There’s a hot word in the debate about the future of our cities: density. Cities, we are told, like middle-aged men, have a tendency to spread; they develop suburban love handles if you don’t keep tight control over their intake of housing and people. And when this happens you apparently get all sorts of problems.
Your infrastructure, like taut Y-front elastic, becomes dangerously stretched. People living on the periphery are no longer served by public transport so go everywhere by car, clogging up the urban centre and causing pollution to boot. Melbourne is a city that’s regularly cited as a metropolis that needs to watch its paunch. Sydney too.
Urbanists and city hall officials scared of becoming victims of sprawl use legislation and planning controls to try and turn the tide. This usually results in easing restrictions on the height of buildings in the hearts of cities – or at least a fierce debate about doing so. Look at London’s recent spate of oddly shaped skyscrapers. Even Zürich has decided that it is time to go up.
The other move is to restrict the growth of cities outwards. Since the 1950s London has had the Green Belt, a ring of restraining land on which it is almost impossible to get planning permission for new housing. The debate about density also sees architects coming up with ever smaller housing units and looking at how they can best make use of every scrap of their plot.
So you’d imagine that the result of all this action would be that our cities are becoming ever denser, busier and hummier in a nice, vibrant way.
Now let me introduce you to Dr Shlomo Angel author of the new book, Planet of Cities. Dr Angel, or Solly, is a bearded, 70-year-old professor who is quite happy to upset the consensus. I met him last week at the World Urban Forum in Naples and first encountered him after he had come off stage after slightly, and gently, undermining the vision of cities presented by a Chinese colleague.
Dr Angel has looked at the density of our cities and he’s discovered an odd thing. Despite all our efforts, our cities are becoming less dense. All those minuscule flats and fearsome rules have done bugger all. Dr Angel looked at US cities and found that average tract densities, to use the correct terminology, have been in decline for a century. Even Manhattan, despite adding all those skyscrapers, is less densely populated now than in 1910. Then he looked at 30 global cities and found that most of these had densities that peaked in 1910 too. And in many cities the rate of decline is speeding up.
Now obviously this throws up lots of questions (especially if you read all of Dr Angel’s book). But here are a few. Should we admit defeat and let cities spread? Are ideas such as the Green Belt outdated (they may not work and, even if they do, often have the unintended consequence of forcing up land and property prices in the core). And if now that cities are going to spread whatever you do, should we put aside the land now, build the basic infrastructure and embrace the process? Oh, and are all those bijoux apartments not even worth a footnote on an urbanist’s report?
Dr Angel is a man who doesn’t believe you can stand in the way of this cycle, although he seems optimistic that left alone market forces correct excesses. But in the meantime, there are a lot of mayors who should be ordering his book and deciding whether they need to start loving their spreading girth, wobbly bits and all.