On an island of the Danube in the new district of Donau City, where Vienna’s United Nations complex is located, a neighborhood of social housing towers has recently sprung up, and all but one march to the same drummer. Built with similar massing and height, they differ mostly in exterior styling. In Vienna, as everywhere else in a globalized economy of Manhattanized skylines, high-rise buildings have proved resistant to experimentation and change, constrained by precedent, engineering, codes, real-estate formulas, conservative financing, and the simple physics of the elevator.
Avowed enemies of the box, Wolf Prix and Helmut Swiczinsky, the two principals of Coop Himmelblau, have long believed that varied rather than uniform spaces enrich lives. With the SEG building, a project like any other in the city of Vienna’s workaday “social housing” program, they designed a concrete-frame apartment tower that is conventional in its structure and morphology, but they reconceived the facade, public spaces, and air handling systems in ways that cumulatively radicalize the whole, and create the city’s most significant “green” building. Each of the innovations is simple and relatively inexpensive, but their sum total proves that in architecture, as in chaos theory, simple systems can breed complexity. The architects paid for their innovations by using industrial materials: Galvanized-metal railings, subway grate fences, and other standardized off-the-shelf parts replaced the one-of-a-kind details and elegant materials that the architects usually try to design into their structures.
It is the SEG’s Tower of Pisa profile that first lures people off their usual paths, inviting Viennese to be unexpected tourists in their own town. First, the architects cantilevered each of the 25 floors on the northwest face ever so slightly, so that the entire wall inclines at a 3-degree angle. The coordinated cantilever creates a line of apartments that grows wider on higher floors, so that the top apartments are noticeably bigger than the lower ones, and differently configured: This changing geometry allows different views, and the 3-degree slope of the wall makes the interiors intriguingly, but not uncomfortably, strange.
On the southwest facade, a building-wide glass loggia with operable floor-to-ceiling louvers acts as a protected balcony that extends Vienna’s outdoor season into the winter for all apartments. On the adjacent south-facing side of the building, the architects cantilever generous balconies of differing sizes within a leaning, all-glass, 14-story “climate lobby” fitted with computer-controlled louvers. This vertical winter garden is housed in a corner chamfered to catch breezes and maximize southern light, and residents now water their hydrangeas and geraniums all year long in the company of neighbors above, below, and to the side, as if on the terraced hillsides of Positano, Italy.
Internally the structure behaves like a lung. The climate lobby, an air exchange box on the roof, and an elevator shaft all work together to circulate warm and cool air in summer and winter. Computers control the louvers on the chamfered and inclined glass wall. Here the louvered glass is independent of each terrace, bypassing the balconies and allowing air to circulate so freely that the louvered wall effectively forms a chimney that exhausts up through a vent at the top of the space. The rising hot air draws cool air through a vent off an elevator shaft. The fronts of each balcony are fitted with vents that flap shut in the event of a fire in the atrium. As on the southwest facade, the louvered wall acts to condition the air that forms a protective environmental blanket around the main structure.
There are 10 two-level apartments with double-height terraces within the climate lobby, as well as flats ranging in size from studios to three-bedrooms. The terraces and balconies on the south and southwest faces provide much-appreciated outdoor space. Enclosed in glass, these exterior zones act as greenhouses, buffering the interiors with a protective layer of air. “The content is more important than the form,” observes Prix.
Architects nurtured in the demonstrations of the ’60s are especially conscious about how space helps shape a sense of community, and Prix and Swiczinsky created the open balconies in the climate lobby in what Prix calls a social experiment to warm up the frosty social life which is characteristic of most high-rises. Stacking floors in the usual pancake tends to isolate residents by cutting off any communication between stories, leaving only the lobby, elevator, and landings–venues for passing conversations at best.
In addition to their Positano-like terraces, the architects have placed a clamorous, glass-enclosed bicycle garage next to a generous lobby to encourage community: On the ninth floor, they introduced a “sky lobby” made of several communicating rooms and a sundeck, for formal and informal meetings. The architects earned the space within unforgiving economics by shaving off several inches from the standard thickness of each floor slab; over the height of the building, the inches added up to an extra floor.
The autobiography as a living building can be read on the balcony facades, where cacti, ficus, and philodendra commingle with jeans and T-shirts hanging out to dry. Books sit on balcony ledges next to TV reception dishes. Walter Czerny, on the 20th floor, has become a zealot of his apartment. He likes to lunch in a corner where the balcony juts beyond a concrete structural wall. The small, angular, breathtaking perch, a little like a trapeeze, gives him a vertiginous view of the sailboats and kayaks plying a back canal of the Danube, “This is the spot where I can catch that Himmelblau moment,” says Mr. Czerny. “This is where I fly.”
Chicago architect Louis Sullivan said that a tower should soar, but Emily Dickenson advised, in another context, “Make it slant”–that is, cultivate the unexpected. Coop Himmelblau’s housing is one of the few buildings anywhere that both soars and slants, while performing the social roles of precipitating a sense of community among its occupants and protecting the environment. Within the tradition of social housing in Vienna, the architects have shifted the paradigm from the old socialist model, where the uniformity of the units emphasized the collective identity of the proletariat. The SEG tower instead is all about the individuality of a different era: the variety of the units, plans tailored to each occupant, the uniqueness rather than conformity of the part within a whole, which itself is deliberately and philosophically eccentric. Rare is the high-rise typology rethought–from its skin to its core.