Hybrid Hortus: not only timber
What’s up with Herzog & de Meuron? Stepping away from concrete convention the Basel starchitects are turning to a new hybrid earth-timber element system, while professing a new-found commitment to sustainability. But is it for real?
While waiting at the bus stop I began thinking about the Basel suburb of Allschwil changing its name to Atonement. It was high summer and the day had been hot and in the distance sounds of children laughing and playing drifted from the parkland swimming pool. It was not quite at heat wave red warning level, but in the glare of the sunshine, it was baking.
In Switzerland, as in other parts of Europe, the temperature is rising. During the hottest weeks of the year, thermometers consistently read nearly four degrees higher than 50 years ago. In Basel, on the hottest days, temperatures daily hit 35.8, again up over 3.5 degrees from a half century ago.
As with the rest of the continent, the upping of the climate ante has been playing out in the landlocked Alpine country, with the building sector no exception. For instance, waves of construction related R&D began a turn towards timber in the 2010s. Natural materials, re-use and the circular economy have also joined this agenda. Now, earth too, is getting its day, we could say, in the sun. At ETH Zürich, a major research project called Think Earth kicked off early in 2023 and has ballooned into a plethora of sub-projects. Roger Boltshauser, the Swiss architect most closely associated with the material – Further see the Roger Boltshauser and Haus Rauch feature – and already closely involved in the Think Earth programme, is finishing hybrid tall timber high rise, H1, in Regensdorf, close to Zürich, and part of the town’s Zwhatt development. At 75 metres H1 still uses concrete, but features an experimental rammed earth 12th floor, a significant step, say earth workers. There are also a number of small start-ups working with various aspects of the material, including Rematter, Oxara and Lehmag. The coup de grâce though, is a recently opened office building. Designed by the big brother of Swiss architecture, the project has been running for at least six years, and excitement growing around its reception and its impact on earth in construction projects. It’s called Hortus, the clunky abbreviation for the House of Research, Technology, Utopia and Sustainability. The big brother is of course Herzog & de Meuron Architects. And its site? Well, that’s close to the bus stop I was waiting at in downtown Allschwil.
Left – Switzerland Innovation Park Basel render graphic of the site – Senn right Photo Maris Mezulis/Herzog & de Meuron
On the side of the road, the Hortus site sits adjacent to other new office blocks in Switzerland’s Innovation Park Basel Area’s Main Campus. At its heart is another H&dM project, the Main Campus Building, a huge semi-circular courtyard lab and office block commissioned by Innovation Park’s developers, Senn, and further buildings are set to be built designed by H&dM. As far as Europe is concerned, Basel is Big Pharma Central. The list of companies with European headquarters in the city reads like a who’s who of the pharmaceutical industry, while two of the largest, Switzerland’s Novartis and Hoffmann-La Roche, have long been headquartered in the city. Over 800 Life Sciences and 400 Biotech companies are listed in the wider Basel area, alongside 30 research establishments. It’s no surprise that Senn’s Innovation Park is looking to attract science and pharmaceutical departments, alongside IT/new media, sustainability companies, research organisations, and start-ups to their campus. Johnson & Johnson and Roche Basilea subsidiary, Pharmaceutica, are already ensconced in the Main Campus building.
There’s also, though, another recent piece in Basel’s architectural-pharma chequerboard, the pRED Center. Brand new, Roche’s vast research campus overlooks the centre of the city from on high. Looking something like a medical white Shard on a bend in the Rhine, at 205 metres the tallest of the four vertical ziggurats dominates the skyline. Opening last year, Switzerland’s tallest building is also H&dM’s immediate local pharma predecessor to the Innovation Park. All that concrete to reach fifty floors, despite its green-scraper claims it must have blown the carbon budget sky high.
Compared to Roche’s high-rise district, the Innovation Park is in the suburbs. Allschwil,
close to the French border, cuts a far more everyday profile. At the other end
to the swimming pool, and opposite parkland and sports facilities, there’s a
jump cut from a hotch potch of smaller and older industrial units to a cleaner,
brighter streetscape of the up market, high end office and lab type buildings. Much is still
to built on, replacing what was once allotment fields, the land formerly owned by a
Burgerspital or medieval guild involved in welfare projects, social housing,
and care for disabled people. Follow the Innovation Park back along the streets
and it ends with another of H&dM’s buildings, Alba Haus, lining the
boundary. Across the border is a busy local Aldi, as Allschwil, the suburb,
resumes.
In between the row of high-end office and research buildings are swish, expansive, and at ground level, spacious and airy. Tucked between two buildings, including the vast Main Campus building, is the Hortus site. With a footprint of just under 3000m2, the five floors provide 14,000m2 of office space sitting on a 64m by 52m plot, enough for up to 600 workplaces. The design provides flexible space, including PLUG & PLAY, through the floors. In keeping with current office provision thinking, there are commercial zones, including kitchens, a work-out fitness studio, and on the ground floor a semi-public bar, café and individual offices. These facilities serve Hortus employees, but are also part of an effort to make parts of the building semi-public. To this end, further facilities including reading rooms are included.
Full five storeys high, alongside its Life-Science focus, Hortus is intended to be different: Not just another sustainability showcase, but pioneering and packed with state of sustainability tech, materials, and ideas pushing agendas several steps forward on a variety of fronts.
H&dM and the project’s engineers, ZPF, had been set a sustainability brief and benchmarks by the developer, Senn. But Alexander Franz, the young German architect in charge of H&dM’s studio team, notes that Senn did so without fully stipulating a programme. Senn outlined six core themes that the project needed to respond to and meet as effectively as possible. They wanted to ensure positive outcomes regarding business, energy, and resources, alongside designing a building which fulfilled both human and community dimensions. These five were joined by a biodiversity agenda for the inner courtyard and hanging garden. While there were benchmarks. For instance, under resources 15% re-use was required, and daylight, humidity, and temperature standards for the humancentric targets, Franz emphasises that he and his team felt they needed to be proactive. They took on the Swiss building code and its benchmarks, currently up to 2040, and specifically the recommended embodied carbon, and claim they’ve improved it by 10%. Regarding the energy outcome, the architect notes, Hortus will be energy positive within a generation.
However, the inner-courtyard is still very much present, with Dutch garden superstar, Piet Oudolf, who signed up to revamp a semi-public Japanese Garden after the initial landscaping company’s contract was not continued. Though designed to regulate the courtyard’s micro-climate, so far, the sprawling hanging garden of the early publicity renders has yet to grow at any scale. In time, hopefully it shall. Tech innovation there is a plenty. A 5000m2 plus PV system eating up sunlight to produce 66 kWh/m2 has been wrapped around facade as well sitting on the roof. The system generates an energy surplus, enough to balance out Hortus’s construction and operational life within 30 years. Another aspect of the design is natural ventilation, with revolving windows and double glazing which all respond to the daylight, humidity, acoustics and temperature requirements.
In planning and design since 2019, Hortus has, unsurprisingly, gone through several iterations. An early version envisaged a pond at the heart of the inner courtyard, but this was abandoned after the Swiss Tropical and Public Health Institute (SPT) provided a study of the future climate consequences of including . They then reported that within twenty years, a potential steep rise in both the species and levels of mosquitoes, was possible, if not likely. The pond proposal was dropped.
There is also no basement, reducing the building’s concrete footprint. In place, the ground floor is slightly suspended from the ground, doubling engineering-wise to ensure Hortus can withstand earthquakes. Aside from the foundations, there’s scant cement in the building. It’s also been designed for potential disassembly, contributing to a grid-like design and what Franz describes as ‘a tricky floor plan.’
Also new was the attention that H&dM and Senn have given to embodied energy. In an attempt to draw down the insulation footprint, H&dM brought in Switzerland’s straw specialist architect, Werner Schmidt, to see if using straw for insulation was an option. This was entirely new for Herzog & de Meuron, who ran the numbers on the top fifth floor by integrating straw bales into the walls. It reflected many architect’s newfound interest in exploring the embodied carbon of the façade. It didn’t, however, go anywhere.
What did, though, was the timber.
Photo David Walter
There is timber everywhere. Thin vertical columns rise between cross-braced structural glulam struts, lining each floor and stretching back across the expansive spaces. Some 3000m2 of wood was prepared by Blumer-Lehmann, the most adventurous of Switzerland’s larger timber manufacturing outfits, including milling 6000 beams. Senn’s sustainability agenda had underlined indigenous Swiss grown timber as a must, perhaps unsurprising given its rising priority just as the benchmarks were in preparation. The structural timber work beginning on site in September 2023. Blumer-Lehmann oversaw partnering with five sawmills and sourcing from 28 forests all from within the timber company’s home St Gallen canton, to deliver the timber. The supporting columns are beech hardwood, punctuating the floor space every 5.6 by 2.8 meters. Fagus Suisse, the hardwood start-up, supplied some 600m2 of their beech LVL. As it is, all the timber is SNB Swiss sustainable certified, the equivalent of FSC/PEFC certification
The timber also contributes to the office ambience, simpler and stripped down compared to more conventional office fit-outs, the wood’s warmth making work and rest spaces alike more inviting. For the H&dM team, transferring learning from the studio’s healthcare design experience into this new office context, helped considerably with the design.
Beechwood slender aesthetics – photo Maris Mezulis/Herzog & de Meuron
Photo Maris Mezulis/Herzog & de Meuron
Looking around, what is also clear is the absence of cross laminated timber. There are beechwood columns, glulam beams, and cross-bracing but scant CLT. With a 4.2m ceiling height on the ground floor, the posts are a dominant presence across the building’s office floors. The trickiness of the floorplan is partially due to factored-in design for deconstruction; the entire building is digitally audited to help with what feels a rather unlikely eventuality: disassembly. There are also other, more aesthetic touches. Franz and the H&dM team added a simple design element, shaving the exposed internal posts into elegant concave forms, which Franz calls, “a slender aesthetics”. It’s needed for the posts and cross-bracing, despite the wood’s warmth, interrupt and interfere with the office space’s open plan sensibility. The almost complete absence of CLT – though CLT was specified to line the lift walls – is most pronounced given the spans that could have been reached. But H&dM had another plan, which would help resolve the thermal mass required for the floor plan. What the post and beam pathway has brought is, according to Franz, a one-third carbon reduction on a CLT design. This different design strategy meant bringing in an old studio collaborator once again and an experimental system, that wasn’t Swiss.
Throughout the 2010’s, the Austrian rammed earth guru, Martin Rauch, has repeatedly discussed the prospect of scaling up rammed earth, applying industrial processes to one of the most ancient of materials and building traditions. “My part has not been to change the material. I wanted to change the tools,” Rauch said, when I visited his studio, regarding the tools, rather than changing the soil or their chemical composition. Rauch is as much an industrial inventor as he is an earth materials specialist. Lehm Ton Erde, his Vorarlberg-based company, had developed a production line facility and christened Roberta, a significant step in industrialising the process of manufacturing earth blocks. Already up and running since the early 2010’s, and integrating robotic control of the earth sifting, by 2020 Rauch and his team were ripe for scaling earth’s next chapter.
Rauch and H&dM have history, fine wines having helped with the introduction. The partner one hears so much less of, Pierre de Meuron, invited Rauch to restore his wine cellar using earth. Out of this came Lehm Ton Erde’s first at-scale project – the H&dM’s 2014 Ricola Herb Centre, with the Roberta machinery sent to an empty factory close to the site. Two years later Roberta was moved to Darmstadt, Germany, for Stuttgart’s haascookzemmrichSTUDIO2050’s new headquarters building for the organic food chain, Alnatura. Each featured rammed earth walls rising up to eighteen metres in height.
Photo Blumer-Lehmann
Lehm Ton Erde/Herzog & de Meuron
For Hortus, though, a different hybrid system was envisaged. Lehm Ton Erde had long considered various earth ceiling and wall elements, but there had never been a context to do the necessary research, testing and certification work needed. But with this new showcase H&dM and the Vorarlberg earth builders began talking about how to develop an earth-timber hybrid, given there were resources. A specific research path opened up, looking at ways to introduce robots into the manufacturing process, specifically filling hollow timber element slabs filled with earth, as part of preparing the ceiling elements. There was a rationale here. While timber structures can span sizable spaces, and tall timber reaches ever higher, concrete’s thermal mass brings built-in fire protection and heat storage, but also a hefty carbon footprint. The thermal mass could be kept, and the carbon footprint removed in a concrete free ceiling slab. Thermal mass’s other benefits would also be maintained, as well as storing moisture, and helping improve acoustics, ongoing problems with timber.
If hybrid earth-timber slab elements were introduced into Hortus, a host of Senn’s benchmarks would be met, from carbon footprint through natural materials, to acoustics and moisture control. As they pored over Senn’s plans for the sustainability showcase, for both developer and H&dM, the earth-timber hybrid was appealing, offering a new, exciting approach to the materials mix. But could it be done?
Lehm Ton Erde formally joined the design team during Covid’s summer months of 2020. Whether the hybrid slab was viable and ready within Hortus’s construction timeline was questionable, there was a regulatory jungle to get through. But in Switzerland, with more potential for realising R&D than the much of EU regulated Europe, early moves set the project in motion. Lehm Ton Erde began collaborating with an ETH Zürich start-up, Rob Technologies, and other partners, to see if robots could improve the manufacture process.
haascookzemmrichSTUDIO2025’s Alnatura headquarters in Darmstadt – photo Lehm Ton Erde
There were immediate challenges. The first was whether such a hybrid cassette would pass fire reg tests. Working with Blumer-Lehmann, Lehm Ton Erde built a two metre by four metre cassette container made up of spruce beams and clay vaults, weighing 2.6 tons, and transported it to Linz for fire testing. The test was successful and the research moved on to the next phase.
Rob Technologies began playing with a six axes ABB robot arm, tamping down and compacting the earth. By mid-summer 2021, Rob Technologies were demonstrating that their ABB arm significantly sped up production, reducing the ceiling element cost by up to a third. From this came a major five-year grant application but this wasn’t successful. Advancing the earth-timber hybrid was put on hold. Lehm Ton Erde waited, before around four months prior to the work needing to be scheduled a decision was made to switch to man-made cassettes and guaranteed to fit with the build schedule. Separately, the robotic Rob Technologies continued refining their prototypes, and three years later, launched their robotically produced earth-timber elements. One of Zürich’s new wave of earth materials start-ups, Rematter, had, with a commercial product under its belt, just arrived.
Meanwhile, though late, with the green light to proceed, Lehm Ton Erde and Blumer-Lehmann began organising the manufacturing – 810 hybrid earth-timber slab cassettes to be made in a field factory right next to the Hortus site. Earth dug a stone’s throw from the building site turned out to be particularly good quality. A sample was sent to Lehm Ton Erde. After testing, with Rauch delighted, observing how, “it’s fantastic earth”. The soils beneath the top humus layer were good to work with. There are three layers in all: a heavy clay layer, followed by gravelly loam, and beneath both a sandy gravel. Distributed equally almost three quarters of the used earth is from the site, the remaining marl is sourced from a relatively nearby regional supplier.
Lehm Ton Erde and Blumer-Lehmann worked in tandem to produce the cassette slab elements in the field factory, a group of tents on the stretch of wasteland beside the Hortus site. At about 5.4 metres long, the element’s solid spruce beams are longer than Blumer-Lehmann’s standard timbers, resulting in a mass of offcuts, used for facade battens and the window frames. Rauch declares the Hortus developed “wonderful machinery”, estimating Lehm Ton Erde’s input was around 50/60%. From there, human hands take over. A newly instituted filling machine spread the earth evenly into the elements of four individual bevelled trays or vaults. Around a dozen earth workers, supplemented at times, according to Franz, by enthusiastic architecture students, worked on preparing the earth in the four vault trays. They tampted and compacted the earth into the elements, before a forklift truck carried the slab to Blumer-Lehmann’s carpenters to complete the timber work, and seal and cover the earth trays. They are heavy things, the slab elements covered with three layered floor plates, each weighing 3.5 tonnes, before being craned up onto the building. Beginning in autumn 2023, at first six or seven cassette elements were produced each day, and quickly lifted onto the site. Blumer-Lehmann had between ten and twenty carpenters on site through summer 2023, guiding the crane to drop and manoeuvre the element slabs onto the support beams and posts, and then screw into place. Moving each element takes about twenty minutes. Once in place, the wooden strut bracing went up next, as the building took shape. The speed with which elements were being produced also improved, up from about thirty-five to forty-five a week. It was an involved construction process and Martin Mackowitz, Lehm Ton Erde’s man on the ground, acknowledges that the elements are more expensive, around 35% he says, but is also confident that costs will fall considerably before long.
Digging for earth – photos Hanno Mackowitz
Lining the earth vaults – photos Hanno Mackowitz
By the beginning of 2024, the 810 element slabs were part of the timber interior, two-tone stripes of earth and timber browns greeting early site visitors upturned eyes, the strips of compacted earth running back the lengths of each floor’s ceilings. By the time I visited later the same year, the floors were tidied and ready for presentation. Before my eyes were an eco-synthesis of two prime, intriguingly symbolic, natural building materials. Hermann Kaufmann, scion of Vorarlberg timber architects, speaks of earth as a good partner for wood. Franz, as he shows me round, is equally enthused. Along with H&dM’s entire suite of Innovation Park’s buildings, he seems to have embraced sustainability, and it’s been quite the learning experience. When I asked if another studio had pipped H&dM at the post by another project, Franz made it clear, it was critical for H&dM to be seen to be leading on the earth and timber hybrid, first adopters of this novel yet entirely ordinary material. Now it’s complete, how long before a next H&dM earth-timber building?
Photo Maris Mezulis/Herzog & de Meuron
HORTUS opened in June 2025 to considerable national and regional fanfare, particularly because of the hybrid ceiling elements. The sustainability credentials are rolled out and highlighted, although some aspects haven’t been as successful as others. Despite bringing in circular economy specialists In-Situ and Zirkular, Hortus hasn’t met its 15% re-used and recycled materials challenge . It looks from photos (I haven’t visited since opening) like the demonstration building it is, but a particularly flashy example, with the photovoltaic façade a main feature. Neither the structural timber nor the earth-timber elements make much external impression, though the slender beech posts stand within the wide foyer entrance the inner courtyard. On the earth-timber front, things seem to be going well. Between the first days on site and the opening, Blumer-Lehmann, Lehm Ton Erde and a third company, gbd, have launched Lehmit, to capitalise on Hortus and advance the new hybrid elements into this new chapter. What will unfold? Like so many other technical projects emerging from the German speaking sub-Alpine region, Lehmit follows in the footsteps of other timber tech innovation projects, whether Hermann Blumer’s serial timber technology developments, Timbatec’s super-CLT TS3.0 elements, or Kaufmann’s Bausysteme modules. At present, it isn’t any kind of rival to concrete, but it’s a signal of another material path, underlining what another of Rauch’s collaborators, Anna Heringer’s, says, “More earth, less concrete.”
The irony, though, is that Hortus is a timber minnow in a sea of concrete. Right next to Hortus is the centrepiece, the Main Campus building. At around four times the size, the Main Campus is semi-circular, with an open garden space in its interior, apparently equal to a football pitch. It is also all concrete. H&dM’s next building, the freakishly titled All, which will stand beside Hortus, is also concrete. So much for less concrete.
Herzog & de Meuron’s Main Campus building – photo Herzog & de Meuron
Franz at least appears relaxed about the concrete mire. After noting H&dM’s long tradition in timber buildings, these all contrast to the Main Campus brief, which was for a lab building and its need safe and stringent material considerations. Talking with Hochparterre’s Palle Petersen in 2022, Franz highlighted ventilation as an example, As a lab building the Main Campus requires a seven-fold change in air ventilation, compared to HORTUS’s 1.5. Wood in the lab context, Franz is adamant, is a non-starter. The design team worked to ensure structural elements like column grid and floor slab thickness were as efficient as possible. But add floor-to-floor triple glazing, building services to the concrete and, despite heating coming from non-fossil fuel sources, the building uses up a sizeable amount of energy. Franz also foregrounded the Main Campus’s economic dimension and what had been achieved within a tight budget, to show how comparable buildings to Hortus won’t get built unless they are cost-competitive. For Franz, like all those working commercially, economics always comes first. That economic health depends on ecological health, though, feels all but completely absent from the conversation. As it is, he also noted that that was then, and post-Hortus this is today, and things are rather different. Movement may be slow, but he seemed convinced construction, architects, and investors are moving in Hortus’s direction.
Senn is also using Hortus to inform their current work. It is a different world from when the Main Campus was commissioned. Despite Donald Trump and the return of Big Oil, ESG, and other largescale influences continue to push the corporate world towards building more sustainability.
Render of All, next in line at Innovation Park Basel – render Herzog & de Meuron
For Senn, Hortus was a risk the developers were prepared to take. Commissioned around the last time Climate Change hit the headlines, the pre-Covid era of burning forests and Greta Thunberg, and melting Glaciers and David Attenborough, Senn’s symbolic commitment comes across as laudable. But set against the backdrop of large buildings that shovel more fossil fuel-based materials, buildings, and carbon tonnes the way of the planet, the invitation to celebrate and admire withers somewhat. Hortus is described as ‘radical sustainability,’ which suggests, beyond marketing, a measure of serious intent. H&dM’s remaining All is billed as a fusion of Hortus and the Main Campus and is again packed with PV’s but is inevitably concrete, while aiming for Leed Platinum, SNBS Platinum, Minergie A certification. Things are vaguer for HOPE (House of Partnership & Engagement), designed by a young Basel practice, FelippiWyssen, and the final SPACE, due to round out the Innovation Park when completed, currently in 2029.
Buildings with labs and other pharmaceutical industry needs may be ecologically challenging. So maybe meeting these targets and building to current regulatory standards is quite enough. But if these assessment methods broader effectiveness, as some insist, are questionable, if buildings fall short of addressing what is needed to genuinely counter – rather than lag significantly behind – deepening climate breakdown, and if they don’t shift the dial on construction’s 40% carbon impact, surely asking whether this is real ‘radical sustainability’ is warranted. Senn may well be sincere in their effort but it can feel the wrong way round. To meet the future it’s easy to envisage the rigour embraced in Hortus needing to be the norm, rather than the exception.
Switzerland Innovation Center Basel complete – render Sen
Absent, also, from the discussion is that the Life Sciences are a major source of carbon emissions, between 4.5 and 5% of the planetary total. It differs and depends on where, and amidst Big Pharma, Biotech and the array of interconnected life science sectors of the green economy is quietly budding. This could be Hortus’s opportunity. Think of Green Chem, Eco-Pharmacopias, or Biomimetic Biotech – these are the kinds of sustainable start-ups Hortus is looking to attract to its office spaces. But in what feels like a characteristic disconnect of the post-industrial mainstream, nowhere, despite the blizzard of eco-data surrounding the project, could I find any discussion of how Hortus’s uses connects to the carbon footprint trajectory of the region’s Life-Sciences. Rather in Europe’s pharma-central, Basel, the Innovation Park is another piece of high-end Biotech real estate, a growth dominated third base to an incipient triangle so far dominated by Boston and Cambridge.
Photo Herzog & de Meuron
Not entirely dissimilarly, it’s quite difficult not to view Hortus as a bald attempt by Switzerland’s best-known architectural export to wrest back some credibility on the green front, after years of populating the planet with elegantly cool, yet entirely fossil fuel guzzling projects. One of the most jarring contrasts to Hortus is also one of H&dM’s most recent, the pRED Center Ziggurats. Still, an ageing giant trapped by its size, Basel’s favoured sons have been handed a petri dish of eco-research wonders to feast on, quite the opportunity for partial re-invention.
One can hope. “It was like winning the lottery,” Franz exclaimed during the building visit, recalling how much excitement Hortus garnered within the studio, especially among the younger generation. H&dM still hold huge sway across the architectural firmament, and the turn embodied in Hortus will influence the architectural world. Indeed, it led Franz to immerse himself in sustainability, before taking on the role as the office’s new sustainability head. Lessons and strategies learnt are integrated into H&dM’s working processes, and applied project by project and country by country. “There are regions where it’s more likely to be applicable, including home markets, Europe, and California.” After the traditional architectural distaste for the green building tradition, one senses Franz and the H&dM team were drawn into the implications and challenges of working with the different materials palette and design thinking to normal studio fare. How far it’ll genuinely be pursued is an open question, but with Hortus’s completion there is potential for a new in-house sustainable aesthetics to emerge out of the meeting between the studio’s past and this new prospective future.
As for Rauch and Lehm Ton Erde, they have added this new earth application to their CV, a good partner to timber. Hortus may well be the most successful realisation yet of Rauch’s decades-long attempts at scaling rammed earth. The Lehmit elements are the most persuasive example of the ‘radical sustainability’ rhetoric within Hortus, from which Lehm Ton Erde – and others – will learn. The Lehmit site declares that some 650 tonnes of carbon were saved with their use, but as there isn’t, as far as I could find, any simple stat on the buildings total footprint (rather H&dM provide kg/m2 figures), which is frustrating. None the less earth-timber elements seem sure to draw down buildings’ footprints if and as their use increases. And Lehm Ton Erde are, says Mackowitz, working on a series of earth-timber variants, including a hybrid wall element with Vorarlberg architects, Johannes Kaufmann & Partners for a project in Vienna, while in the region itself, lighting integrated earth-timber elements are being tested on a smaller domestic project.
The question remains: how to think about a project like Hortus? We are invited to admire and celebrate what is being called Switzerland’s greenest office. But surely without more concentrated, across the board efforts, rather than relatively small demonstrators within larger, more damaging built ecologies, projects like these are less likely to make a meaningful difference. Its most consequential contribution is the launch of hybrid Hortus’s earth-timber experiment. Perhaps that’s atonement enough. In the meantime, glaciers go on melting at exponential rates, forest fires increase, spreading yet more rapidly, and temperatures keep on rising. Yes, it’s hot out there, and it’s only getting hotter. ol
Further www.hortus.ch
www.herzogdemeuron/hortus
Hochparterre features on Hortus (in German) Unstructured 7 extra – Gone to Earth: Martin Rauch’s Swiss earthworks, including an in-depth Martin Rauch interview, Herzog & de Meuron’s Ricola Herb Centre, and : mlzd’s Swiss Ornithological Visitor Centre
Photo Maris Mezulis/Herzog & de Meurono