Delight.

This year's London Architecture Biennale (the second) was a huge success, generating 75000 visitors to exhibitions, lectures, and installations from Borough Market south of the Thames, on a route north taking in Smithfield and Clerkenwell, and terminating at King's Cross. Widespread publicity was given to Renzo Piano and Richard Rogers driving a flock of sheep across Norman Foster's Wobbly Bridge, reminding us of pastoral and picturesque traditions in architecture, but other features were very much about the future.

The installation pictured here, 'London Oasis', was devised by architect Laurie Chetwood for a site outside his firm's office in Clerkenwell Green. It too attracted big publicity, was opened by London's deputy mayor, and intrigued the large contingent of visitors to The Crown public house immediately adjacent (Lenin used to drink there). The installation is intended to promote a revolution in thinking about how we use rather than abuse nawtural resources, and to demonstrate or symbolise some of the technology that could contribute to sustainable design thinking. Solar power is captured by cells in the wings of the structure, which also gather rainwater (recently in short supply); a wind turbine at the top of the mast transfers energy to batteries at the base; a hydrogen fuel cell provides energy for the 'oasis' by stripping electrons from the hydrogen present in methanol, giving a by-product of water vapour; the mast acts as a thermal chimney. The water collected is stored in irrigation tanks and transmitted to planters at regular intervals; air pipes running through water tanks result in cooled air being produced which is filtered and directed to users sitting in pods at the base of the mast. Information screens and lighting powered by the structure itself complete the project, which is at once a beacon for environmental design and an example of its implementation. And it looked wonderful at night.