Switzerland's Mr Techno-Timber - Hermann Blumer
Appenzell, one of Switzerland’s northern cantons, doesn’t exactly roll off many an international architect or engineer’s tongue - unremarked and unknown in comparison to nearby regional scenes like Austria’s Vorarlberg (an hour east) or Graubünden to the south, both of which have highly visible and world-renowned, architectural-led building cultures. Appenzell is different: outside the central European networks, the canton name triggers approximately zero place recognition when it comes up in conversation regarding Alpine timber culture.
– Photo Shigeru Ban Architects/Didier Boy De La Tour
It's here, though, in northern Appenzell, the hilly canton sitting between Lake Konstanz and the beginning of the Alps proper, that Hermann Blumer, Switzerland’s most internationally influential timber engineer, was born, and where he’s lived for almost the last fifty years. If you visit Maggie’s Manchester Centre, know that it was Blumer who assisted Fosters with the timber. Likewise, if decades earlier, Blumer was on hand in 2004 to help Herzog de Meuron with their ultimately abortive timber sculpture for the Chinese Jinhua park. In recent years, dotted across Europe, North America, and Eastern Asia, a raft of timber buildings have appeared bearing his singular imprint. Though relatively small in number, the projects are testament to Blumer’s out-of-the ordinary influence on turn of the century timber building, and specifically, on the arrival of 21st century timber engineering. They span small bespoke projects such as Peter Zumthor’s St Benedict Chapel: the quirky and exotic, for example Rolf Disch’s revolving Heliotrope solar home in Freiburg, Southern Germany; or the large scale - Norman Foster’s Apple Buildings in Hong Kong, and Helen & Hard’s Finanzpark in Stavanger, Norway.
It is, however, his long-term collaboration with Japanese architect Shigeru Ban, which has made Blumer’s engineering more widely known and internationally visible. Although his name isn’t familiar to many outside the Alpine timber engineering community - the series of Ban projects, beginning with the Metz Pompidou Centre, stopping off with the two Swiss Swatch and Tamedia offices showcases, and continuing throughLa Seine Musical Centre in Paris, Aspen Art Museum in Colorado, and on the Canadian Pacific coast the Vancouver Terrace Row hybrid timber-concrete tower and on to further ongoing projects underway - all these have had a palpable effect on the turn to timber, inspiring the imagination of what could be, as much as what is already is possible.
Blumer is part of a pioneer generation of Swiss timber engineers who are now either on the cusp of retiring or have already done so. The generation also, in the words of the current Head of ETH-Zurich Timber Structures, Andrea Frangi, that started out as carpenters, "working with their hands, and then they started to look at and show how various types of timber steps could be done." Their skills and embodied knowledge have gone on to be incorporated into the timber engineering. The generation, studying and beginning their wood careers' in the 1960s and 70s have been critical to the emergence of the country as the European centre for timber engineering. Apart from Blumer, they also include professor Ernst Gehri, who spent years working on hardwood at ETH Zurich's concrete citadel, Walter Biele, and Julius Natterer, who, though Munich-born, has as Director of the Lausanne's IBOIS wood lab – Further, see the Natterer/IBOIS feature in Fourth Door Review 7 - also helped lay the foundations of the country's current timber turn. During the last of three meetings I've had with Blumer, two autumns ago, he summarised his approach: "We work a little bit different, we look at the detail, and we are also more holistic, simplifying the complexity, a little bit to find out the way. We ask, how can we manufacture, what is the simplest, maybe this beam or post." They operate, he notes, in the in-between space between architect and the main engineering layer of a design team. "It is another way of engineering. To find out the way to do it, in the very early phases." This usually begins with a feasibility study, to look at the direction of the project." Along with Ban, and the Norwegian studio, Helen & Hard, there are a handful of others for whom Blumer and his small Creation Holz team are consultant engineers, including Fosters, and Herzog de Meuron. Blumer has a reputation as the last chance timber engineer, the person you phone when all the previous professionals have given up, knowing that he'll come up with solutions. Architects, he says, "want to know the answers to two questions: 'Can we build it?' and 'How much will it cost?' and then they ask a third: 'Who can build it?'
At that last meeting in September 2019, he had just completed an art sculptural piece in Lindau on the north-east German edge of the Bodensee. The project, symbolising the Ring for Peace's organisation’s pan-religious festival’s 50th anniversary celebrations, was just such an example. Blumer had been approached by a nervous artist who’d begun to get in a sweat that with only three months to go his Möbius Strip design would not only not be ready but wouldn’t even exist. Berlin based artist Gisbert Baarman’s sculptural design had proven too complicated for other engineers. True to his reputation, Blumer worked up a geometrical solution on Rhino software, amending the system stylistically and enabling the art ring’s construction in the tight window of time before the festival’s opening.
He likes to talk of how he often doesn’t have any idea how he’ll solve a problem, but he always says to the architect that, ‘yes, I can do it.’ And then, as he puts it, smiling, he suffers, before the solution does indeed appear out of thin air. This is how it has been with Ban, for whom he continues to be the Japanese architect’s key timber consultant, and how it was with for the Tamedia project, where the proverbial late night lightbulb moment solved the connection system that he’d been wrestling with. A current project is another case in point. The earth artist, James Turrell, involved in building a pavilion on the Maldives Islands, has also turned to Blumer. The design challenge of a pillar-less building skin was resolved by another early hours eureka light going on, adding a hole in the middle of the structure, which again the original engineers’ thought hadn’t been possible.
Two years off eighty, Blumer may be slowing down some, but he continues to be involved in various new projects, including Ban’s current workload, which includes the Kentucky Owl Park (currently in its early viability phases), a visitor centre consisting of three timber pyramids for the Kentucky Owl Bourbon Distillery, each pyramid featuring different aspects of the whisky preparation processes.
But Blumer’s story is about far more than helping famous starchitects to realise their impossible designs. All through his career and life he has been creating, developing and realising new timber technologies, whether furthering glulam, developing machinery, or supporting the emergence of engineered hardwoods. It is a passion, likely bordering on obsession. As he has noted, “Wood construction engineering has fascinated me since my early years and still fills me with joy and pride.” The successive start-ups and companies have followed in the aftermath of Blumer’s inventions and innovation, while he moves on, spurred by the next steps and ideas on the list that he's envisaging. It is this fuller story that this piece profiles. For all this, Blumer comes across as unassuming and a modest man, fundamentally shy probably, someone who doesn’t care for the limelight. Bespectacled and a mite stocky, he is clearly super-passionate about timber, believing in its critical role in the future and envisaging its broadening applicability in many contexts across the earth. “As a sustainable material, wood enables us to move towards an economic model whereby resource usage is in harmony with our planet and one which will provide future generations with a basis of existence.”
Born in 1943 in Herisau, northern Appenzell’s largest town, and like so many others involved in this generational shift, Blumer’s background is in the woody overlap of forestry and carpentry. His grandfather began and built up a carpentry factory and his father trained as a forester before continuing the family business.
Blumer junior was also apprenticed as a carpenter, heading off to Switzerland’s southern Valais canton between 1958 and 1961, before enrolling in a civil engineering degree three years later, in 1964, at one of the Continent’s technical powerhouses, ETH-Zurich. He was, he says, the only one out of the year’s 220 students who elected to focus on wood. “I was the sole one who wanted to.” After graduating in 1969, Blumer taught at Kassel University for two years, beginning to pick up on the very earliest ripplings of the digital revolution, and buying a PDP-8 data processor in 1974. One of the earliest computers available to the general public, through today’s eyes the machines look unbelievably clunky, and take up as much space as a refrigerator. The first PDP-8 was launched in 1965 by the Digital Equipment Corporation, with new models being released well into the 1980s. By then Blumer had moved back to Appenzell, as in 1971 he took over running his father’s sawmill.
Washington, DC – Credit, Photo Wikipedia/AlkivarPublic Domain
At that time, the early 1970s, a cluster of cultural forces were beginning to coalesce in ways which were to have, both directly and indirectly, a long-term influence on the young engineer. The emergence of contemporary environmentalism was beginning to gain a significant foothold across Southern Germany, as well as neighbouring Switzerland and Austria. Forests and trees played a part in the prehistory to this regional coming of the greens. Acid rain, first identified in the late sixties, was turning into a major issue, large tracts of forests dying and colouring the decade, not least across forested Southern Germany and, though with lesser intensity, Switzerland. Throughout the region - and across pockets of Europe whole – there was also the beginnings of an environmental building culture. In parallel, the regional Alpine and southern German forest and timber industry was facing an increasingly challenging future. Switzerland, like all of Europe, was still very much gripped by the perception that timber belonged to the past: the future was concrete, steel and glass. This was the professional dominant materials consensus, and together with ever greater mass production, had so marginalised timber as a construction material that it seemed to be in a spiral of terminal decline, the sector close to being extinguished.
Amidst this and though small-scale, a new interest in timber was also evident, interest which had begun translating into actual buildings. Most projects were domestic, but there were a few larger non-residential projects as well. With eyes on the horizon, small networks of generally youthful builders, architects and engineers worked on developing new approaches to building, to structures, to technologies and to materials, which sought to be responsive to and integrate environmental concerns. Wood, as a renewable material, was at the heart of this new green construction and architectural culture, which was in effect taking its first infant steps. Some in the timber building sector took note. There was opportunity here. With the development of the right machinery, timber could be a material source for mass-produced building components, at the structural as well as joinery or façade levels. If there was active interest, there were also divisions amongst some at the time, often around whether such moves reproduced the mass production of the mainstream and what this could mean for the future of carpentry, of craft and associated skills. The majority, though, pragmatically, saw the future in exactly such industrial terms.
This is something of the regional context that Blumer was working in through the seventies in taking on the management of his father’s Waldstatt sawmill. Appenzell may be little known outside specialist circles; what soon becomes apparent though is that the various companies and initiatives that Blumer helped get started are part of a wider web of small companies which mutually supported each other and grew together. This is of a piece. Small, industrious Swiss companies, overwhelmingly male, often focusing on technological equipment, and often getting started through solving one or another technical challenge that unlocks next commercial steps, are very much part of a central Europe model, supported by and supporting, in Switzerland at least, an emphatic Protestant work ethic.
Glulam was where Blumer began. Although already over 100 years old, it was essentially in its infancy, a new timber material. The glue laminated beam and columns – often traced back to Otto Hetzer’s 1872 initial production in Weimar – was one of the few engineered timber technologies available, and despite its formaldehyde glues packing a killer toxic punch, this particular industrial material was an immediate mainstay of buildings’ ecological future. It isn’t surprising then that an early focus of the engineer was on expanding the repertoire of structural glulam.
Throughout the decade Blumer worked on developing a new glulam connection system. Working with ETH-Z’s only timber department, led by Professor Ernst Gehri, issues around the design of connections were gradually resolved. Computing power, initially including the PDB-8, was crucial for running the numbers, and in 1978 (the same year that Hundegger were founded) the first version of BSB - the Blumer System Binder (a versatile connection system for rod-shaped large span wooden structures) was launched. Further fine-tuned over the next few years, CNC machines were introduced for precision drilling, while newer Computer Aided Engineering (CAE) programmes dealt with the statics and helped the drawing. That same year Blumer began, together with two other young engineers, their engineering company. Today, that same company, SJB Kempter Fitzke (the B is for Blumer) is responsible for the less specialised engineering on the Blumer related projects, including all the Shigeru Ban related work.
A year later, 1979, Blumer founded his own Blumer BSB company while also developing a customised window design and working on a new glulam structural system designed around box beams, made possible by high frequency gluing. The techno-fensters (or techno-windows) soon began production, turning into a separate company in 1995, and today Blumer Techno-Fenster is a sizeable operation, based a few miles from Waldstatt. For the glulam system Blumer turned to Professor Gehri, collaborating with ETH-Z’s timber department on tests of the extra-strength load-bearing glulam box beam. There were concerns around deformation and condensation, but as the lab tests continued these didn’t materialise, and the box beams passed the initial certification requirements. Designed to complement the BSB connection system, joined together the box beams provided the basis for a ceiling and roofing system which was titled Lignatur. The first Lignatur ceiling panels rolled off the manufacturing floor in 1984 to be used on a swimming pool roof designed by a St Gallen studio, Rausch, Ladner, Clerici, Schweiz Arkitekten (these days RLC Arkitekten) in a small town, Abtwil. From the photos it’s apparent that the Lignatur roof sits above BSB connectors, which are nothing if not large, constructed in pairs of giant trusses and spanning over 100 metres. R&D into the box beam elements continued; one focus was on improving the soundproofing acoustic properties of load-bearing Lignatur panels, and in 1997 Lignatur was set up as a separate company within in Blumer AG Waldstatt manufacturing facilities.
Machinery, the tools to facilitate Blumer’s experimental Lignatur panels, was another focus. Indeed, Christoph Meier, one of SJB’s timber engineers, notes that some of the companies began life primarily to test whether a particular piece of new computer tech would or wouldn’t do what Blumer & Co wanted it to do. Over the next two years, 1985-87, Blumer worked with Fritz Krüsi, a neighbouring Appenzell specialist timber machinery company, on developing the first five axis CNC-controlled machining centre with an automatic tool changer. With further work on a double-sided milling machine, the first production model, named Lignamatic was installed in 1989 at Krüsi’s Schönengrund factory, just a few kilometres south of Waldstatt. He also began to be involved in fire safety research just beginning at ETH-Z’s Structural Timber hub. During the year between, 1988, Blumer was also finding time to help Peter Zumthor with his small mountainside jewel, St Benedict Chapel.
The machine, and particularly its CNC capacity, threw open the doors on the spectrum of forms that could be machine-precision carved, planed and milled, from smallest to the extra-large, including for the first-time curved glulam, double curvature members and other complex three-dimensional forms. In the years since many other CNC machines have been developed, but back then the Lignamatic was the first working CNC joinery machine. “The beginning of a new world,” Blumer says today. There is also Blumer Elementtechnik AG, the glulam production and manufacturing company, originally sitting within the main Blumer company, before merging with Lehmann in 1997. Lehmann integrated and relaunched this aspect of their portfolio as Blumer-Lehmann AG in 2000, by which time Blumer himself had ceased to be involved.
With the Lignamatic machine operational there was the beginning of the technical capacity to manufacture the kinds of structural systems, the timber components and the joinery needed for free-form buildings. It wouldn’t be straight away, but eventually there would be a phone call: could Herr Blumer talk with Mr Ban, please?
In the early nineties, that phone call was still decade a way. Blumer’s skills were already in demand, though. He contributed to the engineering of architect Rolf Disch’s 1994 Heliotrope in Freiburg, the university town at the far end of south-west Germany. The idea of solar architecture had become increasingly popular, particularly across central Europe and Disch had taken solar to one logical conclusion, a building which turned to follow the sun; the Heliotrop’s solar panels were always on. Meanwhile, the same year, a young PhD student called Gerhard Schickhofer in Graz, Austria, was busy preparing to hand in his thesis on Cross- Laminated Timber.
There were further projects, including another giant sports arena in Luxembourg completed in 1999. In 2003 Blumer set up Creation Holz, the small bespoke timber engineering consultancy that he now heads up, moving his office the four kilometres from Waldstatt to Herisau. An early commission was a large timber sculpture by Herzog De Meuron bound for Jinhua, China. And then, just as HdM were deep into the build phase of their Beijing Olympic Bird’s Nest stadium, exporting Swiss construction expertise to China, another part of East Asia turned up on Blumer’s doorstep.
Shigeru Ban may not have been as far away: one of his three offices is in Paris, and the project was even nearer, in Metz, over the border in eastern France. But he had a problem. Arup, his engineers on the Metz Pompidou Centre, hadn't been able to resolve the structural workings of the multi-layered stacked timber blanket that Ban wanted to throw over the galleries and open heart of the building. Given Blumer's details by the German timber contractor, Holzbau Amann, Ban placed the call. Blumer did what he confidently says he'll do in these circumstances, committing to resolve the technical impasse, and did indeed come up with a workable solution for the meshed roof structure, rescuing Metz from possible oblivion. The beginning of a still active and ongoing partnership, Blumer has been Ban's favoured engineer ever since, playing a crucial role in the Japanese architect's emergence on the global scene over the last fifteen years, as he's populated cities and sites of the industrialised world with his stylised timber architectural signatures. Underlining the commercial significance, alongside Blumer himself, the engineer brought his sizeable network of colleagues and companies, machinery and Swiss timber technology expertise into the Ban projects, helping inject major international exposure and contracts for those involved. A big deal, no less, for the Swiss timber sector. Ban has returned the favour, describing the Swiss timber technology scene as "the most advanced worldwide."
It was in the year prior to Metz opening that I first contacted Blumer, arranging to visit his Herisau office in 2010. The interview was held in the side room of a ground floor office block. I was keen to discuss Metz, as I was fascinated by gridshell and related shell and free form structures and had already interviewed Ban. I wanted to get the engineer’s take. Blumer had invited one of the young project engineers, in part a linguistic go-between, as his English wasn’t particularly good, and neither, for that matter, was my German. I left with a rudimentary sense of the discussion, only to discover that my tape machine hadn’t been running. So that was that for a few years.
– Photo Hello Engineering! Magazine
Ban’s free form work extends and expands on the experiments in free form structures by the German engineer, Frei Ottoin the 1970s. Ban made multiple visits to Otto’s Stuttgart Institute of Lightweight Structures(ILS). The visits would eventually result in sharing credits for the Japanese cardboard gridshell pavilion at the Hannover Expo in 2000. Otto and ILS had already developed the 1975 Mannheim Multihalle gridshell, the first gridshell to be completed. During construction the woven lattice suffered eleven thousand plus of breakages. “A disaster” is how I recall Blumer describing it. What became clear at the meeting, though, was that Blumer was committed to lightweight timber shell structures and especially interested in what he called Bionic, what others term Biomorphic, and what has settled into the consensus ‘free form’ term.
Pompidou Metz propelled Blumer to international attention. Of equal significance for Blumer, and the Blumer-Lehmann partnership, though, was the Korean Haesley Nine Bridges Golf Clubprojects which involved the construction of an undulating glulam deck, punctuated with what, from above, looked like regular funnels, and at ground level revealed the first introduction to signature Ban’s tree-like columns. “That was one of the most difficult projects,” he has often said subsequently. Using similar hexagonal geometries to Metz, Haesley Bridge applies compression of the shell structure rather than the tensile properties of the French art museum structure. Beginning in 2007, Blumer didn’t at first have a firm sense of exactly how to proceed; at the same time he relished the challenge. “Ban gives you an idea and wants to see if it can work.” He likes to tell people, that he will always say that can find a solution even though much of the time he doesn’t have an answer. An answer does come, and he works at his computer developing a 3D structure before a further stage of checking if it’s viable through a pre-stats analysis.
After the abortive interview Blumer offered to give me a lift to St Gallen station, a few miles down from the rolling Herisau hills. This was his home turf, and he was heading to the Lehmann factory, as he was in the middle of partnering his timber construction with Lehmann. A few years later he’d step away completely, to concentrate on Creation Holz. I asked him what it was like to work with Ban, adding whether the Japanese architect was different to the two Swiss megastars for whom he’d provided specialist engineering advice, Herzog de Meuron and Peter Zumthor. “[Ban] is completely straight-forward and down to earth,” he replied, noting that “the other two are up in the clouds.”
I stayed in touch and in 2013 met Blumer again, this time at an exhibition at Zeughaus Teufen, a museum in Teufen, Appenzell’s home to Switzerland’s most famous engineering sons, the Grubenmann brothers (a major section in the museum is dedicated to the family). The exhibition was to honour and celebrate Blumer’s 70th birthday. There was the same hitch, however, conversation was lost in translation, and I struggled to get much from the time spent with him. This period was a new chapter for Blumer. Not only was he increasingly recognised for his international work with Ban, but the Japanese architect had also arrived in Switzerland itself. In Zurich, the Tamedia office building was newly opened, and with all-glass facades, the interior timber structure applying Blumer’s engineering was visible for anyone passing in the street. Ban had also been commissioned as part of a sweeping rebrand at Swatch, one of Switzerland’s best known watch companies. The company wanted a complete overhaul of their watchmaking site in the linguistic border town of Biel-Bienne – see the accompanying Swatch feature here – and Swatch had commissioned Ban to design three timber buildings, almost a complete campus. Two followed the structural hybrid timber-glass template that Tamedia had unveiled. The third was a free form structure, a long curving gridshell which eventually joins one of two main office blocks. These are more fully explored in the accompanying Ban features.
For these projects Ban had stipulated that the post and beam system were to be pure timber structures, without any steel screws, nodes or flitches. Blumer was tasked with coming up with a credible solution. Blumer notes he didn’t have any real idea at first, but experience had taught him that he’d find a solution. Indeed, it did. Waking at four in the morning the idea came to him to cut out a section of the spruce beam, reinforced with stronger beech hardwood peg and casing for the dowel space. “It’s in the middle of the night I have best ideas. It was burningly clear.” He compares the system he arrived at to that of a spindle he recalled in his father’s sawmill factory.
After this latest middle of the night moment, the statics and other engineering needed to be thoroughly tested and checked, Creation Holz and SJB Kempter Fitz sending over material to the go-to Zurich computation engineers, Design-to-Production, to crunch the numbers in their algorithms.
The template developed for Tamedia and the Omega and Swatch office buildings has been used again on Helen & Hard’s Stavanger Finanzpark, see this edition’s feature on the Helen & Hard project here with various individual differences. Swatch features two dowels, the Stavanger project four. Blumer is again working with the Stavanger studio, on a stripped back version of the office typology that Finanzpark initiated. Will the structural approach, though, establish itself as one of the main timber construction orthodoxies over the next years?
Ban’s challenge to arrive at a whole timber solution for Tamedia was close to Blumer’s heart. He is a hardwood believer, and is particularly interested in beech, which he is quick to note has hardly begun to be used. Through earlier years Blumer had developed what is described as a ‘depth hydro-phobatisation’ technique, in effect beech plywood with greatly reduced water absorption. Unsurprisingly he is ahead of the curve: Switzerland’s first engineered beech manufacturer, Fagus Suisse, opened in 2020 with one of Blumer’s long term inner circle and Creation Holz partner very involved. He shares this with his engineer peer, Professor Gehri, who worked through the 1980s and 90s on advancing engineered hardwoods, and on retiring immediately took up the main research role at neue Holzbau (n’H), the Jura company most closely identified with the development of engineered ash – see this edition’s engineered hardwoods feature here.
In the years after Tamedia was opened, the major Wood Resources research programme kicked off, with a strong focus on beech and involving Biel, ETH-Zurich and Wood Materials at Empa. By then Blumer was already giving presentations about Tamedia, where the outsize pegs featured beech inlays. At one 2014 conference in Basel, Blumer noted “how in engineering timber construction, beech wood with tailor-made wood-based materials, with ingenious material combinations and coordinated connection techniques, the quantum leap into a wood future that is still unimaginable for all of us is possible.”
In 2019, Pi, an 80 metre timber tower in the town of Zug, was announced. Though Blumer is not involved, it uses what, at least from the first PR renderings, looks like a strikingly similar double-façaded protective structure for its engineered glulam and Baubuche timber structure. Though too early to happen quite yet, Blumer is likely to feature and be quoted as a significant influence and reference point on the country’s tallest timber -and indeed on the country’s emerging engineered hardwoods development. That has long been identified as one of part of Blumer’s and his generational peers’ core agendas, illustrates his influence, and also, the time it takes from when one or a few people begin voicing a direction, to its eventual dissemination and broader uptake. It will also be very much part of Blumer’s wider legacy and influence on the return of Swiss timber engineering and construction culture. He has been instrumental in kick starting the countries increasingly enviable timber technology knowledge base, today, arguably, in Ban’s words, ‘the most advanced worldwide.’ As part of a generation that helped bridge the old concrete 20th century, and the emerging post millennial new world, Blumer has been instrumental in the Swiss-made return of timber over the last half century. The bridge to direct carpentry and forestry experience that Blumer represents may look back, but in the timber technologies’ reinvention he has quietly presided over, he has seen it is tuned to the 21st century, and the needs of its possible futures.
