ETH zurich's intricate doubly-curved concrete roof tops new research unit in switzerland

ETH zurich finalizes ultra-thin curved concrete roof 

after introducing their ultra-thin, curved concrete roof prototype in 2017, and successfully completing it in 2020, researchers at ETH zurich have now unveiled their finalized innovative roofing in the new empa and eawag NEST research building located in duebendorf, switzerland. boasting an intricate, doubly-curved concrete roof, lightweight funicular floors, and self-learning building technology, the new structure illustrates nearly a decade of the team’s formative research in architecture and sustainable technologies. 

exterior daytime view of the NEST building including the most recent unit HiLo

image by roman keller

combining medieval and futuristic architecture

dubbed HiLo, the latest NEST unit combines medieval building principles with futuristic construction methods. the two-story building with its striking concrete roof and its novel funicular floor system draws influence from the architecture of the past, and is developed using ultra-modern computational design and fabrication techniques.

for this project, a team of scientists led by philippe block, professor of architecture and structures, and arno schlueter, professor of architecture and building systems, together with industrial partners, explored how lightweight structures, efficient construction and intelligent, adaptive building systems can be combined all together. the ultimate goal was to reduce both embodied and operational emissions in the building industry.

exterior view of the NEST unit HiLo from the south

image by roman keller

resource-efficient concrete structures

the innovative roof takes its load-bearing capacity from its distinctive curved geometry, combined with a concrete sandwich structure. this structure is composed of two thin layers of reinforced concrete connected by a grid of concrete ribs and steel anchors. in order to save large amounts of formwork material, the roof was built using a flexible formwork consisting of a tensioned cable net covered with a thin membrane onto which the concrete was sprayed. 

for the mezzanine floors, the researchers used as little material as possible in the structure itself. by employing a rib-stiffened funicular shell rather than a flat plate, the structure’s funicular system uses over 70% less material than conventional floor slabs in reinforced concrete. in addition, digital production methods allowed the integration of ventilation, cooling, and low-temperature heating systems into the floor structure, resulting in an even greater reduction of materials and volume.

the main open space of the NEST unit HiLo with a view towards the east

image by roman keller

learning building technology

the new unit is equipped with an adaptive solar façade, which consists of 30 photovoltaic modules that can be aligned with the sun. these flexible modules can also be used to control how sunlight enters the room to passively heat it or to reduce cooling requirements. 

this solar façade is just one of the many innovative building technology components that have been integrated into the structure, to ensure efficient indoor climate regulation. during operation, the researchers optimized the interplay of the individual technologies using machine learning and considering the users, thus investigating how comfortable indoor conditions can be achieved with as little energy and emissions as possible.

the main open space of the NEST unit HiLo with a view to the west

image by roman keller

research and industry learn from each other

HiLo stands for ‘high performance – low emissions’. the unit allows researchers to test how the construction and operation of buildings can be designed to be as energy- and resource-efficient as possible, while at the same time ensuring an attractive architectural space and a high level of comfort. HiLo is the eighth module in the experimental nest building on the campus of the two research institutions empa and eawag in duebendorf, switzerland (just outside of zurich). in the modular research and innovation building, scientists and industry partners can test and advance new building and energy technologies in temporary building modules or units and under ‘real-life’ conditions.

the main open space of the NEST unit HiLo with a view to the west

image by roman keller

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HiLo offers work and meeting spaces - image by roman keller

the office space on the east side with a view of the adaptive solar façade and the bottom surface of the lightweight floor construction - image by roman keller

view of the lightweight floor construction with integrated building systems from below - image by roman keller

the office room on the west side with a view of the lightweight floor construction from below - image by roman keller

a view of the lightweight floor construction with integrated building systems from below - image by roman keller

top view of the rib-stiffened funicular floor system after concreting - image by juney lee, courtesy of ETH zurich, block research group

the finished doubly curved roof shell - image by stefan liniger, courtesy of ETH zurich, block research group

the finished doubly curved roof shell - image by stefan liniger, courtesy of ETH zurich, block research group

formwork for the rib-stiffened funicular floor system on the west side - image by juney lee, courtesy of ETH zurich, block research group

during installation of the slab formwork, the integrated heating and cooling lines are visible - image by gearoid lydon, courtesy of ETH zurich, architecture and building systems

a thin textile was used for the shuttering layer of the flexible formwork - image by juney lee, courtesy of ETH zurich, block research group

assembly of the 3D-printed formwork components for the rib-stiffened funicular floor on the east side - image by juney lee, courtesy of ETH zurich, block research group

project info:

name: NEST HiLo roof
location: dübendorf, switzerland
project by: ETH zurich