December 1, 2008
Form Follows Performance
The German architect Stefan Behnisch pushes architectural form into new energy-efficient directions.
Stefan Behnisch is wearing a flowery shirt with the top buttons open, and he has a wry smile on his face as he strolls through his office in Stuttgart. Around 100 architects from all over the world are at work on three floors, with a tiered backyard garden, tucked into a quiet residential neighborhood. His firm, Behnisch Architekten, is large by German standards—85 percent of offices in the country have only one to three employees—but no contemporary German architect is even half as well known outside of Europe. “We all kind of admire him for going there and paving the way,” says Tillman Prinz, secretary-general of the Federal Chamber of German Architects. “Stefan is the role model for a lot of us.”
Son of the postwar Modernist Günter Behnisch—who designed the 1972 Munich Olympic Stadium and the 1992 plenary hall of the German Parliament, in Bonn—the 51-year-old architect opened his own office in Stuttgart in 1989 and created a distinct reputation for himself by merging contemporary design with high environmental performance in his work for universities and corporate clients. Behnisch is best known in the United States for his award-winning headquarters in Cambridge, Massachusetts, for the biotech company Genzyme. When it opened in 2004, it was the largest LEED Platinum building in the country; it uses waste energy from a nearby power plant for heating and cooling, and daylight to limit the need for indoor lighting. His buildings are like race cars souped up to test the limits of energy efficiency—and Germans expect to drive fast, despite the $7-per-gallon price of gas. Until recently, however, their highly articulated geometries were based on orthogonal units, the standard architectural box.
Increasingly, in projects such as Ozeaneum, the recently completed oceanographic museum in Stralsund, on the Baltic Sea, and a jewellike headquarters for Unilever, opening in Hamburg next year, his use of functionalism and environmental engineering to generate form is causing his architecture to curve and bend. “I was always interested in environmental aspects of design,” he says. “In the past, it had this hippie image, which wasn’t wrong, but that didn’t make it appealing for big companies. I never saw a discrepancy between design and sustainability. I always felt that sustainability could drive architectural form.”
In early work, such as the 1997 Landesgirokasse Bank administrative building in Stuttgart and the Institute for Forestry and Nature Research, in Wageningen, the Netherlands—a 1998 European Union pilot project for ecological construction done within a standard budget using prefabricated products and low-tech, energy-saving techniques—the green strategies are almost inseparable from his human-centered emphasis on program and function. The block-long Landesgirokasse, commissioned in 1992 through Germany’s progressive system of anonymous architectural competitions, combines low-tech tools such as solar orientation, window flaps, and external laminated-wood sun shading to produce a naturally climate-controlled at-mosphere in a five-story office for 1,000 employees. The structure has a rectangular, glass-dominated surface common to many German office buildings, but in contrast to the more bulky ones in parts of Stuttgart, Behnisch’s diffuses the impact of its size with a variety of dynamically tiered setbacks and jutting cantilevers, their position influenced by daylighting, circulation, and thermal comfort. “It was my first major building,” he says as we pull up in his golf-cart-size Smart car. “The whole thing is naturally ventilated; there’s no air-conditioning. We treated it as a highly flexible building with lots of groups and tried to break it open.”
That functionalist logic and environmental specialization has led him to integrate engineers into the earliest stages of the conceptual process, usually bringing them in to collaborate on designs for architecture competitions. “We try to work with experts on different topics from the beginning,” says Martin Haas, a partner since 2005. “We have energy consultants on the team the whole time, and we sit together and develop the best possible ap-proach in terms of programming, layout, lighting.”
Apart from his partners—Haas, David Cook, and Christof Jantzen—his closest collaborators are Tony McLaughlin, at Buro Happold, and Thomas Auer, of Transsolar Climate Engineering. They are working with him on a new science complex for Harvard University, in Allston, Massachusetts, across the Charles River from Cambridge, scheduled to open in 2012. “For me, architecture is content driven,” Behnisch says. “We’re always trying to find the best possible solution for a task. In a lab building, I don’t need it to be very formal, because the functional element adds its own classical modern beauty. And you can work quite innovatively because you are dealing with scientists who are used to thinking out of the box.”
An exhibition currently making the rounds of American architecture schools,Ecology.Design.Synergy, documents Behnisch’s holistic approach to optimizing building performance in collaboration with Transsolar, which also does environmental engineering work with Steven Holl, SANAA, Frank Gehry, and Helmut Jahn. A series of wall panels analyzes the physical properties of the human body as it interacts with buildings and materials. Video installations illustrate Behnisch’s and Transsolar’s detailed environmental studies, such as an animated model showing the effects of prevailing winds and solar gain on airflow within a signature building at a corner of Harvard’s Allston campus. For a 2002 exhibition in Frankfurt, Transsolar suspended a cloud inside the gallery using layers of air with different humidity levels and temperatures, a measure of the control that can be exerted over the climate inside buildings. “We are convinced that we should design buildings with the human in mind,” Auer says. “We do buildings for people. Too many people often forget this. It has to be about quality, and in order to do that we have to understand how the human body works.”
A few days after my visit to Stuttgart, Elke Reichel, a young project architect in the Behnisch office, picks me up in Berlin, and we drive to Stralsund to visit the Ozeaneum, the firm’s latest work in progress. The city was designated a World Heritage Site in 2002 for its medieval town center, and its culture has forever been tied to the sea. Stralsund hopes to draw tourists from nearby Rügen Island to its historic monuments, famous fish shops, and spectacular aquariums. Prime Minister Angela Merk-el is scheduled to arrive for the opening ceremony in about ten days, and when we arrive, having maxed out the speedometer on the rented Ford, the site looks pretty rough. A battalion of workers is suctioning huge pieces of glass onto a five-story atrium, laying down insulating foam and radiant heating pipes, and scurrying around installing exhibits. But the basic spirit is there: four curving white shells, with steel cladding constructed by local shipbuilders, encircle a spacious glass atrium in which entire whale skeletons are suspended from the ceiling. Inside the shells, gigantic aquariums, life-size models of whales sponsored by Greenpeace, and exhibits on the Baltic and North Seas immerse visitors in life under the ocean while educating them about the local environment and the threat of climate change. “The most difficult part of the competition was to find a scheme to section off different parts of the building to make the size smaller,” Reichel says. “Many people wanted to build a shed like an Ikea, with only dark rooms for exhibitions and no windows.”
The Ozeaneum is part of a new series of Behnisch projects that push far beyond the rearrangement of traditional block units, using his commitment to content, performance, and environmental engineering to generate new architectural forms. The functional demands of museums are relatively light compared to a research lab or office building, but aquariums have their own programmatic logic; the massive volumes of water in the tanks have to be treated, requiring an extensive system of compressors, coolers, pumps, and filters, which are hidden behind the tanks. To avoid algae growth in the water and to create a more theatrical experience, most of the live-exhibit rooms have no natural light, so the team orchestrated a circulation route that gives visitors periodic relief from the dark by moving them through the sunny central atrium. The shape of the museum responds to the city’s desire for a signature building that still respects the scale of the nearby shipping warehouses, historic timber-frame houses, facades with flat gingerbread gables, and brick gothic churches.
“It’s kind of exciting to work with these guys,” says Transsolar’s Auer, who collaborated on the project. “Behnisch always had this weird-shaped architecture driven by program requirements, but over the past ten years, climatic- and energy-driven functions became more a piece of the equation. So, suddenly, the facade is not tilted because they think it’s nice; it’s tilted because it has a purpose, because we put a winter garden behind and we want to collect as much solar energy as possible, or we tilt it downward to provide as much shade as possible. So solar- and wind-driven functions, overlaid with programmatic functions, start to become the driver for form. It’s an integral part, and we have discussions from the beginning of the project.”
The new German headquarters of Unilever, opening next year in HafenCity, a former port being developed into a mixed-use waterfront district in Hamburg, is probably Behnisch’s most functionally demanding and formally innovative project so far. It combines the performance and personal-comfort needs of an office with the city’s desire for an alluring building to energize the waterfront while attempting to define a new environmental standard for the country. Behnisch decided to aim for the highest rating from the German Association for Sustainable Building, established last year to stimulate more competition and innovation in green-building design. “Unilever had a very unique program,” he says. “It read more or less like a big Montessori kindergarten: nonterritorial offices, no separation walls, lots of play areas in between. It’s very progressive, open.”
Like nearly all Behnisch projects, it has a large central atrium that brings as much sunlight as possible into the center of the building, which also functions as a public space, with a shop, a restaurant, outdoor seating, and a supermarket to create an active urban site, as well as a place to show off Unilever’s brands. To save energy on heating and cooling, the building employs a slab-cooling system—originally developed by Behnisch for another project and now standard in green buildings in Germany—in which groundwater is pumped into pipes in the concrete slabs to serve as both thermal mass and a geothermal heating and cooling device. The reflexive angles of the exterior appear to be purely stylistic, but the surface is actually a sleight of hand reconciling aesthetics with environmental qualities and budgetary limitations. The faceted double facade is composed of an ETFE membrane (a kind of plastic) stretched over a steel structure on top of a more straightforward building envelope. It protects the operable windows and solar-shading system from strong harbor winds and exhaust from the Queen Mary 2, the gigantic cruise ship docked alongside the museum.
Back in Berlin, Behnisch and McLaughlin present their work as part of a discussion on sustainability in a packed courtyard at the Architecture Forum Aedes, a former brewery complex in Prenzlauer Berg that has been converted into galleries, an experimental architecture school, and studios for artists, including Olafur Eliasson. In recent years, Behnisch has criticized the U.S. Green Building Council’s method of calculating environmental quality using point values that have no relation to energy consumption. German codes are performance based, specifying minimum thermal conservation and maximum energy use depending on the building type, with formulas for calculating solar gains, ventilation, heating, air-conditioning, hot water, and built-in lighting systems.
Compared to the abstract LEED system, the performance-based codes lend precision to the value of green buildings, but Behnisch vigorously defends LEED in Berlin. He gets a big applause from the audience when he talks about his impatience with the rule-obsessed German method of calculating kilowatt hours per square foot without considering comfort and quality. “Here in Germany, we have purely quantitative approaches, not qualitative approaches,” he says. “LEED talks about public space, what you do for the environment around the building, where you get your energy from, natural daylight, visual contact to the outside. But if you look at our standard, it’s all total nonsense because it’s only about quantity, zero about quality.”
He has grown to appreciate LEED’s ability to motivate corporations to outcompete one another, if only for the sake of publicity. “We actually live in a time and a society where the brand and the label become more important than the content,” he says. “In the beginning, we all laughed a little bit about LEED, but in the end it’s a great tool for us. If your neighbor has Platinum, you need at least the same because the client is in the business to make money and rent out buildings. It’s a very simple reflex. Once we market sustainability, we can really integrate it, and it will change and enrich the formal language of architecture.”