Monthly Archives: May 2013

Danish density

Following the last post, I thought I should try to get some data on housing density in Copenhagen, which is widely taken as a model for urban development. From this paper by Jin Xue at Aalborg, I get a figure for habitable space in Copenhagen of 51 m2 per person. Interestingly, this is at a population density of 27.7 pers. / ha, which is relatively low. There’s further interesting commentary on Copenhagen’s housing model by Greg Bamford, Queensland, who supports the Danish approach, emphasising building separation and generous provision of usable semi-private / shared outdoor space.

British density

Britain is often described as crowded. London? Well, it seems stupid even to ask the question: of course it’s crowded. But I’d like to flip the question around. How much space can a person in Britain reasonably expect? And, for comparison, how much space does he or she actually have?

Some back of the envelope arithmetic. The UK has a land area of 243,610 km2. The population is 62.5M or so. That gives 3,900 m2 per person, or 0.39 ha. A decent amount. Of course, most people live in urbanised areas; let’s concede that this is desirable for economic reasons. So, how much space can a person living in a British town or city reasonably expect?

Leeds, my home town, has an area of 562 km2 and its population is around 750,000 (source). That gives 749 m2 per person (0.075 ha). But two thirds of this area is designated as green belt (ibid.). For now, let’s accept this planning designation: it curtails the area per person to 250 m2. That’s land area. Of course, we have the technology to build multi-storey structures on the land, potentially increasing the area per person. So there’s a multiplier: the plot ratio. Let’s assume, conservatively, that Leeds can be developed to a plot ratio of 2. This ratio can be taken to allow for open space such as roads and private gardens, and hence a typical structure might be 3-4 storeys. Sounds like a reasonable development goal? OK, then. A plot ratio of 2 gives us 500 m2 per person.

Now, how much area does a person living in Leeds actually have to swing a cat? This is a hard question to answer with elegance or precision, but here goes. Around half of the dwellings in Leeds are classified as having three bedrooms; this is the most common dwelling type (source). Take this as representative. The median gross internal area, for a three bedroom house in the UK, across all tenure types, is 92 m2 (source). If you take it that a three bedroom house in Leeds is lived in by three people (this might be conservative), then around 30 m2 per person looks plausible. So what happened to the other 470 m2? Is it all given over to employment use? Railway lines? Schools? Hospitals? Parks? Is it just wasted? Reserved for grouse shooting? It’s possible I’ve gotten my sums wrong, but I have to say I find this difference – between the space people could have and the space they actually have – just flat out boggling. Call it naivety if you like.

Coincidentally, when the LSE Cities project looked in detail at the Green Street East district of Newham, London, they found 27.8 m2 of habitable space per person, comparable to my (very rough) estimate of living space in Leeds (source). In the same study, the LSE project also looked at the Town district of Hammersmith and Fulham and found 49 m2 per person. However – and this is the interesting part – when measured in terms of persons per hectare, both districts had very similar densities: 176 pers. / ha in Green Street East versus 153 pers. / ha in Town. So in Town, Hammersmith & Fulham, for a given land area, more area is available to people. It’s also the wealthier district of the two. Conceivably, the provision of this extra space in Town is explained by a higher plot ratio, although not necessarily: the only firm conclusion I can draw is that this part of Hammersmith & Fulham just does better at land utilisation. Less land is wasted: more is converted – perhaps by building higher – to habitation. Which is what we want, right?

Update: On re-reading this, it occurs to me that a problem with the topic might be equivocation over the term ‘density’. Building taller increases built form density but doesn’t have to result in higher population density (and perhaps shouldn’t). A lot of UK discussion focusses on population density while glossing over the issue of habitable space. For example, Ed Glaeser:

We maximise our damage when we insist on living surrounded by greensward. Lower densities inevitably mean more travel, and that requires energy. While larger living spaces certainly do have their advantages, large suburban homes also consume much more energy. Anyone who believes that global warming is a real danger should see dense urban living as part of the solution.

This misses something important. Energy-intensive ‘sprawl’ is bad, yes, but people like living space; we should somehow try to arrange things so that they can have more of it.

UK self-build pioneers

Oliver Wainwright describes two group self-build schemes; one in Lancaster, another just outside Leeds. These two projects both emphasise building a sense of community, and have design features – such as a communal kitchen in Lancaster – to reinforce that. This might be a step too far for some, so it’s worth bearing in mind that you don’t have to sign up for everything good and holy just because you’re building as part of a baugruppe.



Compare and contrast. Chelsea Barracks, 5.2 ha. Sold for £959 million to a housing development consortium in 2007. Site remains empty. Woolwich Arsenal, 13 ha. Parcelled up and the best plots sold, from 2003 onwards, to housing developers such as Berkeley Homes and Barratt Homes. Large parts of the site remain undeveloped; enough for 5,000 (masterplanned) homes. Vauban, Freiburg, 38 ha. Sold, via an NGO, to a mix of private developers and baugruppen. Site is fully developed.

All of these sites were government sites (all were formerly defence sites). And while it’s arguable that the Chelsea site sale was ‘good value for the taxpayer’, there are good reasons for preferring the Vauban model over the Woolwich Arsenal model. With Vauban, the resulting development:

• Is democratic, and reflective of community needs and aspirations;
• Is socially well integrated;
• Has excellent energy performance;
• Conserves the best natural features, such as trees;
• Is interestingly diverse, being designed by or in close consultation with residents;
• Has safe, car-free residential streets (but with car ownership);
• Is popular: the entire site is now lived in.

Generally, the features of the Vauban Quarter were argued for, rather than imposed:

It was … meticulous liaison work with prospective residents that contributed to, and eventually built the necessary popular support for, some of Vauban’s most conspicuous innovations – such as the parking-free and carfree models of mobility management, the emergence of owner cooperatives (Baugruppen) as self-governed, non-profit developers and the instigation of building energy concepts far exceeding the already stringent legal requirements. Assisting people to translate their dreams and aspirations about sustainable living into feasible plans, and seeing them through a council planning department (that may be well-meaning in general terms but often sceptical in detail), became an invaluable role that Forum Vauban filled with verve, notwithstanding some inevitable conflict potential.

(Jan Scheuerer)

Of course if you look sympathetically at developments such as at Woolwich Arsenal, you can see some of the same planning ideas in play: there’s integrated public transport (the DLR extension) and developers are encouraged to create high quality public spaces, and to prioritise sustainability. But the dialogue between private for-profit developer and local authority, often antagonistic, is never going to much resemble the dialogue between future resident (and owner) and a non-profit development organisation like Forum Vauban. Developers have their own ideas about what appeals, and in Britain that often means a view of some water. In London, river front sites are strongly preferred, and are developed to very high densities. Meanwhile, other sites are neglected completely. Local authority planners struggle to give a humane shape to the outcome; often the result is very poor urban planning. Just try to take a walk along York Road, Wandsworth.

More about Vauban, Freiburg, here.

Community Build: baugruppen matchmakers

Community Build is a resource for matching people who want to join a baugruppe with projects, and projects with land. One project listed here is Slice London, a group of self-builders in East London: they were in the architectural press recently, and – as The Guardian reports – are interested in building on a former 2012 Olympics site. The LLDC (London Legacy Development Corporation) is mulling it over and inviting further expressions of interest. More on Slice London soon, I hope: it’s currently the only London baugruppe (that I know of).

Update: Look carefully, and you’ll see that the LLDC is being coy about what they might commit to. Probably the best thing they could do is just sell the land, blunting the price a bit: the group decides what to build (subject to planning and building regulations, obviously). But I’m worried that they’re thinking only that buyers get to tweak the layouts and outdoor spaces. If they start talking about ‘partnership with a developer’, run: that’s not what a baugruppe is about.