Designing Disorder. Richard Sennett
spaces would have attracted the anarchic Jane Jacobs.
But they were also sites which might have suited her organically focused temperament. These walls functioned much like cell membranes, both porous and resistant. That dual function of the membrane is, I believe, an important principle for visualising modern urban living forms. Whenever we construct a barrier, we must equally ensure the barrier is porous; the distinction between inside and outside has to be breachable, if not ambiguous.
The typical contemporary use of plate glass for walls doesn’t do this; true, on the street you see what’s inside the building, but you can’t touch, smell, or hear anything within; the plates are usually rigidly fixed so that there is only one, regulated, entrance within. The result is that nothing much develops on either side of these transparent walls: as in Mies van der Rohe’s Seagram Building in New York or Norman Foster’s new London City Hall, you have dead space on both sides of the wall; life in the building does not accumulate here. By contrast, nineteenth-century architect Louis Sullivan used much more primitive forms of plate glass more flexibly, as invitations to gather, to enter a building or to dwell at its edge; his plate glass panels function as porous walls. This contrast in plate glass design brings out one current failure of imagination in using a modern material so that it has a sociable effect.
The idea of a cellular wall, which is both resistant and porous, can be extended from single buildings to the zones at which the different communities of a city meet.
Borders
Ecologists like Stephen Jay Gould draw our attention to an important distinction in the natural world, that between boundaries and borders. The boundary is an edge where things end; the border is an edge where different groups interact. In natural ecologies, borders are the places where organisms become more inter-active, due to the meeting of different species or physical conditions. For instance, the shoreline of a lake, where the water meets solid land, is an active zone of exchange; here organisms find and feed off other organisms. The same is true of temperature layers within a lake: where layer meets layer defines the zone of most intense biological activity. Not surprisingly, it is also at the borderline where the work of natural selection is most intense, whereas the boundary is guarded territory, as established by prides of lions or packs of wolves. The boundary establishes closure, whereas the border functions more like a medieval wall. The border is a liminal space.
In the realm of human culture, territories consist similarly of boundaries and borders – in cities, most simply, there is a contrast between gated communities and complex, open streets. But the distinction cuts deeper in urban planning.
When we imagine where the life of a community is to be found, we usually look for it in the centre of a community; when we want to strengthen community life, we try to intensify life at the centre. The edge condition is seen to be more inert, and indeed modern planning practices, such as sealing the edges of communities with highways, create rigid boundaries lacking any porosity. But neglect of the edge condition – boundary thinking, if you like – means that exchange between different racial, ethnic, or class communities is diminished. By privileging the centre, we thus weaken the complex interactions necessary to join up the different human groups the city contains.
Let me give as an example a failure in my own planning practice. Some years ago, I was involved in a plan to create a market to serve the Hispanic community in Spanish Harlem in New York. This community, one of the poorest in the city, lies above 96th Street on Manhattan’s Upper East Side. Just below 96th Street, in an abrupt shift, lies one of the richest communities in the world, running from 96th down to 59th Street, comparable to Mayfair in London or the 7th Arrondissement in Paris. Accordingly, 96th Street itself could function either as a boundary or a border. We planners chose to locate La Marqueta in the very centre of Spanish Harlem, twenty blocks away, and to regard 96th Street as a dead edge where nothing much happens. We made the wrong decision. Had we located the market on 96th Street, we might have encouraged activity which brought the rich and the poor into some daily commercial contact. Wiser planners have since learned from our mistake and on the West Side of Manhattan sought to locate new community resources at the edges between communities, in order, as it were, to open the gates between different racial and economic collectivities. Our prioritisation of the centre proved isolating; their understanding of the value of the edge and border has proved integrating.
I don’t mean to paint a Panglossian picture of such ventures in planning: opening up borders means people of different strengths are exposed to competition. Borders can serve as tense rather than friendly sites of exchange – evoking some of the predatory quality of border conditions in natural ecologies. But taking that risk, which planners are now doing under more explosive conditions in Beirut and in Nicosia, is the only way, I believe, in which we can create conditions for a socially sustained collective life in cities; ultimately, isolation is not a true guarantor of civil order.
The porous wall and the edge as border create essential physical elements for an open system in cities. Both porous walls and borders create liminal space – that is, space at the limits of control, limits which permit the appearance of things, acts and persons unforeseen yet focused and sited. Biological psychologist Lionel Festinger once characterised such liminal spaces as defining the importance of ‘peripheral vision’; sociologically and in an urbanistic sense, these sites operate differently than those places which concentrate difference in a centre; on the horizon, at the periphery, at the border, differences stand out since one is aware one is crossing out of one territory into another.
Incomplete Form
This discussion of walls and borders leads logically to a second systemic characteristic of the open city: incomplete form. Incompleteness may seem the enemy of structure, but this is not the case. The designer needs to create physical forms of a particular sort that are ‘incomplete’ in a distinctive way.
When we design a street, for instance, so that buildings are set back from a street wall, the space left open in front is not truly public space; instead, the building has been withdrawn from the street. We know the practical consequences – people walking on a street tend to avoid these recessed spaces. It’s better planning if the building is brought forward, into an interplay with other buildings; though the building will become part of the urban fabric, some of its volumetric elements will now be incompletely disclosed. There is an incompleteness in the perception of the object.
Incompleteness of form extends to the very context of buildings themselves. In classical Rome, Hadrian’s Pantheon coexisted with the less distinguished buildings which surrounded it in the urban fabric, though Hadrian’s architects conceived the Pantheon as a self-referential object. We find the same coexistence in many other architectural monuments: St. Paul’s in London, the Rockefeller Center in New York, the Institut du monde arabe in Paris – all great works of architecture which stimulate building around them. It’s that stimulation, rather than the fact that the surrounding buildings are of lesser quality, which counts in urban terms: the existence of one building is sited in such a way that it encourages the growth of other development around it. And now the buildings acquire their specifically urban value by their relationship to each other – they become, in time, incomplete forms if considered alone, by themselves.
Incomplete form is most of all a kind of creative credo. In the plastic arts it is conveyed in sculpture purposely left unfinished; in poetry it is conveyed in, to use Wallace Steven’s phrase, the ‘engineering of the fragment’. Architect Peter Eisenman has sought to evoke something of the same credo in the term ‘light architecture’, meaning an architecture planned so that it can be added to or, more importantly, revised internally over time as the needs of habitation change.
This credo opposes the simple replacement of form which characterises the Brittle City, but it is a demanding opposition – a tension seen, for instance, when we try to convert office blocks to residential use.
Nonlinear Narratives
Cities do not build linearly over time: their shapes twist and turn as historical events alter the ways people live in them. But all too often, the ville is planned as though particular projects can be developed in a sequential fashion, moving from conception to completion with a minimum of alteration along the way. It’s certainly