The future sprawls before us — urban sprawl, that is. John Vidal of the UK Guardian says that in 50 years, we could see ‘vast “mega-regions” which may stretch hundreds of miles across countries and be home to more than 100 million people’.

In fact, they’re here already: the gargantuan Hong Kong-Shenhzen-Ghaungzhou conurbation, to take just one example, houses more than 120 million people.

Whether in-migration to these regions is a trickle or a flood (and the downturn has apparently had a mixed effect on migration to cities), the urban pull remains powerful, as the poor chase jobs and escape degraded rural environments or conflict.

Costly conurbations
The projection, from a new report by human settlements agency UN-Habitat unveiled at the World Urban Forum in Rio de Janeiro, Brazil, this week, points to sprawl as a symptom of dysfunctional cities — wasteful of land (including much-needed cropland), energy and resources generally and forcing up transport costs. 

(Ironically, Rio has its own significant challenges. Population pressures and poor planning there are pushing growing social unrest.)

Out-of-control development inevitably makes even less sense than usual in a slump. It’s just too costly, particularly if it leads to the building of porous, low-density infrastructure.

That cost might be buried in the wealth generated by these big urban engines (Vidal notes that just 25 cities account for over half the world’s wealth), but there is another, half-hidden issue that is socially costly: inequality.

Take Los Angeles, a city whose sprawl has gobbled up tract after tract of land and inspired a new term — ’Los Angelization’ — to describe the phenomenon. Here, an estimated 40,000 homeless people live ‘downtown’, miles away from the stratospheric wealth of Beverly Hills.

Similarly, the poor flooding into cities in the developing world may find themselves stuck in grim inner-city shantytowns, then driven out to be decanted into high-rise estates on the outskirts.

Chaotic or nonexistent planning can create ghettoes for rich and poor alike. The classes become physically as well as socially separated as ‘luxury’ complexes spring up here and there and the poor settle in what’s left.

High-density, high concept
It doesn’t have to be this way, as Pakistani architect, city planner and activist Arif Hasan has shown.

Hasan, an IIED Visiting Fellow, reveals in research (available as video, text, reports and a range of images on www.urbandensity.org) that small houses packed together can, with good design, be a sustainable choice on all counts.

As such they’re an antidote both to low-density sprawl, and the ‘iconic’ high-rises touted by developers and government officials eager to push Western planning models.

Small houses work for locals as long as they can be built up incrementally to a sensible height (‘ground plus three’). Hasan has shown that they can be even higher-density than regulations allow and still be sustainable — as high as 2280 people per hectare. (Just for comparison, Shenzhen’s average urban density is 1715pph.)

A flat-roofed house, as opposed to faceless apartments, tends to be an important factor for Karachiites. They might add on a ‘room at the top’ when someone in their extended family gets married — or just want a place to sleep under the stars on a hot night, or fly a kite.

Being able to add a room on also gives them a place for cottage industries or running a small business — key income-generating activities for the poor.

Given their relative cheapness and excellent ‘fit’ with the needs of poor and well-off alike, a compact, high-density solution looks like a brilliant counter-move to the ‘spreading miasma’ model of urban growth.

Small really can be beautiful: the future is high density.