,” says Antony Yen, a 31-year-old architect at HOK, who proposed demolishing interior walls and partitions. The Process Zero report concludes that achieving net zero requires “changes in occupant behavior” along with new systems. Yen was happy to replace cubicles with open work space to enhance opportunities for collaboration. “Corporate America is shrinking offices,” he says, and the GSA is “stepping up to convince clients that this is the way to go.”
Heating and cooling systems accounted for another quarter of the energy load. The louvers in the new atria enhance natural ventilation, minimizing the need for artificial cooling. Harwick determined that the primary creature need would be heat. Two systems address that: solar-heated water that radiates heat from the floor, and a more innovative system of “phase-changing materials” installed in the ceiling as high-tech insulation. These PCM modules consist of honeycomblike sheets of wax-filled capsules that possess thermodynamic properties. With changes in ambient temperatures, the wax liquefies (as it absorbs heat) or solidifies (as it releases heat back into a room).
Essentially, the team reduced the building’s energy requirement to what the sun could supply. A thin-film photovoltaic system covers 35,000 square feet of the facade, alongside microalgae tubes and between open-air viewing gardens. Rooftop solar panels are spread over 30,000 square feet of roof, amid the bubbles and louvers of the atria. The microalgae bioreactor would cover 25,000 square feet of the exterior but produce only 9 percent of total energy needs. The system requires infrastructure, separators, and a centrifuge. Harwick, the engineer, left that part of the project to the architects. Cell structure was “all HOK,” he concedes. He remained fixed on the environmental dynamics of the site and the sources of energy that nature could deliver now. “The first things we started looking at are: How do we harvest wind and sun?” he says. “In the sixties, that thought process was not in place.”
Sixties-era architects had “little concern for energy consumption,” says Charles Matta, director of strategic program resources in the GSA’s Public Buildings Service. The best-intentioned architects used single glazing on vast expanses of glass with little attention to solar heat gain. They also “experimented with introducing composite materials and assemblies that didn’t hold up well.” Matta points out another failing of the decade: buildings were rarely conceived as part of the urban fabric, leaving today’s designers with the challenge of reconnecting big, foreboding buildings to their communities.
The value of early interdisciplinary dialogue with engineers led the Process Zero team to a new respect for collaboration and context, hence the project title’s focus on process. “As architects, we have to put our egos aside,” Kumor says. After conducting extensive studies for the atria, she offered new priorities: “First, think about where we are on the planet, about how the site and the climate inform us, then design.”
Quinn worked with Anica Landreneau, sustainable-design director at HOK’s D.C. office, to form the team. Another specialist, Alesia Call, used her background in policy issues to map out future research and a business plan; Colin Benson and Jarek Bieda turned the concepts into striking visuals. Sean Williams, an associate architect from the Tampa, Florida, office, produced the site analysis, which shows concern for water runoff and uses a combination of green and permeable paved spaces. Black water, gray water, and rain are filtered to recharge the algae system. The outdoor ponds and park improve the view from offices above.
As for the algae bioreactor, little is known about how well such an installation would hold up as an architectural element. Growing algae in glass tubes—what researchers call a closed-system tubular photobioreactor—has been done, though not yet profitably. Research has found that excess sunlight can lead to oxygen buildup, which reduces growth and diminishes the potential to produce energy. How many tubes it would take to produce how much energy remains undetermined. Optimists look to the untapped resources of the 150,000 to 750,000 microalgae species still to be studied.
The team offers microalgae as a point of departure rather than a silver bullet of sustainability. They’d be more certain to survive in Los Angeles than in an icy Chicago winter. “Are we saying that all GSA client buildings should be wrapped in algae?” Jackson says. “Absolutely not. But it’s something that should be studied.”
Bill Hellmuth, president of HOK, was awed by the team’s proposal to use microalgae. “The thing I think is so cool is that this is existing technology,” he says. “We know in some application it will work. Will it take research? You bet. But it’s not a space-shot kind of thing.” Reaching for an out-there technology was as natural to the young designers as their fluidity with digital research. Hellmuth marvels at “their ability in real time to do energy modeling and testing of things using computer tools. This generation, it’s part of how they think, how their fingers work. Bringing that technology to the process encourages exploration.”
But Hellmuth sees something else that will distinguish the next generation of designers from those before them: they approach sustainability as a core value. “If you look at the waves of people who are interested in sustainable design, the first wave were moral pioneers,” Hellmuth says. “They dealt through moral suasion. We’ve all come to the conclusion that this is something we have to do in order to survive. This generation takes it from a more pragmatic point of view. They’re asking, How can we take this and create art with it? How can we weave this into our buildings in a much more fundamental way?”