"We want to develop an intuition for climate issues in the design"

It's about life cycle assessment data, embodied energy, CO2 values. How do you translate the figures into architecture without them getting out of hand?

There is a great fear that it will become an Excel spreadsheet. But that's not the aim. Thanks to the figures, students should understand how the mechanics behind them work. For example, what effect a change in alignment, building shape, opening areas or material has. That's a lot to ask, it takes experience. But once you have done this often enough, we hope, you may no longer need a tool because you know the rules of thumb. You develop an intuition, similar to that of the supporting structure. An architecture student usually doesn't calculate this in detail, but knows, for example, how thick a ceiling is approximately. Similarly, we want to develop an intuition for climate issues.

What does climate-friendly construction mean for architecture? How will it change?

This is an exciting question, the answer to which we can only guess at so far. There are currently two attitudes. One is aimed at replacing “bad” building materials with “good” ones, for example concrete with wood. The design remains conventional. But if you take the issue seriously, things turn upside down and architecture changes radically. The buildings look different, function differently, are materialized differently. This architecture does not fit into the classic scheme and our viewing habits.

Where the journey will take us is still open.

Currently, most buildings are being built conventionally, but a little better: solar panels on the roof and a different building material. However, climate-friendly construction has the potential to redefine architecture. We lack forms of expression and experience. At final reviews, it is often not easy for guests to judge the designs because they lack reference values. Is it good or bad? Is it architecturally successful or not? Because the architecture can look entirely different.

Can you give an example?

If I build with bio-based building materials, integrate solar panels into the shading elements or consistently align the building and its rooms with the local climate, this influences the architecture. When I extend a building or reuse building elements, the logic of the design is reversed, I rearrange the existing. How do I turn 40 reused windows into a façade? That's different challenge that is unfamiliar at first.

Most buildings are still built conventionally. How can you get architects or clients interested in the topic?

Building owners are increasingly discovering ecological responsibility. Architects are called upon to propose solutions, to educate and inspire themselves and their clients. I hope that the topic will not be outsourced to specialists as it has been in the past and that people will simply call in a climate consultant. I think there is huge potential for architecture. We are standing in front of this white map and there is a lot to discover. This is an exciting moment in construction.

The goal is net-zero. The construction sector is still a long way off. When will architecture be climate-neutral?

I find the net-zero concept difficult because it is very dependent on the balance sheet and leads to statements that are often untenable on closer inspection. The construction industry still relies on plenty of resources that do not come from renewable sources. We need to reduce CO2 as radically as possible. We can only really achieve net-zero if we permanently offset CO2 - for example by using CO2-negative materials. But that is still a long way off, both economically and technically.

What role can CO2-negative materials play?

We have investigated this question as part of the ETH Zurich project “SPEED2ZERO” with researchers from ETH and EMPA. If a material absorbs more CO2 during production than it emits, such as biochar, which can be used for insulation or bricks, it suddenly becomes interesting to use more of this material. It then depends, among other things, on the renovation rate as to how many emissions can be stored in the buildings in this way. However, such materials have so far only covered a fraction of the total building materials, for example for insulation or the supporting structure. We are often a long way from net-zero or even a CO2-negative building, as is sometimes advertised, if we take a realistic view of the balance sheet.

The map is still white in many places. What role does research play in showing the way forward?

Today, we can operate a building almost CO2-free and there are already interesting bio-based building materials. Research is about understanding how the overall system could work. What do we really need? What role do people and comfort play? How can heat or electricity from the environment be integrated into a building and combined with simple storage systems? There is also still a lot of research to be done into the framework conditions, such as business models and social acceptance.

This further increases the complexity. Doesn't this overwhelm everyone?

We also need to work on how things can become 'simpler' again. Research can make a contribution here and highlight the various effects and interactions. The complexity seems like a big cloud. But there are dependencies behind it that can be made visible. In this way, we can show which solutions are good and robust.