The Future of Cities: Interview with ETH Zurich Professor Gerhard Schmitt 

Gerhard Schmitt is Professor Emeritus at the department of architecture of ETH Zurich and the founding director of the Singapore-ETH Center. His research includes responsive cities, urban design and simulation, and urban climate planning. Between 2017 and 2022, he supported the publication of the “Future City Laboratory” series published by Lars Müller, featuring science-based proposals to the challenges big cities around the world face today.

What’s the origin of the cooperation between ETH Zurich and the research institutes in Singapore?

In 2006, when I was responsible for international affairs in the Board of ETH Zurich, we decided to cooperate with peer researchers in other parts of the world where the conditions were different from Europe in terms of climate, culture, geology and governance. The goal was to give PhD students a platform for research in a different culture to gain insights that might be helpful in Asia, Europe, and Switzerland. We already had co-publications with professors at universities in Singapore and this served as a scientific basis for founding the Singapore-ETH Centre. The Future Cities Laboratory was the first large program that started in 2010.

A through line of the books is the importance of dense, mixed-use neighborhoods.

In the 1960s, Jane Jacobs already saw the drastic effects of what happens when cities completely separate working from living: urban sprawl, too much fossil fuel dependent working traffic, the deterioration of downtowns, and the decline of human interaction and diversity. The CIAM Charter of Athens from 1933 is often blamed for this development, which could hardly be anticipated at the time. While some businesses profited from it, society as a whole is grappling with the consequences. Bringing living and working back together in mixed-use neighborhoods could alleviate many problems.

The rise of the home office was a big step toward mixing working and living.

Correct, but cities today can accommodate all sorts of clean businesses, not just service jobs. Small manufacturing firms, such as watchmakers, creative industry, and energy-efficient high precision companies account for a meaningful part of the Swiss urban economy. In inner and outer parts of cities, high-tech urban farms start to re-use buildings, growing fruits and vegetables. The distance from production to the table has shrunk sometimes from 2,000 km to 2 km, saving transport costs and placing less stress on the environment.

Will the population of European cities continue to grow?

Most countries in Europe have reached an urbanization level beyond 70 percent, so their cities will not grow by much anymore. In general, they can grow through country-internal migration, to a small degree by immigration from other European countries, and to an even smaller degree by immigration from outside Europe. Otherwise, their populations will stabilize or even decline, which can be a challenge. Livable and successful European cities such as Zurich and London have up to one third foreign populations and they are attractive places for younger and older people in a balanced way.

So within the EU there is a competition for people. Are cities in Central and Eastern Europe bound to lose it?

Not at all. I was in Vienna during the Cold War and it appeared almost sad and sometimes depressing. After Hungary opened its borders in 1989, many non-Austrians entered the city. Now Vienna is the number one city for livability in the world. With Berlin, Vienna, Warsaw, and Prague, some of the fastest growing cities of the European Union are in Central and Eastern Europe.

How does a city convince a skeptical public about the benefits of adding public transport and bike lanes at the expense of cars?

By giving examples of cities that are already doing it successfully. Such as Copenhagen and Amsterdam, but also Singapore for public transportation in tropical climates. That’s what mayor Anne Hidalgo did in Paris before she proposed her reforms. Yes, people may hate it at first, but they come around quickly when they experience the benefits of less air pollution, less noise, less heat, and fewer accidents. “A rich city is not when all its citizens use their cars, but when its rich citizens use public transportation” is a saying I agree with.

Which city in Europe comes closest to achieving the “15-minute city” ideal? (Work, leisure, healthcare, shopping, culture all within 15-minutes from your home.)

In no particular order: Copenhagen, Zurich, Amsterdam, Milan, Vienna and after the Olympics definitely Paris.

Does urban planning have a solution to the challenges of overtourism?

Overtourism also means that the city is attractive to visitors. A good sign. It’s always easier to reduce the attractiveness of a city than to increase it. To relieve the pressure on over-touristed cities, we should focus on diversification into less visited neighborhoods and into new cities. For example, Switzerland has turned numerous small towns and mountain villages into tourist destinations, places that no one thought of visiting two hundred or a hundred years ago. You can make any place in Europe attractive due to its incredibly rich history.

Another major theme of the books is the urban heat island effect. Cities are becoming dangerously hot in the summer months.

There are always higher temperatures in a city than in the surrounding countryside because the radiation of the sun is trapped as heat in cities – in the paved streets, the walls, the roofs – instead of being reflected or radiating out to the sky at night. In addition, fossil fuel powered trucks, buses, cars, and ships release heat that is then trapped. In most megacities, this heat island effect is drastic. In tropical cities, the urban heat island temperature can be several degrees Celsius higher than in the already hot countryside, which means that people can seriously suffer from heat if they work or spend longer time outside. The urban heat island effect becomes an existential threat.

What can we do against it?

Let’s look at a challenging urban heat island such as Singapore. Every human-made heat source – streets, buildings, cars, trucks – that enters this already hot and humid environment makes the problem worse. In the short term, we need to replace combustion engine cars, buses, and trucks with electric vehicles. This requires more electricity from clean production and not from burning gas in or close to the city. In the medium and long term, the greening of the city is necessary: keeping wind corridors open, planting even more trees, and increasing urban farming.

What should houses be built of? The production of cement for concrete is very energy intensive.

In Europe and regions with sustainable forests: wood. Austria, Sweden, Switzerland and Norway have shown that even tall buildings can be erected from wood, even though most houses are still one or two-story high, which don’t need much concrete and steel. There are century-old examples for resilient wood construction in Europe, Asia and America. Rather than burning wood – releasing carbon dioxide – wood should be used for high-tech construction, from structural elements to insulation. It’s efficient and it’s healthy.

The books emphasize a science and data-driven approach to urban planning. What does this mean?

Cities usually collect all sorts of data using sensors and mobile phones. Instead of a “smart city” that simply gathers this data for companies or the government, we advocate a “responsive city,” where the citizen is at the center of action and inclusion is the guiding principle. Where people are informed, have access to data they and others produce, and can provide suggestions to urban planning. The work of this year’s Nobel prize winners in economics, Daron Acemoglu and James A. Robinson, highlights this issue of good (inclusive) and bad (extractive) governance in their book “Why Nations Fail”.

It’s good to engage people and let them speak their minds?

People have a lot of local knowledge and they like to contribute to improve their environment. They also like the feeling of being heard. If you interact with them and listen to them, resistance to urban plans often turns into support.

Can you give an example?

Take a look at the Science City project by ETH Zurich. In 2003, we knew that we needed to expand the campus from 4,000 to more than 15,000 people on the same size of land and add housing to the science buildings. So, we asked the students in an Internet survey, a relatively new planning method in 2003, where they would like to live and where they wanted to work.

The result was clear: work on the inside of the campus, live on the periphery of the campus with a view to the Alps. That information was given to the planning architect who made a proposal that we showed to the public. But the citizens of the surrounding neighborhoods made a petition against the project to the city of Zurich. After a year of intensive and open communication, and – most importantly – listening to the concerns and proposals of the citizens in the neighborhoods, the project was approved and built without objections. Even two decades later, the “Science City Talks” bring together citizens and scientists and the campus is 95% free of private cars.