Understanding the building

German climate engineer Matthias Schuler is highly sought after by architects - both nationally and internationally. He manages to optimize a building’s energy balance from within, using methods that achieve remarkable results without relying on traditional air‑conditioning systems. Expected with great anticipation as a speaker at ARCHITECT@WORK Munich 2026, we had the opportunity to get to know him in advance through an interview.

You are a mechanical engineer by training and only later found your way into the construction industry. It is no secret that you enjoy tinkering with new solutions beyond conventional approaches. How did the founding of Transsolar come about?

In my first position as a mechanical engineer with a focus on thermodynamics at the University of Stuttgart, I had the opportunity to represent the German Ministry of Research together with the architect Günter Löhnert in an international research project of the IEA (International Energy Agency) on “passive and hybrid solar commercial buildings,” in which 66 buildings from 13 countries worldwide were examined. Over those five years, I learned - as an engineer - how architects evaluate buildings not only through numbers, as we engineers do, but through visual understanding as well, and that the best buildings emerge when architects and engineers collaborate from the very first day of a project.

You quickly realized that architecture needs analytical, diagnostic input. What specific mission did you set for your company?

Based on the findings of the research project, it became clear that universities had developed evaluation methods that had not yet found their way into practical planning - methods that help advise architects in a holistic way. That was precisely what we wanted to do: help build better buildings. And in my first competition, it was a key moment when architects Fritz Auer and Carlo Weber listened to my greenhorn suggestions and then started their design anew, based on my recommendations.

You call yourself a “climate engineer.” What exactly should we understand by that?

We see ourselves as being responsible for the indoor climate, ensuring optimal comfort for users with the lowest possible operational effort. This makes us an additional member of a building’s planning team, responsible for finding holistic solutions throughout the design process - talking to all disciplines and interlinking them with one another. The result is functional design and lower investment in building technology, because the building itself already contributes significantly to a good indoor climate and low energy use.

You once said that architects think in images, while we think in numbers. Where is the interface where you feel both perspectives overlap and can create meaningful change through a shared language?

The shared intention to plan - and ultimately build - something better is the starting point. And once architects understand that we are not imposing anything on them, but rather deriving potentials from local conditions such as climate, soil, surroundings, and their first architectural ideas - what we call “local identity” - and turning those into design suggestions, then the ice is broken. With Helmut Jahn, this process took many years - after all, he was already a star architect when we first met him for the Bangkok airport project. But the Deutsche Post tower in Bonn was ultimately the result of that shared language.

How compatible are modern technology and aesthetics for you? Are there limits where beauty must give way to function?

My collaboration with the Japanese architectural firm SANAA - Kazuyo Sejima and Ryue Nishizawa - is the perfect example. For them, architectural aesthetics always come first, and everything else must fall in line. But it was precisely this mindset that repeatedly led us to new solutions. How can I build a minimally thick concrete wall despite German thermal insulation regulations? This question ultimately led to active thermal insulation at the Zollverein School of Design, where we used the local identity - the nearly 40-degree warm mine water from a depth of 1,000 meters - to temper the uninsulated exterior wall as if it were insulated. The simple monolithic exterior wall construction with integrated pipe coils saved around 1.5 million euros, while the connection to the mine-water system cost only half a million. With the heat provided in this way, other buildings could also be connected to this CO₂-neutral heat source.

You work on projects all across the world. Do you see major differences between continents in the attitude towards and understanding of the need to take active measures?

Yes, there are major differences. In Europe, the drive toward concepts with less technology and lower energy demand stems from a moral responsibility shaped by the legacy of “The Limits to Growth” from 1972 and the Paris Climate Agreement of 2015. In the U.S., however, cost-effectiveness is still - and now increasingly again - the top priority for most clients. When our concepts lead to smaller systems and lower operating costs through multiple uses and efficient utilization, they are readily embraced. But additional costs for a reduced CO₂ footprint are difficult to sell there, especially now that banks have withdrawn from their climate funds. Not to mention the denial by the government in Washington of human-made climate change, which as an engineer and scientist leaves me only shaking my head.

You work with the concept of climate twins. Yet climate predictions continually contradict each other. Is it even possible to build in a climate‑resilient way for many decades - perhaps a century - or does architecture need to be conceived in shorter cycles, which would in turn be unsustainable?

If you look at the flexibility of 100‑year‑old industrial buildings in Berlin, which until now have operated only with window ventilation and heating, and which in the future will also need cooling - once our summers in Berlin frequently exceed 40 degrees Celsius and the number of tropical nights rises to 80 or 90, compared with today’s 20 in warm years - then we must use their heavy construction from the outset to buffer cooling peaks. Our models allow us to simulate this behaviour and its requirements using the future climate data of the German Weather Service. So yes, we must think long‑term, because every construction measure invests CO₂, and that investment should be usable for many, many years - especially since our operational energy sources will emit less and less CO₂ in the future. Denmark is already at this point today, which is why, to obtain a building permit for a new building, they must prove that the CO₂ footprint for construction, 60 years of operation, and deconstruction remains below 12 kg/m² per year.

If you could decide everything: what would be your holistic approach to the future of high‑performance architecture? How would you tackle it?

A high‑performance architecture in our country should begin by upgrading existing buildings and densifying neighbourhoods - even if these buildings cannot be brought quite to the energy standard of new construction. This is because the CO₂ invested in constructing a new building - with the shell alone accounting for almost 60 percent of a building’s CO₂ footprint - can hardly be compensated through operation, especially if our future energy carriers such as electricity and district heating become increasingly CO₂‑neutral or are generated from renewable sources. Reducing heat loss is still a top priority, even though today we know that energy itself is not the problem of the future, but CO₂ emissions. And what we invest today in a new building counts toward today’s CO₂ balance and must therefore be viewed particularly critically. The CO₂ emissions of the coming years will determine whether the global climate crosses a tipping point and becomes unstoppable - whether we believe it or not.