The Serpentine Gallery's annual Pavilion is a staple of the capital's summer architecture calendar and it rarely disappoints. Combining space for events, a shelter from the summer sun, an oasis of relaxation and thought-provoking design, it has over the years taken the shape of a helium balloon, a super-bright red steel structure and a mysterious hidden garden. It is also always designed by an exceptional contemporary architect, one that has yet to complete their first built work in London, making this temporary structure a much-anticipated architectural happening.
In many respects this year's commission is special. To start with, the people behind it have actually already had a strong presence in London; albeit not as a team. Swiss practice Herzog & de Meuron are the architects of much-celebrated projects such as the Tate Modern conversion (and now, its addition), while their partner, Chinese artist Ai Weiwei, saw his hotly-discussed Sunflower Seeds show open at the Tate's Turbine Hall in 2010.
Herzog & de Meuron and Weiwei have worked together to great acclaim before on the Beijing National Stadium for the 2008 Olympic Games but this is their first collaborative UK venture. And it seems fitting that their new project should open just in time for the 2012 Games in London.
'Every year, architects impatiently and jealously wait for the announcement of the Pavilion,' said Jacques Herzog at the opening. 'Working with Ai Weiwei again makes it even more intriguing'. Meanwhile, Weiwei made his presence felt at the launch with a video statement. 'As an artist, I am always very interested to put art, design, architecture and social change together to make new possibilities,' he said.
Given the team's combined reputation for innovation and creativity, it is no surprise that they flipped the pavilion concept on its head. Instead of creating a fully-fledged new structure, the team's design puts the focus on the previous pavilions, in a near-archaeological fashion.
In a quest to 'uncover' the former pavilions' foundations, the ground was dug up to form a geography of patterns, low walls and steps that the visitors can explore - and sit on. The whole surface is covered in cork, enhancing the space's acoustics, as well as giving a tactile quality (and distinct aroma) to the interior. Above the excavation are 12 columns (one representing each pavilion, including the 2012 one) that support a large floating platform roof. It hovers 1.4m above ground and holds a shallow pool of rainwater.
Taking the visitor below ground level and within the intriguingly sculptural landscape of the excavation, Herzog & de Meuron and Weiwei's design acts as an homage to the Serpentine's whole Pavilion program, inviting the crowds to discover the hidden footprints of the new structure's predecessors.