The schoolhouse as we know it has been upended in Leutschenbach, Switzerland, a quiet suburban corner north of metropolitan City of Zurich, Switzerland, where the city is transforming a former industrial site into a mixed-use, middle-class neighborhood infused with green spaces. Rising six stories above the trees, housing developments, and remaining factories, a crystalline new school designed by Christian Kerez not only treats students to sweeping views from the top-floor gym, it represents a clear vision for the future of a community and its children.
The initiative for change began in the mid-1990s. At that time education reforms prompted new guidelines for school construction emphasizing the need for more flexible, sustainable spaces that accommodate current instructional needs like group learning, team teaching, computer workspaces, and early childhood centers. More importantly, since pedagogical concepts are subject to change, a building must be adaptable for subsequent trends. Four schools have been built and 15 more renovated or expanded since 1998. In each case, a project-planning committee made up of school and building authorities, invited programmatic design proposals from architects through an open competition.
“They didn't only give a brief with square meters and functional definitions,” says Kerez about the Leutschenbach call for bids. “They also asked us to envision how a child would experience the school in the future.” Recalling how he enjoyed the large public spaces of his own school and how free he felt running around the grounds, the City of Zurich, Switzerland-based architect elected to “make this a very public building with large halls and staircases.” Additionally, he chose to retain as much of the 177,600-square-foot lot as possible by reducing the building's footprint.
“This was crucial for the quality of the school,” says Kerez. While the land allotment was generous, the site was under the flight path of the nearby international airport and adjacent to a high-speed rail line and factory incinerator. Maintaining an open field with a compact, stacked structure at its center—instead of with a typical two-level building spread over it—would enable the architect to create a park around the school, insulating its occupants from grit and noise while enhancing the developing community.
Once this decision was made, Kerez's solution began to take shape. He developed a scheme for a mid-rise box that fits neatly within a 95- by 148-foot footprint, the dimensions of the school's largest component—the gym. Collaborating closely with structural engineer Joseph Schwartz, the architect devised a bridgelike, steel-frame structure supported by six tripods at grade. An alternating sequence of trusses, internal and external, distributes and bears the building's weight, freeing the design team to cantilever slabs of lightweight, recycled concrete beyond the structural, triple-glazed facade. The resulting balconies provide sunshade and necessary fire-egress, and extend the sense of interior space. The pleated ceilings on the undersides reduce the structure's visual weight, and allow for room heights up to 121/2 feet.
The column-free construction also gave Kerez the ability to satisfy the client's request for open-ended, versatile floor plans. As Leutschenbach serves 500 kindergarten-through-secondary-school children, the teachers requested the ability to separate different age groups as needed. Kerez arranged the interior into four logical sections, one above the other, organized by general function, and unified by a simple palette of materials. Double-glazed, translucent channel-glass walls maximize transparency and light, and creamy terrazzo floors distribute radiant heat fueled by the nearby incinerator. (Indeed, the certified low-energy building is vented naturally through outlets in the roof.)
The children enter on either side of the ground level, which is basically a core with a wide, open area around it. This is where they eat and hang out after class—completely surrounded by unobstructed spans of glass, as if outdoors.
Kerez created a vertical trajectory that directs circulation up two central stairways to the second-, third-, and fourth-floor classroom clusters, nine classrooms lining the sides of each floor. Rather than the typical corridor though, he carved a generous communal area between them for group activities and lessons. Then, he carried this plan up to the fifth floor, tweaking it to fit the shared auditorium, library, and administrative offices around a courtyardlike common.
Saving his most spirited—and daring—move for last, Kerez set the double-height gym directly on top of this volume, as if resting a final layer on a tiered cake. Accessible by elevator or secondary stair, the gym spans the entire upper level, acoustically isolated from the floor below, so races can be run and games played without disturbing the activities beneath them. Not surprisingly, says Kerez, when he asks pupils what they like most about the school, nearly all say the gym.
The unconventional layout is still a challenge for some teachers accustomed to more defined, private spaces. But there is an overall commitment to the concept, says the architect. This was apparent during a recent visit on a blustery Friday afternoon, when the staff seemed to have things well under control as kids of varying ages snacked and played within the vast ground floor.
“I'm glad the students and many of the teachers appreciate the building,” says Kerez. “We did it for them—they spend so much time in the building. We also wanted to pay respect to the site and the people who live here.”
Total construction cost: $51 million
Size: 105,900 sq.ft. / 9840 m2
Completion date: August 2009
Christian Kerez AG
Eibenstrasse 9, 8045
phone: +41 44 454 40 70
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Master builder: Barizzi AG, 8614 Bertschikon, Switzerland
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