So there is never a shortage of voices claiming that brownfield sites have a diminishing role to play in meeting housing need, and hence that more greenfield land should be released for development.
However, government figures released last week undermine that case. Information collected from English local authorities in 2010 shows that the amount of previously developed land considered to be suitable for housing development was 21 per cent higher than it had been in 2002, and that the estimated total housing capacity of brownfield land is 1.5 million, 69 per cent higher than it was eight years before. Clearly, the supply of formerly used land suitable for redevelopment is replenishing itself more readily than one might have imagined.
Brownfield sites certainly have an important role to play in meeting housing need. But it would be a big mistake to allow the new data to encourage an overconfident attitude to how much of the burden previously used land can bear in resolving the housing crisis.
Turning brownfield permissions and allocations into completions is not straightforward, particularly when developers have more profitable greenfield options to pursue. The government is already trying to enhance brownfield sites' attractiveness for developers by the use of local development orders and the creation of housing zones. But if it is to extract the maximum amount of completions from suitable brownfield sites, it should review whether an altered mix of incentives and penalties is needed to persuade developers to remediate more land and build out more brownfield permissions.
It also needs to ask why the proportion of councils providing brownfield data dropped from around 100 per cent to 50 per cent between 2010 and 2012. The fear must be that some hard-pressed town halls did not pass on the data simply because they no longer collect it. If such councils are no longer prospecting for brownfield sites as rigorously as before, there is a danger of unnecessary greenfield releases.
Every effort must be made to maximise the use of previously developed land. But this should not be at the expense of allocating adequate amounts of greenfield sites to meet housing need. Analysis of the government's raw data for 2012 shows that, although currently identified and suitable brownfield sites may be able to accommodate well over a million homes, 90 per cent of these have already been given permission or allocated in local plans.
By implication, the brownfield land currently available to planning authorities looking to make fresh housing allocations could only deliver about 100,000 homes. It's not an insignificant figure, and it will of course be gradually augmented as more previously developed land comes forward. But, at a time when new households are forming at a rate of more than 220,000 a year, it is nowhere near enough to meet need without large-scale greenfield releases alongside it.
Richard Garlick, editor, Planning firstname.lastname@example.org