Opinion – Peter Bishop and Richard Rogers

A city-wide public-space strategy will help London remain an open city, Richard Rogers and Peter Bishop say.

Public space has always been central to the political and social life of a city. Streets and squares are places for discussion and demonstrations, for formal and informal meetings. Public spaces by their essence are democratic places, where citizens have rights defined only by national laws. They are places to congregate and places for cities to define their character; to be generous and to show off. Erosion of public space, whether through loss of ownership or poor quality of design or maintenance, erodes the very fabric of society.

Public space should not be seen just as an amenity for urban areas, but as an essential element of urban infrastructure – part of the transport system, part of the ecosystem, part of the health service and – most importantly – part of the daily life of every citizen. And its importance has never been greater than in London today, as we hope to prove in Design for London's (DfL's) London Open City exhibition, which opens today (6 March) at Somerset House and will be followed in the summer by a public-realm strategy document.

It is possible to bring together landscape and movement strategies, and a current example of this is the East London Green Grid, promoted by DfL (AJ 13.12.07). In this project, green spaces are linked together to facilitate better connectivity and movement; to provide a robust design framework for the population growth in the Thames Gateway; and to connect the city with its green spaces and countryside.

London's urban development has not been a planned process. Relative peace and prosperity allowed London to grow outwards and dismantle its city defences earlier than most other European cities. It was able to absorb outlying villages and was selective about where it built, often leaving spaces untouched to create a low-density mosaic of buildings and green spaces. Royal patronage was superseded by the estates of the aristocracy and by the enlightened planning of the 19th and early 20th centuries, which invested in London's infrastructure and parks to create the framework we have inherited today.

One of the defining features of this process is that power has rarely been concentrated on a city-wide scale. Decisions to build and shape the city have been largely taken by individuals, privately funded, and negotiated and brokered with others. This negotiated urbanism gives London a pragmatism and dynamism and is alien to more formal approaches to planning.

This history of piecemeal development and absorption lends London's public spaces their almost infinite variety. London resists all attempts to define a single style of street, park or neighbourhood. The cityscape does, however, include some common features: terraced housing, small squares, and local centres. Uniformity and blandness of design are not options to be pursued in London. Great and lasting design solutions can often be very subtle and have a deep understanding of context and a sensitive use of materials. There are only so many icons a city can have before it becomes a theme park.

London's diversity has also been due to its citizens. As new populations have arrived, they have left their mark on London's public spaces – from Chinatown in the West End to the melas and cultural festivals that enliven many East London parks. The public spaces of an open city are continually adapting with their population. Their design needs to make space for their continuing evolution, not to hamper it by seeking to rigidly prescribe the uses that people will put places to.

The Mayor of London and the boroughs increasingly share a focus on the public realm and on the importance of creating and maintaining great public spaces at all levels, from amazing new parks – such as the Olympic Park in East London and Crystal Palace Park, for which German firm Latz + Partner is developing a masterplan – through to new landscapes in the Green Grid, new public squares, and better streets. The opening up of the South Bank, with projects such as Marks Barfield's London Eye, can be seen as one of the great successes of urban design of the last 10 years. The redesign of Trafalgar Square, completed by Foster + Partners in 2003 as part of the Mayor's World Squares for All programme, has shown that London can match the very best public spaces in Europe. Ambitious designs are under way for the redesign of Parliament Square, led by Hawkins\Brown; and Exhibition Road, by Dixon Jones, and developments such as Westfield's Stratford City and Argent's King's Cross will open up further opportunities for new public spaces.

London Open City was chosen as a title to reflect not only the importance of open space, but the very essence of London. An open city looks outwards to the world rather than inwards on itself. It is curious, willing to learn and welcomes new ideas and individuals who can contribute. The characteristic of an open city is the ability of people to settle there, become citizens and be rewarded for their contributions. In return, an open city takes on the character of its citizens and is never static.

In the exhibition, DfL will set out a series of interlinked proposals for London to become a more liveable city through improving the design of its streets, squares, parks and other open spaces. We will highlight some of the projects and programmes that will promote this vision, and discuss how public agencies, private companies and voluntary groups can work together to make these a reality. The ideas set out in the exhibition will be brought together in our public space strategy, which will be launched in the summer to coincide with the London Festival of Architecture.
London Open City will not be a blueprint for London; rather it should be seen as the beginning of a wider debate. We hope you will be joining us.

Richard Rogers is chairman and Peter Bishop is director of Design for London.

The London Open City exhibition runs from 6 March to 27 April at Somerset House, London WC2