LONDON.-The Serpentine Gallery Pavilion 2009 is designed by Kazuyo Sejima and Ryue Nishizawa of leading Japanese architecture practice SANAA. The Pavilion, which is sponsored by NetJets Europe, opens on 12 July on the Serpentine Gallery’s lawn where it will remain until 18 October.

Describing their structure the architects said: ‘The Pavilion is floating aluminium, drifting freely between the trees like smoke. The reflective canopy undulates across the site, expanding the park and sky. Its appearance changes according to the weather, allowing it to melt into the surroundings. It works as a field of activity with no walls, allowing uninterrupted view across the park and encouraging access from all sides. It is a sheltered extension of the park where people can read, relax and enjoy lovely summer days.’

Sejima and Nishizawa have created a stunning Pavilion that resembles a reflective cloud or a floating pool of water, sitting atop a series of delicate columns. The metal roof structure varies in height, wrapping itself around the trees in the park, reaching up towards the sky and sweeping down almost to the ground in various places. Open and ephemeral in structure, its reflective materials make it sit seamlessly within the natural environment, reflecting both the park and sky around it.

The Pavilion will be the architects’ first built structure in the UK and the ninth commission in the Gallery’s annual series of Pavilions, the world’s first and most ambitious architectural programme of its kind that annually gives preeminent architects their debut in this country and brings the best of contemporary architecture to London for everyone to enjoy.

There is no budget for the Serpentine Gallery Pavilion commission. It is paid for by sponsorship, sponsorship help-in-kind, and the sale of the finished structure through Knight Frank, which does not cover more than 40% of its cost. The Serpentine Gallery collaborates with a range of companies and individuals whose support makes it possible to realise the Pavilion.

Julia Peyton-Jones, Director, and Hans Ulrich Obrist, Co-Director, Serpentine Gallery, said: ‘Kazuyo Sejima and Ryue Nishizawa’s design embraces the parkland around the Serpentine Gallery as never before with an extraordinarily innovative design, which reveals the subtle play on light and perception so characteristic of their work. This Pavilion will be a wonderful addition to London’s landscape this summer. It is our dream come true.’

Separate areas within the Pavilion contain spaces for a café and an auditorium, where the Park Night events programme will be presented, including performances, talks, film screenings and the Serpentine Gallery Poetry Marathon.

Sejima and Nishizawa’s pioneering buildings have created an architecture that marries aesthetic simplicity with technical complexity, defining a new architectural language which plays with light and perception. Sought after by high-profile clients the world over, from the Louvre Museum in Lens, France, to the New Museum of Contemporary Art in New York, USA, SANAA’s projects are open stages which make visible the connection between the built structure, the users and the natural environment. Sejima, who in her early days studied at the Japan Women's University and worked with architect Toyo Ito, designer of the Serpentine Gallery Pavilion in 2002, began collaborating with Nishizawa in 1995. The architects are working with the structural design and engineering firm SAPS, led by Mutsuro Sasaki, and with the Arup team, led by David Glover and Ed Clark with Cecil Balmond, to realise this project.