Dutch Moment, Dutch Mountain

Hiring your engineered timber as a service, financial banks turning into material banks, flexible high-rise apartments you can refashion yourself, and architecture as land art. All these are wood and CLT related projects. Something is happening in the Netherlands with timber, though what it is exactly, and what happens next, is less certain.

“Right now, timber is really buzzing! You can really hear the buzz in architecture!” - the voice on the phone is coming from somewhere in Amsterdam, the Netherlands; the comment refers to a string of timber building making the headlines, plus CLT and the family of engineered timber which currently are having something of a moment in Holland. For instance, to name but three: there is Haut a 22 storey apartment block, the country’s contribution to the timber towers race. Also, ABN AMRO one of the largest Dutch banks, who have created CIRCL, a front of house ‘materials bank’ pavilion, with CLT and engineered timber as a quiet, though core backdrop. And, somewhere beside a motorway on the post-industrial outskirts of Eindhoven, the rather strange and surreal Dutch Mountain which – if the architect has his way, will use a sizeable chunk of CLT constructed from regional Brabant forest poplar.

Those are three headline projects, one going up, one complete and one waiting for planning – in that order. But timber isn’t the Dutch way, at least it hasn’t been, and ever since the industrial revolution, the Netherlands is, and has been a brick country. This flat, watery country doesn’t contain vast woodlands, and although there are - as in every European country, timber buildings they are old, the vast majority from pre-industrial times, and scarce. However, the need to meet the first hurdles of the Paris Climate Accord, has brought changes. Last year, the Government announced new wood plantings, aiming to increase wood cover from its low 11% current level, by a full quarter. Likewise, as these Dutch projects testify, the wave of interest shown in timber building is on the increase.

For Tom Frantzen - a young forty something architect, owner of the voice on the phone, the turnaround isn’t completely surprising. Ahead of the curve a decade ago and fortuitously or otherwise, he took up CLT in the late naughties. After a series of big efforts to win architectural competitions in the pre-recession mid-naughties but frustrated and disillusioned, he turned his attention to a building competition for developers which had come up on his radar. The competition was looking for an exemplar sustainable housing project in Amsterdam’s Buiksloterham dockland wastelands to the north of the city, itself in the earliest stages of regeneration. In 2007, Dutch mainstream sustainability orthodoxy, as elsewhere, was focused on energy efficiency and insulation. “I asked myself, ‘what could take the sustainability of the project further?’” he says. The answer was timber, and specifically, CLT.

From these initial seeds grew Patch 22, a 33 metre high housing block on the edge of the Johan van Hasselt canal. Frantzen, and his developer partner Claus Oussoren, won the competition on the strength of the energy and insulation programme, which includes an entire roof of PV’s, rainwater collection and reuse, and heat from CO2 neutral pellet stoves. But Frantzen also brought extra elements to the project; a CLT midrise building, a first, something which had never been tried in Holland before, and an approach to building that would add an unprecedented flexibility to the proposed apartments.

That said, the engineered timber spec changed during the design. “We started off with a lot of CLT” Frantzen says on the phone. “It was used to carry loads in the separating walls.” He wanted to make sure that the timber was a visible presence physically there in front of you, rather than hidden away behind plaster or some other material. However, working on fire risk, things took a trickier turn. The detailing required an extra layer of wood to meet the approved char rate: the time fire would take to burn through to the standard wood used in the building behind the additional layer. But Frantzen felt he couldn’t justify the CLT levels needed to maintain fire safety; there was just too much wood, and too expensive. A redesign began, with glulam beams replacing the CLT internally, though remaining on the two external side-walls. In the end, 195 m3 of CLT was applied to the non-glazed, east and west fronts; and for Frantzen, the CLT worked well when combined with the glulam. It is about “the atmospherics it creates.” Using glulam brought other advantages too, allowing for further flexibility to be designed into the apartments - which were taken up quickly.  Since Patch 22’s completion, Frantzen is in demand as a new role model in Dutch architecture - Patch 22 arriving in 2009 during the economic crash’s aftermath, when half the Dutch architectural profession went out of business.

Patch 22 has helped change the Dutch architectural mood concerning what, for many in the profession, regarded – and still regard - as an alien, unknown and unfamiliar material. “Patch 22 helped people see timber and CLT as a more regular material. Team V wouldn’t be building Haut without it” claims Frantzen, referring to Amsterdam’s timber high rise which will be entirely timber up to the eleventh floor.

“What we learnt after Patch 22, was that we needed to decide whether we were a timber architect or an architect developer who designs really flexible buildings. We decided we were the latter.” This decision informs the subsequent, Top Up project, which, if things go to plans, will sit next to Patch 22 by the end of 2019. Here, Frantzen says he was committed to another timber building where, unbeknownst to him, the municipality’s ground regulations had, in the interim, changed, with ground taxes twice that of when Patch 22 was under construction. The timber had therefore to be scaled back, with more concrete and steel turning Top-Up into more of hybrid building material-wise, including timber and timber-hybrid. “All the columns and outer façade will be timber,” he says optimistically, adding that the apartments have all sold. And, finally, he adds, they are looking at their third building, which “will definitely be a timber building.”

Frantzen’s use of engineered timber as a promotional tool resonates with other current showcasing, and Studio Marco Vermeulen’s Dutch Mountain too, is not short on self-promotion. Looking like something between a verdant double ended ski slope, and a beached sea creature, the building - which is split in the middle - rises at each end to provide seven stories of office space over the industrial and office landscape it is set within. With an artificial wetland, trees and a fruit orchard within the interior open space, the fact that the Dutch Mountain’s architect, Marco Vermeulen’s primary interest is landscape, indeed fusing landscape and architecture, isn’t perhaps a surprise.

Though aware of CLT, Vermeulen states that he really began to take the material on board when his neighbours, also architects, built their home from it. “It was amazing to see the building go up so quickly, in just a week.” Already part of the Dutch Mountain team, the studio soon integrated CLT into the design, and he says he then began to investigate how local woods could be turned into productive engineered timber. “In the Dutch/Belgian Brabant forests there is all this quick growing poplar, so we are talking to the forest farmers about how to start production of CLT.”

Sited on the outskirts of Eindhofen, this latest extension to a smart city post industrial park, Brainport, integrates office space and a hotel, emphasizing Vermeulen’s mixes - “a high tech context with a low tech tactile environment.” The design concept also shows off the of-the-moment ecological thinking, including furniture, food, heating and the buildings facade materials all coming as services, hired rather than bought.  This is very much current Cradle to Cradle and circular economy thinking, and though laced in PR puffery, the Dutch Mountain’s ambition is still provocative.

For Hans de Groot, long serving editor of Holland’s main timber building magazine, Het Houtblad, these projects underline how this ‘miracle wood’ is becoming accepted by the Dutch mainstream. “Even an architect like CIE is using CLT” he notes, referring to the corporate studio which has designed the ABN AMRO Banks CIRCL pavilion. CIRCL stands in front of ABN AMRO’s Gustav Mahlerplein Glass and steel HQ in Amsterdam’s Zuidas Financial district, and aims to highlight circular economy thinking, a core part of the country’s sustainability strategy: there are 16,000 pairs of jeans used as insulation, and the building is decked out with re-used furniture - both contributions to underlining ABN AMRO’s ‘materials bank’ ambitions. In the background, semi-mute but showcasing and sustaining the building of this banking enterprise, is the timber structure, comprised of CLT and glulam.

de Groot also points to HAUT, the Netherlands contribution to the timber towers race, as another sign that CLT is making real inroads into the Dutch scene.  HAUT is set to be the tallest timber building in Holland at 73 metres, and will include 55 apartments, when it’s completed in 2019. The 21-storey wooden residential tower will stand beside Amsterdam’s Amstel river and is desgned by Team V, along with Arup working on the structural engineering. The CLT will lock in about 3000 tonnes CO2. At its base an urban winter garden is being prepared to encourage HAUT’s residents to grow their own food, quite possibly a circular economy feature. While HAUT is part of the tall towers debate, as in other parts of the world, it feels like a distraction, compared to how CLT could be used on projects, which aren’t all about height and size.

One practice, which took up wood, including CLT early on, were SeARCH, who are, according to Frantzen, working on a CLT hotel. The early projects, probably the best known of which is their 2002-2004 Wolzak farmhouse and barn extension/replacement, deploy timber to showy, dramatic effect. For Wolzak, SeARCH exploded the barn, showing off a considerable part of its original frame timbers completely and becoming a key feature within the extension. Early massive timber wall panels are deployed in parts of the single floor build, along with stripped back bricks and a roof cut open with pitched glazing to let in the light. This was engineered timber as style accessory in the repertoire of natural materials. The studio repeated these tropes in more ambitious and, at the beginning of the next decade with their Favrholm Campus in Denmark a much larger and considerably more ambitious project. Again, CLT is a bit player, used in a visual ancillary rather than central role.

These SeARCH projects: Dutch Mountain, CIRCL and also Haut - use timber and CLT in the service of other concerns, whether a style statement, or current sustainability fashion. The material is entirely useful, though not necessarily technically, tectonically, materially, or tacitly interesting in itself. It’s no coincidence that the uptick in CLT comes at a moment when the Netherlands has embraced the circular economy big time. A Government led programme for the country’s economy to move towards becoming fully circular by 2050, was launched in September 2016, and includes the first milestone of cutting raw materials by half by 2030. While not wanting to sound sceptical, I can’t help but think that CIRCL and some of the other projects might not be around without circular economy being a Governmental priority. At the same time, the idiosyncratic ways timber has been used by SeARCH, points to its novelty. Without a timber tradition to speak of, there aren’t rules to follow. As Frantzen puts it, “there’s an individuality in Holland because of the absence of any tradition or general familiarity with engineered timber.”

To search out architects using CLT in ways that highlight the potential of the material and its particular design qualities, you need to take a step sideways; observe another architectural strand and one which predates the relatively recent take-up. Ask many Dutch architects about contemporary timber and they will point to a single project which sparked a first interest in the country; Parasites Las Palmas.

Parasites Las Palmas, a small lime green box sitting on the roof of the Palmas warehouse and a temporary structure, was visible for miles across the city’s industrial roofline, and a highlight in Rotterdam’s 2001 Capital of Culture. Designed by a young Rotterdam studio, KorteknieStuhlmacher Architecten, its impact on parts of the Dutch architectural scene were palpable. “It was very, very widely publicised,” says its architect, founder partner Mechthild Stuhlmacher, and influenced a small number of other studios to apply the prefabrication lessons imparted by the older wave of CLT interest, including SeARCH. “It was an intern who had been working here, who introduced CLT to SeARCH” Stuhlmacher relates – and to this, one should also add the MohnBouman practice. dRMM’s half-Dutch London architect, Alex de Rijke, see this Unstructured Extra’s dRMM special section - also saw the Parasite project and went away impressed, thinking about what the materials of the future might be.

Through being the first to use uncovered timber panels, Stuhlmacher can credibly claim to have single-handedly introduced solid wood to the Netherlands. Originally a small pavilion project initially bound for a Swedish housing expo, when the expo collapsed, Parasites was repurposed for Rotterdam’s Capital of Culture; then integrated into a set of small additive eco-projects, hanging, sticking and sitting on already existing buildings. Described more formally, as “prototypes for advanced, ready-made, amphibious, small-scale, individual, temporary, ecological houses,’ the programme was absorbed into the regeneration effort in Rotterdam’s run down Hoogvliet district.

KorteknieStuhlmacher, in the aftermath of the Parasite Los Palmas success, were keen to develop their engineered wood panel experience, and one CLT building after another has followed; so today, the studio can claim a broad portfolio of CLT projects, often combined with other timber materials. Starting with domestic architecture, in 2007 they completed De Kamers, a community culture house in Amersfoort, comprising a simple, differently scaled, set of boxes resulting in a sculptural, dynamic composition. There have since been schools built in Rotterdam, including an extension of Toermalijn primary school, the recent Schreuderschool special school for autistic children, and a new pavilion for Amsterdam’s Van Eesteren Museum.

Stuhlmacher was originally drawn to the material, she says, for “atmospheric and educational” reasons. “It widened our palate of materials, and prefabrication really helps. There is a unique combination of engineering, healthy living, craft and production. With CLT you have this direct contact with someone with knowledge. You can call them on the phone, and they can do the calculations, for the right length, height or width, there and then.” Since an early introduction to one of Merk’s carpentry team, Christian Dorschug, they have worked together on subsequent timber projects. Stuhlmacher, who is German, doesn’t care for the Dutch building industry, excoriating its philistine ways. There is, “a lack of craft, it isn’t appreciated by the industrial’ building culture.” It may be history, but illuminating the contrast is the cultural stand-off between the ultra showy Super-Dutch post-OMA studios; MVRDV, UN Studio, Mecanoo, practices which dominated the Rotterdam scene of the pre-millennial era, and, at the other end of the Rhine, the Swiss made craft of Peter Zumthor and the Swiss new materialists, and the rise of exquisitely crafted ‘Swiss Made’ buildings.  

Stuhlmacher acknowledges, that in the intervening years since Parasite, things have changed. “Now, anything goes.” We talk briefly about SeARCH, Frantzen, and the Haut high rise, which she acknowledges represents a timber culture; although again she notes how cost, and the bottom line, continue to rule. This said, what is also clear is that the CLT and timber network is small.  “It’s not become very big here.”

Stuhlmacher’s critique provides another rationale for why timber hasn’t been developed in ways where it has a more central role, even when used by large international practices. Pressed to think of new small practices who have embraced CLT, she cites Murmuur, a young and idiosyncratic Belgian studio, which lovingly crafted a shoe shop, Pelico, and its interior design, making for what looks like a poetic application of timber in a modest context, the very opposite to the attention grabbing pursuits of Dutch studios.

There are others exceptions, though you have to search for them. One is fellow Rotterdam practice, MohnBouman Architecten (until recently, reconstituted as Andrea Mohn Architects at the beginning of 2018) who have recently completed a sizeable social care project, Schiedam Care Campus, which is at once, both mainstream, and depending on your perspective, more radical.

Their two phase Schiedam Care Campus for disabled adults, a one hectare site and  comprising two building phases, have preoccupied the practice since the beginning of the decade. The centre-piece is actually the landscaping. Rene Bouman, whose project it is, has cultivated a kind of architectural land art, using ‘extremely cheap’ sweet chestnut fencing poles as both a second skin and façade foil to personalise and soften what are orthogonal blocks which, with the second phase completed in 2017, face each other in the centre of the campus. It’s into this second phase that CLT has been integrated.

The first phase, a rebuild of the existing care centre, is where the chestnut fencing began, long snaking screens shadow the building’s outline, a strategy to counter, to quote Bouman, the ‘extremely introverted’ original building. The setting helps; the grounds are surrounded by trees and a pond-like ditch, separating the campus from the suburban housing beyond. With the new building, the chestnut fencing has been extended out and into the immediate surrounding grounds, running alongside the main paths around, into and through the middle ground between the two buildings.

In plan, Care Campus 2 forms an E shape, each of the E’s three fingers facing the older building given over to single bedrooms and apartments for the more independent living. Divided into four core sections, 3000 m2of CLT - taking a back seat to the external expressive hybrid land art, is evident in the main reception corridor, as well as the stairwell and stairway. The material, using the same carpenter as KorteknieStuhlmacher, the Aichach based Holzbau Dörschug, is also plainly visible in the bedrooms and ground floor admin rooms. At the entrance, the British artist, Carol Fulton’s exploded large-scale photos of sweet chestnut woods, add to the atmosphere that has been created outside, and also are a thematic link to the previous photographic commission in the first building.   

As the building and its grounds settle into its place, the full hectare of grounds will turn into something akin to a public park. If tended with care, this building and land art project will show how the two strands can work and come together as one. In this, CLT, though a muted presence, works sympathetically with the wider aims, underlining once again its potential as a therapeutic, ‘healthy’ material.

MohnBouman’s Schiedam Care Campus programme suggests a more mainstream, if less glamorous future than the current swelter of showcase projects. Schiedam provides a CLT example in a more everyday context – which is needed if engineered timber in the Netherlands is going to move beyond the fashion statement and the show stopping. Such a future will depend on CLT becoming financially competitive, possibly brought on by tougher sustainability standards, embodied energy harnessed to the circular economy maybe. If the current wave of CLT and timber buildings continue to grow, it may signal that the Dutch drive towards the circular economy is building a head of steam; helping to recalibrate the economics of construction in ways which further favour wood. As it is, all those optimistic about the Dutch circular economy and its future would do well - in one of Europe’s Alpha-brickcentricas – to learn from this current woody moment, while it’s in the air.