This morning Transport for London announced it was getting into the housebuilding game. It’s releasing 300 acres of its extensive portfolio of land as sites for 10,000 new homes for the capital, not to mention assorted shops, offices and other commercial properties.

All this is tremendously excited if you’re the sort of person who is excited by these things. Not only does it mean that a public body is finally doing its bit to provide London with some much needed homes: it’ll also generate a chunk of cash which TfL can then reinvest in its transport services.

The 300 spare acres included in this first wave are split between 75 sites, of which two-thirds are in zones one and two (“inner London”, to their friends). They include a train depot at St George’s Circus, just north of Elephant & Castle station; another at Parsons Green; and the sky above Bermondsey tube station, which at the moment is a bit on the low-rise side.

And these could be just the start. In all, TfL owns around 5,700 acres of land (just under 1.5 per cent of the capital). Not all of that will be available for development – TfL describes some of it as “part of the operational transport network” which, we imagine, means trains are running along it. But the statement TfL released today does make clear that those first 300 acres won’t be the last.


All this is so obviously brilliant news, that it seems churlish to say anything bad about it. But raining on everyone’s parade is basically my job, so here goes:

The numbers we’re talking about here are tiny. Really, really tiny.

TfL reckons it can put 10,000 homes on 300 acres. That’s about 1.2km2 of land, housing, let’s say, 20,000 people.  (That, incidentally, is a population density of around 16,474 people per km2, roughly three times higher than the London-wide average of 5,432 people per km2, a reflection of the fact it won’t included any parks.)

The population of London is expected to rise from 8.6m now to 10m by 2030. To keep up with demand, then, we need to be building homes for about 93,333 people a year.

In other words, 10,000 homes housing 20,000 people will meet demand for approximately 11 weeks.

While we’re doing these dismal sums, let’s imagine that TfL somehow finds a way to develop all its land to the same density. That’d create enough homes for around 380,000 people, which sounds like quite a lot. It’d meet demand for about four years.

In practice, most housing built in London over the next few years won’t be on TfL land – it’ll be nowhere near enough, of course, but it’ll be more than the 10,000 new homes TfL is talking about.

Nonetheless the point stands. This plan will help meet London’s housing need; it’ll generate money for London’s transport network without needing to raise fares. It’s good news.

But it’s not a solution to the city’s housing crisis. It isn’t even close.

Jonn Elledge is the editor of CityMetric. He tweets as @jonnelledge.