Switzerland’s SUSTAINABLE STRUCTURE

Just outside of Zurich, a structure with swooping rooflines sits high atop a four-story building. This isn’t some billionaire’s penthouse aerie. Instead, it’s an experimental research project meant to create a more sustainable approach to building.

Short for high performance, low emissions, HiLo is the eighth module built upon the NEST building on the campus of two research institutions, Empa and Eawag, in Duebendorf, Switzerland, which are part of ETH university. The NEST building itself is a LEGO-like shelf system, where experimental residential and commercial structures can be constructed.

“The NEST building is a vertical village with a central backbone,” explains Arno Schlueter, an ETH professor of architecture and building systems, who spearheaded the HiLo project with fellow ETH architecture professor Philippe Block. “Its layers are constantly changing and it serves as a way of learning by doing. NEST bridges the gap between lab research and application.”

The approximately 1,300-square-foot HiLo structure—which was designed as office space—was a concept initiated in 2012, says Schlueter. It showcases several sustainable construction innovations.

Most visually striking are the arched rooflines, inspired by gothic cathedrals, which frame large glass walls. The roof’s load-bearing capacity comes from the curved geometry and its lightweight concrete sandwich structure is made of two thin layers of reinforced concrete connected by a grid of concrete ribs and steel anchors. The construction method saves both materials and formwork.

HiLo’s mezzanine floors were also designed to use as little material as possible by employing a rib-stiffened funicular shell instead of flat plate, which allowed for more than 70 percent reduction in material over the use of conventional floor slabs. For further efficiency, ventilation, cooling and heating systems were also integrated into the floor structure.

Under Schlueter’s direction, a solar facade was designed for HiLo. Set in a metal armature, 30 photovoltaic panels were installed on a southwest-facing window to provide some of the structure’s energy needs and act like louvers, shading the glass from too-bright sunshine, yet allowing views and daylighting.

“This solar facade is designed to learn from the occupants,” Schlueter points out. “After a while, the control system knows how to calculate the probability of what indoor conditions are most comfortable for the occupants, and therefore reduce energy consumption.”

Will HiLo’s innovations translate into realworld strategies and products?

“We hope so,” says Schlueter. “This is primarily a research project, but we are always wanting a collaboration to bring this research into the marketplace.”

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