Serpentine Pavilion by SANAA, Serpentine Gallery, Hyde Park, London, UK

By Rob Gregory

SANAA follow in the footsteps of Gehry, Eliasson and Thorsen, Koolhaas, Souto de Moura, Siza, Niemeyer, Ito, Libeskind and Hadid with their first UK commission at the Serpentine Gallery. Photography by Ludwig Abache

Question: what do you get if you cross 560m² of aluminium-clad plywood and some wood screws, 115 stainless steel columns and a concrete slab, all knocked into shape with a big rubber mallet? Answer: in the right hands, one of the Serpentine Gallery’s finest summer pavilions.

Every year, since Zaha Hadid’s triangulated marquee in 2000, Serpentine Gallery director Julia Peyton-Jones, co-director Hans Ulrich Obrist and their team have brought the work of overseas architects, who have never before completed a project in England, to the heart of London. The initiative demonstrates how vision, passion and determination can make a key contribution to our understanding of international contemporary architecture.

No architectural institution in the UK can match the quality and consistency of this form of curatorship. Architecture weeks and biennales come and go, providing great bursts of activity but producing little of real substance. The Serpentine Pavilion, however, offers the best of both worlds, while also providing a venue for a season of summer events. It brings a little piece of architects like Daniel Libeskind (2001), Toyo Ito (2002), Oscar Niemeyer (2003), Álvaro Siza and Eduardo Souto de Moura (2005), Rem Koolhaas (2006), Olafur Eliasson and Kjetil Thorsen (2007), Frank Gehry (2008), and now Japanese firm SANAA to a broad audience.

This summer, until 19 October, those unable to travel further afield are given the rare opportunity to experience the work of SANAA directors Kazuyo Sejima and Ryue Nishizawa first hand. Their pavilion is an exemplary collaborative work that maintains the clarity of their original concept - despite the realities of cost and time - and the pavilion’s curious double life. The project also reveals much about the architects’ attitude to architectural tectonics. All too often, Sejima and Nishizawa’s buildings are described as ‘ephemeral’, perpetuating a misconception that they have no real physical character. In reality, however, the work only exists through a robust understanding of technical issues. This enables spatial and social motivations to endure, whether building in Germany (AR April 2006), where precision is the industry standard, or in New York’s Bowery (AR April 2008), where SANAA’s project architect Toshihiro Oki noted how difficult it was to work with America’s relatively unsophisticated construction industry, in which one spanner (wrench) fits all.

Here in the centre of London’s Hyde Park, a unique series of challenges had to be faced, with funds, materials and professional consultation all given on a goodwill basis. ‘In many ways,’ says project architect Sam Chermayeff, ‘this is the most SANAA building of all, because it’s not really a building. Not just in terms of how the interior and exterior become one, but in the fact that there is no detail.’ The idea was to do as much possible with as little material as possible; the roof is very thin - ‘the thinner the better’ - and the columns equally so. Both architect and engineer Arup speak of the desire for a complete absence of detail. Where column hits ground and roof, and at the edge of the roof itself, the intention was always to have nothing; as Arup’s Ed Clarke says, ‘the engineering challenge is fairly evident, and while most of the time we could achieve nothing, the details where we couldn’t achieve nothing became the tricky ones, the ones that required the most work’.

Two days before the opening day on 12 July, Chermayeff expresses a fraction of disappointment.

‘The things that drive me nuts are that the columns are a little thicker than they need to be [with 60mm-diameter circular hollow sections augmenting the preferred 40mm section]. But we appreciate it’s not perfect. In fact, Nishizawa says he prefers it this way.’

Recalling the design process, it is remarkable that this is his only gripe, especially considering that Chermayeff, who led the project with colleague Lucy Styles, only visited London three times during the design and production stages. ‘The Serpentine called us to say, “you have the job”, on 8 February. And for several days we assumed that it was for 2010, as one would. But when we called back they said, “send us the design in four days”, which we didn’t. I mean, we had to spend more than four days working on this.’ But, in reality, not many more. Starting on site just eight weeks after that phone call (achieving planning consent in week nine on 19 May) the whole process was carried out at breakneck speed. It relied on the expert guidance of Peter Rogers, technical director at developer Stanhope, who described himself as ‘surrogate client’, browbeating all members of the team from designer to supplier. In addition, Philip Solomon, planning operations director at Mace, ensured momentum was maintained and obligations to NetJets (principal sponsor for the second consecutive year) and the pavilion’s anonymous future owner were met.

Each pavilion is demountable and handed over to a private buyer at the end of the summer season. SANAA’s pavilion was originally conceived as a solid sheet of welded aluminium, and almost everyone had an idea for how to make the double-curved roof demountable. With Mace pursuing clues from the aeronautical industry, Peter Rogers proposed a composite material that his company is using elsewhere, but eventually it was decided that the process of injecting foam into the aluminium wafer would have resulted in too much surface deformation. In the end, Arup proposed a plywood and aluminium composite, comprising two sheets of 3mm mirror-polished aluminium, bonded on to 19mm ply.

With the profile of the plywood cut into chamfered castellations that step in and out, each panel neatly interlocks. Theoretically, friction alone is strong enough to give the whole roof its integrity, but, as Chermayeff says mischievously, ‘only if they built it accurately enough’. He continues: ‘I still have a philosophical problem with it being a wooden structure. But there is something inherently funny about British architecture.’

Alluding to the ever-present legacy of Meccano and British high-tech, Chermayeff concludes with what he considers to be a predominantly British tendency, whereby ‘people seem obsessed with an architecture that is all about panellisation. In Japan, I am sure we would have welded the roof on site, cut it up and then re-welded it in its permanent location. The scars would have told the story.’ While happy with the results, you certainly get the impression that SANAA would do this project a little differently next time.