A pioneer of modern timber construction

Even though he is over 80, Appenzell-born Hermann Blumer has no plans to slow down. When we meet him, he is on the way to Brno to give a lecture on two of the most innovative timber constructions of our time. Structures that, without him, would never have existed in their current form.

Pritzker prizewinner Shigeru Ban’s design for the Centre Pompidou-Metz was deemed unworkable until inspiration struck Blumer – a trained carpenter and civil engineer – after months of poring over the problem. “In the end, the solution was quite simple,” he says modestly. A similar scenario arose with Wisdome Stockholm, an extension of the city’s Technical Museum.

Hermann Blumer is the troubleshooter of choice when it comes to translating architectural visions into groundbreaking free-form constructions. He is an avant-gardist who finds beauty – and, it would seem, a kind of artistic expression – in sophisticated ways of transferring loads. Not to mention his undeniable gift for winning over other people with his ideas.

As your family ran a timber construction company, you grew up with wood. What are your earliest memories of this natural construction material?

Hermann Blumer: When I was a boy, I used to love watching the carpenters cutting the wood in the joining yard or the sawmill operators separating the tree trunks into beams and boards. If the work wasn’t too dangerous, I would sometimes even help out. I often went to the woods with my father to saw the barren branches off the fir trees so the wood that grew back would be free of knots. He said that this wood would be there for me later on.

Was it always a foregone conclusion that you would pursue this kind of career?

Yes, I always knew it would have something to do with wood. Building things is clearly in my genes, which drew me to a career as a carpenter early on. Later on, I studied steel and concrete engineering at ETH Zurich and got into information technology. After that, I was able to work on a research project at Karlsruhe University determining transverse tensile stresses in curved saddle roof beams. That was what really helped me to develop and gave me the push I needed to get more involved in working with wood.

You have seen timber construction evolve from being a niche construction segment to the current boom. Did you see this coming at all?

No, I didn’t anticipate this boom or the appeal that timber construction has today. I used to feel uneasy when I saw that wood was being sidelined as a building material, that it had no chance of competing with steel and reinforced concrete. At ETH Zurich, I was the only one of 220 students to focus on wood in their degree dissertation, but there weren’t any separate courses as such. It was only at Karlsruhe University that I was able to get a better scientific understanding of timber. Even more importantly, I was so fascinated by computer technology that I spent a lot of time programming. Even back in 1969, I was saying that we needed to bring these two areas together: timber and computer science.

Which is precisely what gives timber construction a certain advantage today.

Yes, I would even say a very significant advantage! At the research project in Karlsruhe, I had to develop and solve complex mathematical formulas – this gave rise to systems of equations with around 100 unknowns. The computer needed several hours to solve these systems. There were no computer screens in those days – to edit and save your work, you worked with punch cards and keyboards. It was laborious but this basic research was enormously important for the later years.

Why didn’t you stay and pursue a career in research?

When I had been in Karlsruhe for two years, my father fell ill and I went back home to the company, to continue his legacy. At the time, we had a sawmill, carpentry shop and joinery with around 25 employees. The time spent working together wasn’t easy for my father. I was too progressive and constantly called everything into question – and I made a few stupid mistakes too. For example, in 1974 I bought a cabinet-sized computer – a PDP8 from the Digital Equipment Corporation. We were barely able to use it at all because there were hardly any programs for it and, as I said, it didn’t have a screen. You can’t imagine the kind of risks I took back then!

When was the turning point in timber construction for you – the moment you knew that you could do everything you had been dreaming of?

There were three “milestones”. The first was the development of BSB (Blumer-System-Binder), a powerful and also visually appealing connection system for rod-shaped wooden structures. I worked on that for seven years and when I was on holiday in 1978, I had the breakthrough idea. Something that used to take hours – from planning and calculation to transferring data to the CNC machines – now took a matter of minutes. That was a quantum leap and a real breakthrough in timber frame construction.

The second milestone was the development of Lignatur box beams in 1984. This allowed us to build load-bearing ceilings for apartments that had roughly the same strength as concrete ones but with additional functions. Lignatur floor and ceiling elements are very popular in housing today precisely because they are more versatile than concrete ones.

The third milestone was the arrival of the Lignamatic CNC machine in 1985 – the idea actually came to me at four in the morning! I was driving from Hanover to Switzerland with mechanical engineer Fritz Krüsi from the neighbouring village of Schönengrund, and the journey developed into a kind of creative frenzy. By the time we arrived home, we had designed the first ever computer-controlled five-axis processing machine. This suddenly opened up entirely new possibilities in timber construction.

These three milestones were vital in getting us away from the expensive and laborious side of timber construction and ushering in a new era of automation.

You also performed pioneering work in fire safety. What role did that play in the development of timber construction?

Changing the fire safety regulations was actually the fourth milestone that brought about a key turning point in timber construction. The strict fire safety regulations in Zurich only permitted timber constructions with two storeys. Timber faced a lot of discrimination as a construction material back then. We wanted to change that and I started the ball rolling in 1992. Together with Lignum, the umbrella organisation of the Swiss timber industry, we went to the Swiss association of cantonal building insurers and announced that we wanted to make timber buildings more fireproof than concrete and steel buildings. To begin with, they just shook their heads. But it did prompt ETH to begin conducting research, which in turn led to the entire fire safety regulations for timber construction being revised. Switzerland really led the way in opening things up here.

In spite of the current boom, timber construction accounted for no more than 24% of the Austrian market as recently as 2018, measured in terms of total useable floor area in the building sector. Realistically speaking, where do you see the limits for timber construction?

The turning points I mentioned earlier threw the market wide open for timber construction – and there is now a clear trend among real estate developers and architects alike. If you want to survive in architecture today, you have to include timber in your designs or you will lose market share. There are a great many public buildings made of timber in Switzerland today.

But at the same time, you get people asking whether timber isn’t more expensive. That’s actually a rather annoying question. After all, it’s not all that simple to compare reinforced concrete and steel construction with timber construction. Some benefits of timber construction are overlooked and are therefore not factored into calculations. This kind of tunnel vision has been the bane of my life.

And what is your prediction for timber construction?

In the years to come, more and more above-ground constructions around the world will be made of timber because, for ecological reasons, it’s the only real option. Timber never used to be seen as a viable option for the future but today the opposite is true. If you’re building for the future, you use timber. I can imagine timber construction around the world increasing to as much as a third. You can also see this from the fact that many large contractors are now moving into timber. Previously, nothing was made of wood apart from the concrete formwork.

Where do you think the potential of timber construction could be further increased?

We are already well advanced in the area of construction but when it comes to curative timber construction, for example, it’s still early days. In Appenzell, we built the two Mosersweid residential buildings for real estate developer Jan Schoch – larch on the outside and Swiss pine on the inside. These houses are extremely comfortable and there is hardly any need for heating. We are entering a new world where timber is used for more than just supporting or panelling. For example, the wood from Swiss pine actively prevents mould and lowers your heart rate. There are more than 50,000 types of wood in the world. A treasure trove of wood just waiting to be discovered.

You are regarded as a pioneer of timber construction and have had a hand in many innovative solutions in contemporary architecture. Which ones are you particularly proud of?

It was very exciting to work on designs with Shigeru Ban. But it was also very challenging because for every project he came up with a new idea. Sometimes it was almost impossible to implement. People said that it wouldn’t be possible to use timber for the Centre Pompidou-Metz. I had a brief meeting with him at the airport and confirmed that it would be possible. But I had no idea how I would actually go about it. I spent seven months holed up, racking my brains. In the end, the solution was quite simple. And that made all the effort worthwhile.

Other highlights include art projects, some of which appear mystical, like the light sculpture by American artist James Turrell on the Maldives. Or the Emma Kunz Pavilion in my home town of Waldstatt, which I designed together with Norwegian architectural firm Helen & Hard. Emma Kunz was a local artist and alternative practitioner who produced over 500 pendulum drawings on millimetre graph paper, all strictly geometric. My job was to create a walk-in pavilion based on these drawings.

Wisdome Stockholm is one of the most spectacular timber construction projects of our time. How did this come about?

Architects Johan Oscarson and Jonas Elding – together with engineer Florian Kosche – won the competition with a timber gridshell structure. The condition was that timber construction company Stora Enso would provide laminated veneer lumber and cross-laminated timber – in other words, only flat materials. In the planning phase, the project came to me via Blumer Lehmann and I saw that the engineer’s proposal was a reciprocal frame, which did not correspond with the grid support structure in the competition design. This was an immense source of frustration for the architects and the museum company. Then I spent a few days looking for a way to produce and fasten the double-curved and twisted layers using flat panels and timber-to-timber dowel connections. I found the solution and that in turn triggered a radically different approach in the production process.

The Japanese architect and Pritzker prizewinner Shigeru Ban sees you as a kind of kindred spirit. What connects the two of you?

With Shigeru Ban, I always end up in the same kind of situation where I promise something without having any idea how I am going to deliver it. By now, he also realizes that’s how I operate. But of course, this pressure also leads to advancements in construction.

Even though there was a certain language barrier, we were able to sort of intertwine our knowledge in a similar way to the demonstrations with photons by quantum physicist Anton Zeilinger. Shigeru Ban produces statically optimal sketches where you can already see everything.

Just like him, I am always searching. For systems, for solutions and for people to support me. Swarm intelligence among ants is far greater than the intelligence of any individual ant. If you manage to activate this swarm intelligence among humans, you can reach exceptional new heights. So, it’s not just about technical or design aspects but also about the human element.

Even ten years on, the Tamedia building in Zurich is still seen as one of the most visionary feats of timber engineering in the world. How would you explain, in layman’s terms, what is so special about this building?

The story of how it actually came about is very interesting. Shigeru Ban came to Zurich for two hours and when I met him at the airport, he asked me the key question: what advantages does timber have over steel and concrete in a seven-storey building? I didn’t say anything for quite a while and then at some point I began sketching on a pad. My idea was bionic connections with fluid round forms. Two weeks later, I received an architecturally perfect drawing from him. Because it was bionic, he didn’t want to have any steel in the joints. Our engineers simply weren’t able to make it work. Then I had an idea – once again, very early in the morning – namely that we could use large wooden dowels and wooden hole reinforcements as well. After all, some bearings used in mechanical engineering are made of hornbeam. It is actually these joints that are so unique about this building.

Experts in sustainable construction are warning against calling timber construction climate-neutral or carbon-neutral to avoid accusations of greenwashing. Is wood automatically a sustainable construction material or is it still possible to go wrong?

If those of us in the timber construction camp were to do anything wrong, we would soon hear about it! Timber construction is the standard choice when it comes to sustainability. This natural construction material is an excellent basis and leaves all other construction materials way behind.

The construction sector is responsible for 38% of greenhouse gases generated worldwide. Where do you see the greatest potential for rectifying this?

With timber, there isn’t all that much left to do. The others should be saddled with extra costs for the negative effects they have on the environment. That’s the simplest way to get people to learn. Do something stupid and it’ll cost you. If it weren’t for all the lobbying, policies like this would be easy to implement.

In Central Europe, people are always referring to certified sustainable forestry. But can the resource question be resolved regionally in a globalized world?

According to the forestry laws in Switzerland, you are only allowed to consume as much as can grow back again. And it’s much the same in other European countries. It would be great if the timber industry around the world could be a role model for managing resources sensibly. You could safeguard it through the “one cubic metre of timber per capita society”.

What does that mean?

On all continents, one cubic metre of wood per person grows again every year – so we have a ratio of around ten billion cubic metres of timber to around ten billion people. Proportionately speaking, Austria has a little more forest while Italy, for example, has less. If we were to make available one cubic metre of timber to each person, this would be like a kind of share (in the financial sense) or – even more so – like a kind of life insurance. At 400 to 500 Swiss francs (around 420-525 euros) a year, this would be an enormous help to many people.

According to American biologist Edward O. Wilson’s biophilia hypothesis, people have an innate affinity for other life forms like trees. As well as this, it has now been proven that wood has a positive influence on people’s health. Doesn’t this make building with timber more of an urgent priority?

Yes, definitely. The development has already begun in the building of new hospitals. Shigeru Ban and I are currently involved in a project in this area – a six-storey hospital in Ukraine. It’s a fascinating construction, not unlike the Tamedia building. It only consists of pegged timber connections, but this time the construction is made of cross-laminated timber. A local company is providing the elements for this – that’s the only way we could offer this solution in the first place.

Will our connection with nature become even more important in the coming age of digitalization?

If all we do is stare at our phones and no longer notice the flowers growing by the wayside, then things look pretty dismal for humanity. People need nature to avoid losing themselves in technology. I believe that young people need to be taught that again. So they go into the forest and hug trees. Otherwise, the human race has had its day.

You grew up in Waldstatt and still live there – in a small community of 1,750 people right in the heart of the picturesque Appenzell landscape. What do you particularly like about this region?

Thanks to my projects, I have had the opportunity to see lots of different countries but my roots are still firmly in Waldstatt. The landscape there is unique with its hills, scattered farms and the palpable quiet. Even though I have lived in larger cities like Zurich, I have always headed to the hills and mountains at the weekend.

You recently celebrated your 80th birthday. How active are you in timber construction these days?

I’m actually working even more than 100% right now because I’m getting so many requests in. But I also have a lot of people I can delegate to. I haven’t felt my workload go down at all. When I first met Shigeru Ban, I was already 62. My high-profile career only really took off at an age when other people are already retiring.

So you never think of stopping?

Of course, I notice other people overtaking me, but at the same time that’s always relative. They can outpace me in new knowledge but not in experience. But if things continue this way, I will have plenty to do for the next ten years as well.

Interview: Gertraud Gerst
Translation: Rosemary Bridger-Lippe
Photos: Philipp Horak, Hermann Blumer/private, Sweden’s National Museum of Science and Technology/Stora Enso, Sindre Ellingsen/Helen & Hard, Didier Boy de la Tour