This reputation is about to be taken one step further. For a few evenings later this month, London will be transformed into a series of giant and temporary movie screens. The project, entitled Social Cinema, is just one of 180 or so events being held as part of the second London Architecture Biennale, which runs from Friday to June 25. Social Cinema is a collaboration between architects Peter Thomas and Catherine du Toit, and artists Neil Cummings and Marysia Lewandowska. The quartet will use various buildings to screen an eclectic mixture of films, including rarely seen lectures and documentaries from the archives of the Architectural Association, as well as depictions of the city in A Clockwork Orange, London Belongs to Me and The Ladykillers.

The locations are dotted along the main biennale route, which extends from Kings Cross in the north to Elephant and Castle south of the Thames. The first screening is on a car-wash wall in Clerkenwell on Saturday. On June 20, Social Cinema moves to Tower Hill for a show at Scoop in the More London development. This will feature work made at the Architectural Association during the past year, alongside older material from its film and photograph library. Other venues include the Finsbury Health Centre designed by Bernard Lubetkin (June 23) and Paul's Walk, underneath Norman Foster's Millennium Bridge (June 24).

In each instance, the entire site will form the movie theatre: the building doubles as the screen, surrounding steps as seating, houses mutate into projection booths, and un-built spaces become auditoriums. Each makeshift cinema will be installed and dismantled over two days, before moving on to the next venue.

A similarly imaginative fusion of cinema and city drives digital artists Andrew Stiff and Nina Noor. Their project, Temporal Facades, comprises six films shot along the Biennale route that they will then project onto the exterior of the Brewhouse Yard in Clerkenwell. According to the organisers, this installation will enrich and recontextualise the structure, 'where architecture and film meet at the juncture between the material and the ephemeral'.

Much the same thought is articulated with greater punch (not to mention clarity) by the biennale's slogan: 'Architecture takes to the streets'. For festival director Peter Murray, the mission statement isn't just a description, but a call to arms. 'The streets are where professional architects and the public can mingle and exchange views,' he says. 'Where the professional side of the debate can understand the views of the public.'

The debate in question concerns the very existence of London itself. Murray says that the city is undergoing its most profound period of transformation since the Victorian age. 'In order to make sense of the decisions being made about London's future, we need to understand the past. London

is different to a lot of other cities, particularly in Europe. In Paris, for example, a lot of new development takes place outside the historic quarters. In London, new development still honours a road plan that was really set in place by the Romans.'

The biennale offers a way, for architects and the public to come to terms with the capital's rapidly shifting skylines. Unlike the Victorians who, Murray says, 'just crashed through the existing environment', modern Londoners want to be consulted. Events such as Social Cinema are a chance for the public to consider their surroundings with fresh eyes and form their own opinions about the capital's future.

Facilitating this process is a vibrant and occasionally surreal-sounding programme of events. Foster - who will lead a sheep-drive over the Millennium Bridge in the biennale's opening event - will appear in rather more familiar guise when introducing a screening of Mirjam von Arx's Building the Gherkin, a documentary about London's latest skyscraper. The building recently loomed large in Basic Instinct 2, where it looked rather more excited by Sharon Stone than did David Morrissey.

Wheel, another film by von Arx, celebrates the wondrous London Eye, while pop group Saint Etienne anchors Finisterre and What Have You Done Today Mervyn Day?, pieces that explore less celebrated parts of the city. Mervyn Day, for instance, tracks the re-generation of the East End ahead of the 2012 Olympics.

Murray says he hopes the biennale will help unite London's diverse communities. 'The biennale is a way for people to interact with the city - to attract passers-by who might not be interested in architecture and get them caught up in it, get them involved and hopefully get them to join the debate.'