Dr Gabriel Ahlfeldt, an urban economics expert at the London School of Economics, says that building up with skyscrapers in cities like London is the only alternative to spreading out into the Green Belt.
London: on the up or down and out?
Such a position is typical of the tendency of economists to want to dichotomise debates about the Green Belt as all or nothing. But it is refreshing to hear one of them acknowledge that there are desirable development possibilities within the built-up area of cities, for a change.
Increasing residential and commercial density doesn't have to result in skyscrapers, though. In a way, skyscrapers are an admission of failure. We’ve planned our city badly, and the only way we can develop is to pile as much development as possible onto the only tiny parcel of land that is available – partly because the way in which land is traded in this country has made it so ridiculously expensive.
Given the low density at which the vast majority of London has been built, you could plan to meet growth needs by a slight increase in building height spread out across a wider area, which would also avoid the concentrations of impacts upon infrastructure that skyscrapers inevitably bring.
The average building in London is about 4 storeys high (13 metres or so). Increase that average to just five storeys (25% more) and you've found the space for another 2 million people and 200,000 businesses.
Before anyone baulks at five storeys, consider that Barcelona’s Eixample district is generally 6-7 storeys, and the building height restriction lifted in Paris in 2008 was 37 metres – which allowed for around 10 storeys. I’m forever hearing people saying how ugly Barcelona and Paris are, and how their built heritage has been ruined by all these nasty tall buildings getting in the way of the views of the Sagrada Familia and the Notre Dame. No, wait a minute, I’ve never heard anyone say that.
Not that there isn’t a place for skyscrapers in a world city like London - we just need to be more rational about how and where we develop them.
Of course, what you get when people develop on greenfield sites – usually miles away from the jobs the residents will ostensibly be working in and often badly connected to them, even if the homes are within walking distance of a train station (it won’t be the right train station) – they have recently tended to develop at very low densities: only around 26 homes per hectare according to the government’s Land Use Change Statistics, lower even than traditional suburban or ‘Garden City’ developments. This means that far more Green Belt gets developed than needs to be, and results in sprawl, which a recent report - from none other than the London School of Economics - calculated costs the US economy $1 trillion dollars every year.
The amount of Green Belt that needs to be developed is, of course, ideally none at all. But there I go, dichotomising the issue, just like an economist.
Find out more
Read the London faces skyscraper pressure unless planning laws change article on the London School of Economics website