"A Fundamental Rethink Of How We Build"

Mr Schlueter, what makes good design?

Good design satisfies the many varied requirements of a construction task. These can be complex and, at times, quite vague - spanning user needs, functional requirements, architectural considerations and, increasingly, sustainability. Ultimately, it's about interpreting the task and putting forward a convincing solution that gets everyone on board, from the client to the town or city and soci­ety as a whole. What I find fascinating is that for every design task there's not just one possible solution, but many.

So sustainability is playing an ever more important role?

It needs to be factored in from the very start. A sustainable solution begins with design: it's about the position and form of the building, its surroundings, what materials it's made from, which energy sources are available, and so on. Right now, some of the most fundamental questions of building are changing dramatically: Should we even build at all? Shouldn't we adapt, densify and reuse what's already there? Once you decide to work with what already exists, the design process flips. You begin with a kind of inventory of spaces and materials, and the challenge is to weave those elements into a coherent whole.

Does that demand different skills from you as an architect?

Absolutely. As an architect, you have to recognise the various interdependencies and make productive use of them in design. Reusing buildings and materials requires a good grasp of processes and logistics, for example, because I need to know which individual materials will become available, and when. This makes it even more challenging to pull everything together into a satisfying whole.

How do you integrate that into your teaching?

We aim to embed climate, sustainability and energy in our teaching from day one. Students should discuss these topics just as naturally as they talk about the urban context, user needs or materials. They need to develop an intuitive understanding of climate-related considerations. My goal is to help them build that intuition - from their first semester at ETH to the day they complete their Master's.

How do you teach something as abstract as intuition?

Intuition comes from experience. Students need to keep practising until they acquire an instinctive feel for how certain choices in their designs will affect the outcome. From this Autumn Semester, our new Studio Foundations course will give Bachelor's students an interdisciplinary perspective on architectural design, taught by a collective of eight professorships. In the Master's programme, our Design for Climate studio intentionally inverts established building practices, giving students the tools they need to integrate ecological sustainability iteratively at each stage of the design process. Armed with that knowledge, they are better able to develop concrete building solutions and understand the consequences of design decisions they make.

You studied architecture, computational design and building systems. Does that still shape your work today?

My perspective on building is still primarily through the lens of architecture. Ultimately, I want to broaden our knowledge and understanding of liveable spaces and improve our ability to build them sustainably. Alongside architecture, I've always been fascinated by engineering and its analytical and methodical mindset. My personal goal has been to bring these qualitative and quantitative aspects together. That's what I strive to pass on to my students. Understanding both of these worlds helps produce a better whole.

As a spin-off founder yourself, do you encourage your students to be entrepreneurial?

I wholeheartedly support spin-offs from my group, though it isn't easy to transfer research to commercial application in construction. Innovation means doing things differently. In construction, that can be difficult or encounter resistance because of the fragmented nature of the industry and the many stakeholders. Nevertheless, we continue to test and showcase new approaches and technologies - for instance, in living labs. Sometimes that sparks interest and momentum for our researchers to take the leap into entrepreneurship.

Can a living lab like the NEST building in Dübendorf accelerate this process?

Living labs foster a dialogue with society and have a big impact beyond academia, both nationally and internationally. They form an important bridge between research and real-world implementation. And they complement the two other modes of research: theoretical work, with its mathematical models and simulations; and lab work, where we test things using physical and experimental methods, in a controlled environment.

NEST also features an adaptive photovoltaic facade developed in your group. Does energy always take centre stage when it comes to sustainability?

For us, yes. Energy affects every dimension of the building process, from indoor climate and the production of building materials to building operation and on-site energy generation using, for ex­ample, photovoltaic modules. All these processes influence a building's emissions and are therefore relevant to its climate impact - but energy is always front and centre.

Have you turned your own home into a living laboratory?

I live with my family in a rental apartment in the city, so there's not much scope there! But we spend much of our spare time in a simple 120-year-old timber house in the mountains that serves as my own little living lab. It's very enriching to transform a building like this, and to see how buildings were built back then and the level of comfort people lived with, compared to today's standards and practices.

We hear a lot about reusing buildings and mater­ials, rather than demolishing and rebuilding - but is that actually happening?

It's certainly not standard practice yet, but there's a lot of research underway and some exciting experiments. There have been a couple of initial projects in Switzerland that focused on reusing as many elements of the building as possible. One of the central questions, however, is how feasible they are in terms of time, logistics and cost. When and where will specific parts be available? And in what quality? Will a reclaimed steel girder still safely carry the load it was originally designed for? Many questions here are still unresolved. Answering them requires nothing less than a fundamental rethink of how we build.

Is there already a shift of mindset in the construction industry?

Construction is still a relatively conservative sector. It's highly localised and fragmented, involving lots of different players. Without a shared baseline of knowledge and practice, it's difficult to reach anything more than minimal consensus. And because this new way of building isn't yet established, it usually costs more. Most people build once in their lives on a tight budget, so there's not much of an appetite for experimentation.

How does Switzerland compare internationally?

There's a clear willingness in Switzerland to take calculated risks and try out new, innovative approaches. In fact, I'm always fascinated by how many people here - private clients, municipalities and construction companies - try to push the envelope, whether in cities or in rural areas.

Does ETH's influence play a role?

Yes, I believe so. There's a lot of interest in collaborating with ETH - for example, on the joint development of prototypes. The Innosuisse Flagship project "Think Earth", which focuses on regenerative construction, currently involves around 50 partners that represent a broad cross-section of Swiss industry. But how much of that ultimately reaches the market varies from case to case, and new developments often take a few years to filter into practice.

New developments in architecture sometimes end up influencing aesthetics.

Aesthetics is always about personal perception - but it's also learned. For years, students have been exposed to a certain way of thinking about and viewing architecture, and that certainly deserves critical scrutiny today. But it's already clear that our prevailing ideas of aesthetics are going to shift.

Visually, how do the newer, more sustainable buildings differ from what we're used to?

Using reclaimed materials, for example, or mounting photovoltaic panels on the facade both change how a building looks. Certain layouts and dimensions become infeasible when you work with simple materials and construction - for example, window apertures may need to be smaller. And if buildings are to provide protection against increasingly hot summers, shading devices on the facade also become relevant. All these things will change the appearance of buildings and influence what we consider to be aesthetically pleasing.

Will we need public backing to get this new aesthetics accepted?

I think a lot of this is about what we're accustomed to seeing around us. Most people don't give much thought as to whether they like a building or not. If we get used to seeing solar panels on a neighbour's facade, or rammed earth walls, they stop being surprising.

And what's architecture's role in that?

Architecture needs to find fresh solutions to these challenges, and this entails questions about building culture and aesthetics. Sustainability is too often associated with restraint and limitations. But there are some excellent examples of buildings that embrace this context as an opportunity to create something genuinely new. In teaching, I find it hard to motivate students by only telling them what not to do. It's better to ask what opportunities the new situation offers, and how this can lead to creative and inspiring ideas for a positive building future.

Is that shift in mindset part of what you envision?

Yes. For our society to change, we need a posi­tive, shared idea of the future - and architecture is the perfect place to have that conversation. It's not just about reducing environmental impact. It's also about asking where and in what way buildings and cities make life more liveable than it would have been if they were not there at all. How can they provide us with renewable energy, clean the air and help us adapt to increasingly hot climates? How can they support biodiversity? It's questions like these that motivate me and my group. They're not utopian - they're genuinely within reach!