“We need to make smarter use of existing infrastructure, rather than constantly expanding it”

Why a third generation?
Van Wezemael: Because the ecological ¡°planetary boundaries¡± are forcing us to redevelop existing settlement areas that are in active use. This redevelopment is overwhelming the traditional approaches to cooperation, while the formerly well-established, institutionalised representation of interests is facing a legitimation crisis. In addition, social media fosters a culture of concern and outrage. As spatial planners, we have to learn to deal with this. 

What are some examples of challenges that this new spatial planning generation will need to face? 
Van Wezemael: Many current spatial and mobility-related challenges can now be reimagined thanks to data-driven AI approaches. For example, in Switzerland, as elsewhere, many employees have come to accept home office arrangements and more digital, remote and flexible ways of working ¨C a shift accelerated by the lockdown experience during the Covid crisis. 
For the first time in 200 years, this opens up the possibility of reducing the spatial separation between work and home life, which caused a level of forced mobility, and high traffic volumes. 
Coworking spaces, shared mobility solutions and adaptive traffic management systems are now enabling new approaches to alleviate congestion in commuter traffic.

Rupf: Since the 1990s, there has been a shift from spatial planning to spatial development in terms of study and continuing education at ETH Zurich. This latter follows a more strategic approach that not only asks what is being built and where, but also how living spaces can be developed sustainably and in collaboration with multiple stakeholders. Today, in the continuing education MAS in Spatial Development at ETH Zurich, we are taking things a step further by approaching planning tasks from the perspective of the users and the environment itself.

What does that mean?
Rupf: It is about including stakeholders, facilitating mutual understanding and shaping negotiations to develop sustainable, resilient and regenerative spaces that can also withstand crises, natural events and socio-economic change ¨C all while offering a high quality of life. This requires compelling visions and clear target scenarios for spatial development. That is what we teach in the MAS programme.

What do these new target scenarios look like?
Van Wezemael: The main task of settlement development today is the development of urban agglomerations. However, this is still mainly viewed from the perspective of town centres, which is a deficit-oriented view that we want to move away from. New solutions emerge when we shift our perspective: Small forests located in urban agglomerations are more than just the outer margin at the edge of the settlement area. If anything, when we ¡°read¡± space, we should start with the open spaces and natural environmental resources of the area. In Zurich's Glatt Valley, for instance, it is the Hardwald forest that joins together seven communities, creating a collective identity and a unique quality of life. Here, a good target scenario for the settlement development would therefore be ¡°the Glatt Valley¡¯s own Central Park¡±.

In Swiss cities, there is currently a lack of housing. How can spatial planning help provide a solution to this problem?
Rupf: Fundamentally, there is enough potential to create housing and promote inner development in suitable areas. However, this would require us to re-examine the existing forms of housing and how the space is used in order to save resources and not just increase building density. We should avoid simply continuing to build, as we have done up until now. Unfortunately, today, densification is often only achieved through replacement constructions, which are accompanied by displacements and higher rents, without ecological and socially acceptable inner-city densification. That is why it is important to offer incentives and streamline procedures in order to encourage greater use of the existing building stock, instead of predominantly focusing on replacement constructions. 

In the CAS ETH in Spatial Development programme, you describe cities as the ¡°laboratory¡± of future spatial development. What do such experimental spaces achieve?
Rupf: Experimental procedures allow us to systematically test new approaches ¨C or to justify ruling them out, if results are not convincing. In such spaces, certain rules are deliberately relaxed or suspended: what happens when the guidelines on minimum and maximum density no longer apply? 

Are these laboratories real-world tests for deregulation?
Van Wezemael: No. Spatial development experiments are no different in that they follow clear rules and controlled conditions in order to demonstrate causal effects. However, such systematic impact studies are often missing in spatial development. In this context, selected areas could be used to carry out targeted tests to determine how opening up commercial zones could enable affordable housing. 

Rupf: If there is a shared vision for spatial development, fewer rules are needed. However, if there is a lack of agreement, the need for regulation increases. Rules provide guidance and ensure fairness ¨C however, they do not automatically guarantee location-specific spatial qualities, such as enabling a location to develop its own identity or atmosphere.

What experiments could you run to test such qualities?
Rupf: On a given site, we could test different design options such as various building heights without needing to determine them in advance. AI-based planning tools will become increasingly helpful in simplifying complexity through data-driven approaches. However, to ensure that people genuinely accept the proposals and designs generated by AI, it remains essential that planners continue to review, understand and actively shape these processes.

Your survey of practising spatial planners three years ago revealed a large knowledge gap in terms of climate change and biodiversity. 
Rupf: Spatial development that is adapted for the needs of the climate and sensitive to biodiversity is a field of activity that needs to be urgently addressed. We are also seeing this in continuing education. Biodiversity in particular does not receive the focus it deserves in spatial and urban development. We are now at a critical point for species extinction due to continuous soil sealing and intensive land use. Today, individual measures are no longer able to stop this ¨C and once we lose biodiversity, it is not something that can be easily reversed. That¡¯s why we now need to plan in a more resilient and revitalising way.

What attitude should spatial planning adopt towards sustainability?
Rupf: Today, we need to focus on continuing to develop the existing building stock. There is no one-size-fits-all way of doing this successfully; we need tailored solutions and innovative approaches to avoid further urban sprawl and resource overuse.

Van Wezemael: Good planning, just like good urban design, works with what already exists. That is why, when it comes to the urban climate, we draw upon ¡°nature-based solutions¡±. In structural and civil engineering, we need to make much more versatile use of existing infrastructure than we do today.

What does that mean for you in practice?
Van Wezemael: For example, how do we use cinemas in the morning? Or schools and motorways at night? More broadly, it means that we must learn to make good use of the infrastructure we already have ¨C through intelligent management of time and space. It also means that spatial development should be greatly concerned with markets relevant to spatial planning ¨C such as the false incentives in the rental housing market. And we must make it easier to develop existing building stock, so that it becomes a more attractive option than new construction. 

What alternatives do you see for logistics? 
Van Wezemael: Switzerland is well connected in terms of both technology and transport. We need to make smarter use of existing infrastructure, rather than constantly expanding it or even resorting to tunnelling through the land. For example, digitally coordinated convoys of electric lorries could travel on the left lane of the motorway at night, without disturbing regular traffic. This would not require new roads, new railways or a Cargo Sous Terrain system, just dynamic regulations and intelligent, data-driven management systems.