In an effort to speed the urban renaissance, London is in the midst of a binge of gap-filling. Every last piece of railway land, warehouse, bomb site and backlands patch is being turned over to town house and apartment building. There has been nothing like it since the '60s, and then it was a simple matter of 'knocking through'. Today's frenzy is more ambitious, and more difficult to explain.
Indeed the only convincing explanation comes from the US, in a book published 30 years ago.
In his study of the importance of energy flows in man-made and natural ecologies (Environment, Power and Society, Wiley 1971), the American systems analyst Howard Odum drew parallels between modern cities like London and 'concentrations of consumers' among seabed creatures such as oysters, clams and barnacles. Both types of 'urbanism', he saw, relied upon strong inflows to bring in energy and food, and strong outflows to dispose of heat and waste. From his studies of renewal and decay, Odum concluded that natural structures akin to human cities can only emerge where energy flows are highly concentrated and proportional to the size of the 'urban structure' to be maintained. Examples of 'connected associations of consumers' dependent upon strong energy flows were, he found, reefs of oysters and 'contiguous urban structuring in human cities'. Examples of 'unconnected associations' were plankton in the oceans, and 'estates of detached suburban housing'.
Odum's ecological perspective enabled him to see that spaces in a 'seabed city ' of shellfish are no more than gaps that have no practical function.
Indeed, in the seabed 'connected associations' that he studied, these gaps represented a risk to the whole city, much as bomb damage would do in a man-made city. In nature these gaps occurred by accident or ageing and were repaired by accretion into the surrounding mass, but this could only happen if enough of the structure remained undamaged.When gaps outweighed structure, repair grew proportionally more costly, time consuming and problematic.Too many gaps and the natural megastructure broke down and was lost.
If what we call public open space is no more than a gap in what should be a monolithic structure, and if such gaps only occur in nature as a result of senescence or damage, we could hypothesise that in urban terms, gaps or open spaces are really structural defects. There is some evidence for this since, as far as we can judge from history, medieval cities really were 'concentrations of consumers' without gaps. For example, Tehran, the ancient capital of Iran with a population of over a million, existed without public open spaces until the modernisation programme of Reza Shah in the 1930s, and other documented medieval cities retained public spaces only when fortifications were demolished, fires destroyed whole districts, or natural disasters befell them. In effect they were no more than gaps that could not be filled. The boulevards, vistas, parks and gardens that were subsequently laid out across these gaps were rationalised into the tenets of Renaissance urban planning, but only after the gap filling capability of the original megastructure had failed.
Thus from Howard Odum we learn that the building boom, reinforced by the zeal of the Urban Task Force, is in reality desperate gap-filling, driven by fear of the million gaps that suburbanisation of the outer metropolis has created. Deep down, all urban activists know that only a superhuman effort to recreate a car-less, space-less medieval megastructure - the original habitat of human 'concentrations of consumers' - can save the city from dissolution.
Stand firm! Compromise will only rationalise the inevitable.