ETH-Zurich researchers at the Future Cities Laboratory in Singapore are studying how the rapid population boom in Asia’s metropolises can be rendered sustainable from an urban development perspective. A team is researching robot systems that build multi-storey buildings precisely and efficiently and thus could pave the way for sustainable development.
Singapore is regarded as the Switzerland of Asia: clean, safe, stable. From an urban development perspective, however, there is a glaringly obvious difference. The city state at the southern tip of the Malacca peninsula is home to 5.3 million inhabitants on merely 715 square kilometres, which forces the population density up to over 7,200 inhabitants per square kilometre – around thirty-five times more crowded than in Switzerland.
After all, Singapore is also a striking city of high-rises – number four in the world for skyscrapers. While Switzerland is also a highly urbanised area between Romanshorn and Geneva, smaller and medium-sized towns are strung together here in a medium population density. And compared to the towers on Singapore’s skyline, the tallest building in Switzerland at present, the Primetower in Zurich-West, looks positively dinky.
While Switzerland clearly is not a nation of skyscrapers, eighty per cent of the population live in them in Singapore. So why is Singapore so interested in ETH Zurich’s research on automated tower block construction, despite this difference? “Switzerland offers an exemplary guarantee for quality,” says Gerhard Schmitt, Director of the Singapore-ETH Centre for Global Environmental Sustainability (SEC), where the multifaceted aspects of sustainable urban development are being researched at its integrated Future Cities Laboratory (FCL; see box).
Swiss cities like Zurich and Geneva are famously global frontrunners when it comes to quality of life. This goes hand in hand with cherished traits such as innovative strength, precision and reliability, which are also highly sought after in tower-block construction. The two ETH-Zurich professors Fabio Gramazio and Matthias Kohler seized upon this need with their research module Architecture and Digital Fabrication at the FCL. They primarily study the deployment of robot systems in building high-rises from an architectural perspective.
The designs and models of their lofty, slightly twisted vertical structures are well known. In practice, the famous Weingut Gantenbein in Bündner Rheintal was built by robots and the roof of a new ETH-Zurich test facility on the Hönggerberg is also being manufactured by the digital helpers.
As far as automation is concerned, the construction industry has a lot of catching-up to do and its robot density of forty machines per 10,000 jobs is almost twenty times lower than in many other industrial sectors. Gramazio thus sees key advantages for the small, versatile “elves” from the ETH-Zurich lab in Singapore: “They are extremely precise, affordable and can be used across the board.”
With robots, highly differentiated vertical structures can be built that would not be economically feasible with present-day construction technology. Apart from an interesting appearance, they also allow more design freedom, urban mixing and individuality. Singapore will increasingly have to satisfy such needs in future if, according to official policy, the city is looking to keep on growing – by up to 100,000 inhabitants a year.
However, robots are only one tile in the mosaic of sustainable urban development. Additional housing and office space carries various consequences, which need to be dealt with. As a result, the FCL would like to understand a sustainable development as holistically as possible, which also includes energy consumption and mobility. “Growth needs to be managed qualitatively,” says Schmitt. Therefore, the slogan “cooler and calmer” seems fitting for the Singapore of the future with an increased quality of life – in other words, use energy more efficiently and electrify private transport on a long-term basis.
The enormous amount of waste heat from industry, cars, and air-conditioning units is a major contributory factor to the fact that some parts of the city are up to eight degrees warmer than the undeveloped backcountry. Experts speak of an “urban heat island”. The need for air-conditioning in houses and vehicles is thus one level higher again. One project in the FCL research module Low Exergy examines a radically new arrangement of the supply channels for cooling, electricity and light. Until now, the pipes and wiring were organised under the ceiling in generous volumes. According to the researchers, the integration of the supply systems in ceilings and facades now brings savings of thirty to fifty per cent. In addition, the measures create more space and value for less cost and material input. The new design is more ambitious structurally speaking, but can be accomplished very well by robots.
The builder robots are also part of the vision of the “Vertical City”, following the research of professors Gramazio and Kohler. The model of a 600-metre-high urban structure with 180 storeys provides space for 30,000 people and great opportunities to shape urban life. The porous building structure, constructed by robots (perhaps even flying ones), of course, also allows a lot of freedom as to how the various modules can be organised optimally for living, work and leisure space. This also ensures that this vertical and completely car-free utopia does not descend into a modern Tower of Babel.
Source: ETH Life