Sustainable cities for tomorrow

Sustainable cities for tomorrow
The Urban Mining and Recycling unit (UMAR) by Werner Sobek with Dirk E. Hebel and Felix Heisel at the Empa NEST fulfils the principles of a circular construction industry 

It’s time to revisit the built environment’s relationship with the natural environment

What will the city of tomorrow look like?

With the emergence of new digital technologies, coupled with the deluge of data becoming available through sensors and mobile devices, the city of tomorrow will definitely be more interconnected in many ways at different levels.

The urban dweller experiences a sense of this on a daily basis—with hassle-free electronic banking and smart homes that ‘respond’ to you thanks to a range of sensors, controls and voice-recognition technology. Less obvious is the web of interconnectivity among urban systems, such as electricity, water, transport, emergency services and so on. These hidden connections and interdependencies need to be better understood to make the city of tomorrow more resilient.

“As we continue to experience the effects of climate change, every city urgently needs to take actions to mitigate it.”
Sustainable cities for tomorrow

Hoisting the roof of the Rumah Tambah, or expandable house, in Batam: a sustainable housing unit

The city will also be more connected physically, with more efficient public transport networks and services, shared transport services (such as Grab and BlueSG), and better pedestrian and cycling infrastructure. Despite its small land area of 724.2 square kilometres, Singapore will continue to grow its rail network from about 230 to about 360 kilometres by the year 2030. Jakarta has also started offering its very own rail service to alleviate its perennial traffic woes.

From the perspective of urban planning, it is important to ensure that different districts are well connected and that functions such as residence, work and leisure are better integrated. The increase in mixed-use districts will not only reduce the need and time for commuting, it will also reduce the carbon footprint of individuals and make the city more sustainable.

One of the most often overlooked perspective of connectivity considers how the built environment can be more connected, or in harmony, with the natural environment. As we continue to experience the effects of climate change, every city urgently needs to take actions to mitigate it. How can we satisfy the density requirement to house the city’s inhabitants without sacrificing nature or harming the environment? Given the high demand for energy in almost every aspect of city life, are we too late to put a halt to the climate crisis?

Many urban structures do not consume energy—they guzzle energy. Think air-conditioners in commercial buildings that blast 20 degrees Celsius cool air at office workers clad in sweaters and suits for over 12 hours a day, or shopping malls with façades that lure shoppers with flashy lights 24 hours a day, 365 days a year. These contribute to the operational carbon emissions of buildings. Moving upstream, every building is a complex combination of many processed materials, each of which contributes to the building’s total embodied energy and carbon footprint. Thus, the building and construction sector can play a more active role to decarbonise the industry.

The embodied energy of a building is the energy consumed by all of the processes associated with the production of a building, from the mining and processing of natural resources to manufacturing, transport and product delivery. Taking one step further, in the life cycle of a building, the carbon footprint keeps growing during the maintenance, replacement, deconstruction, disposal and end-of-life phases of its systems and materials.


All around the world, skyscrapers and tall buildings are hallmarks of cities. At the same time, there is growing demand for low-rise high-density cities, thereby allowing the application of more sustainable alternative materials, such as wood or bamboo.

At the Singapore-ETH Centre (SEC), researchers from diverse disciplines develop solutions to make the cities of tomorrow more sustainable, liveable and resilient.

Sustainable cities for tomorrow

Interior of the Rumah Tambah

A team from our Future Cities Laboratory (FCL) is examining how we can tap on regional resources to develop more sustainable alternative construction materials, such as bamboo and mycelium. Another team is incorporating these materials into low-rise housing units designed to respond to the changing needs of the inhabitants and embedding these housing units within a sustainable settlement system. Other teams are quantifying the benefits of our natural assets and developing ways to integrate them into our built environment.

In this increasingly complex world, most problems cannot be solved with a single disciplinary knowledge. Just as integrating nature into buildings requires the knowledge of landscape architects and biologists working together, the introduction of new building materials makes it necessary for material scientists, architects and engineers to work more closely together.

One of the key ingredients that enables researchers at the SEC to develop practical solutions is organising our research based on solution-oriented teams. Disciplinary silos are broken down, and material scientists work alongside architects, cognitive scientists with programmers and urban planners, and so on.

Besides solid research and development in multidisciplinary teams, platforms to test-bed innovative technologies, facilitate dialogues and foster innovation are very important. In Switzerland, the Swiss Federal Laboratories for Materials Science and Technology, also known as EMPA, accelerates the process of innovation in the building sector through the EMPA NEST (Next Evolution in Sustainable Building Technologies). New technologies, materials and systems are tested, researched, honed and validated in realistic conditions in the NEST. The close cooperation with partners from research, industry and the public sector also helps in launching innovative building and energy technologies on the market more quickly.

Specifically, the NEST unit known as ‘Urban Mining & Recycling’ (UMAR) is a residential module featuring structures and materials that can be fully reused, repurposed, recycled or composted when deconstructed. Our colleagues Prof Dirk E. Hebel and Felix Heisel, together with Prof Werner Sobek, devised the concept where new materials such as insulation boards made from mycelium, innovative recycling stones and recycled insulation materials are installed in a building.

Similarly, in Singapore, the ZEB@BCA Academy at the Building and Construction Authority is using the Zero Energy Building to test-bed and integrate various Green building technologies. As a critical test-bedding facility, the 4,500-square-metre building aims to produce enough energy to power itself. It functions as a demonstration project to allow professionals to learn, experience and work together to innovate and develop new knowledge and technologies.

Such test-bedding facilities are a boost to research and development on more sustainable construction technology and materials. In addition, grants such as the Cities of Tomorrow R&D programme sees SGD150 million set aside to activate the whole R&D value chain, from industry to research community and the government, to work together to address urban challenges.

While the building and construction industry and practitioners do their part to make the industry more sustainable through innovative solutions, government agencies and industry associations can further strengthen this culture of innovation. They can provide platforms to foster innovation and exchange knowledge, as well as jointly set standards, such as better walls and windows insulation or standardising the measurement of carbon embodiment of buildings.

Moving forward together, the building and construction sector, with other stakeholders of the city, can shape cities of tomorrow into more sustainable, and therefore more liveable and resilient cities.

Sustainable cities for tomorrow

The UMAR unit by Werner Sobek with Dirk E. Hebel and Felix Heisel applied
and tested mycelium-bound building elements as wall insulation

Sustainable cities for tomorrowPROF GERHARD SCHMITT
Founding director, Singapore-ETH Centre
Professor for Information Architecture, Swiss Federal Institute of Technology Zurich (ETH Zurich)

Dr Gerhard Schmitt is professor of Information Architecture at ETH Zurich (Swiss Federal Institute of Technology Zurich) and founding director of the Singapore-ETH Centre. The centre in Singapore was established in 2010 by ETH Zurich and Singapore’s National Research Foundation (NRF), as part of the NRF’s CREATE campus.

As the centre’s director, he leads an interdisciplinary and multi-university team in developing practical solutions to some of the most pressing challenges on urban sustainability, liveability and resilience. These efforts are channelled through research programmes including the Future Cities Laboratory, Future Resilient Systems, Cooling Singapore, and Natural Capital Singapore. He currently leads the Cooling Singapore project, aimed at mitigating the urban heat island effect; and Big Data informed Urban Design and Governance project.

Prof Schmitt was awarded the European Culture of Science Award in 2010 for initiating the transition of Science City in ETH Zurich towards a zero carbon emission campus in 2007.

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