Anthony Breach: We should scrap anti-supply measures to increase brownfield development | Conservative Home

Anthony Breach is an associate director at Centre for Cities, where he leads on housing, planning and devolution.

If there’s one thing on which everybody in the planning reform debate can agree on – it’s brownfield-first.

While new homes on the green belt are still controversial, building more in urban areas is good for the economy and for the environment, and the high cost of housing in cities is a signal people are willing to pay for it.

Yet urban housebuilding is in serious trouble, with new starts in London falling to their lowest levels in years, in part prompting the Mayor of London’s push to release green belt land. What’s going on?

Although there are deep issues with England’s planning system that make urban development difficult, Centre for Cities has identified five recently-introduced “anti-supply measures” that have made things much worse. Each of these may sound sensible on the face of it, but each one struggles to achieve its stated goals; has unintended consequences; and is solved very differently abroad. A new approach for each anti-supply measure will help make brownfield development viable again.

The first of these is that the minimum space standard for new one-bed flats. Currently, the standard for one-beds for single households is set at 37m². This minimum is far above the average amount of space private renters can afford – 29 m² in England, and 25m² in London.

It is understandable that policy wants to increase space. But the effect of such large space standards is like setting the minimum wage above the average wage. Instead of increasing space for everyone, flats that are affordable to single people cannot be created, leaving them stuck in cramped houseshares.

If the space standard was instead set at 25m² or 18m², not only would family homes be released from houseshares back into family uses, but the purchasing power of single households would be released to support new housebuilding rather than stuck paying for high rents. In effect, it would be a demand-side policy that supported housebuilding and homeownership while decreasing prices – the Holy Grail of housing policy.

The second anti-supply measure is a series of overheating regulations. Climate change means Britain is getting hotter, yet policy in both London and nationally rules out air conditioning except as a last resort.

London’s overheating regulations now require large “notches” to be cut into external walls, with the aim of providing more windows and easier ventilation. This approach reduces living space yet also struggles to keep temperatures low in the hottest weather.

As these flats now have more windows, they also let more sunlight in. To reduce the heating effects from indoor daylight, national building regulations now also require new city flats to have tiny windows.

Allowing air conditioning as a way to comply with overheating regulations, like other countries, would solve both of these problems.

The third anti-supply measure is a new requirement for all buildings over 18 metres to have two staircases. After the Grenfell Tower fire, it is understandable that the public is concerned about safety and ease of evacuation from taller buildings. Yet Government research has shown that second staircases reduce evacuation times by only 6-13 per cent in 18-30 metre buildings and do not reduce the chance that people will be trapped, as staircases are already designed to be kept safe and clear of smoke in the event of a serious fire.

This negligible safety benefit comes at a high price. The loss of living space and costs of building a new staircase are why the Government’s impact assessment found that for £9 million of safety benefits the requirement would cost society £2.7 billion, with costs concentrated at the lowest heights. Ironically, 18 metres was not chosen for any reason related to fire safety, but with the aim of reducing costs by aligning with other fire safety measures that also kick in at 18 metres.

To fix the dual staircase issue, the Government could either revert to the originally-proposed limit of 30 metres for single staircase buildings, or the French height limit of 50 metres.

The fourth anti-supply measure is the Building Safety Regulator (BSR). Introduced in 2023, this new quango has absorbed all building control functions from local authorities for residential buildings taller than 18 metres, and introduced two new phases of sign-off – one before works could begin, and another before occupation can commence.

In practice, the BSR is blocking housing at a scale far beyond what was expected. In its first year of operation, the BSR only consented 14 per cent of the just over 1,000 applications passed the first phase of sign off, and just seven out of the 40 applications to the second phase of sign-off.

As local authority sign-off has been unaffected by this backlog, this seems to be a problem with the incentives of the BSR as a quango. While councils have housing targets to meet and residents to support, the BSR can adopt a ‘computer says no’ attitude with no repercussions.

To resolve this, the Government should push the BSR to grant more conditional approvals, and either increase the height limit for the BSR process to 30 or 50 metres, or scrap it and revert to local authority building control.

The fifth anti-supply measure is Biodiversity Net Gain (BNG). This system from 2023 now requires almost all development to provide or fund a 10 per cent increase in wildlife habitats, either on-site or off-site. In practice, this system hits derelict brownfield sites harder than cropland, as small urban sites often have little space for new greenery and former industrial wasteland is given a high “value” in the BNG system. The result is an incentive for suburban sprawl and a disincentive for urban regeneration, especially in cities with lower land values than London.

To fix the BNG problem, which is more burdensome than any system in peer countries, the Government either needs to rejig the value of all the credits to reduce the burden on brownfield land, or just scrap it for brownfield sites entirely.

Compounding all this is that these anti-supply measures affect each other. The ventilation rules are much more difficult to comply with in buildings with dual staircases, due to how they affect floorplans. BNG’s costs can be split out over denser and taller developments, but many builders are being forced to “chop” the height of their proposals below 18 metres just to avoid the BSR obstacle course.

The Labour Government will have to address all of these issues if they are serious about their housing agenda. Their target of 1.5 million new homes over the Parliament is composed of individual targets for each local authority, and it will remain completely out of reach so long as brownfield development in urban areas remains on ice.

The problem for Conservative policymaking is that despite a widespread desire for brownfield development, fulfilling this desire has been challenging. The anti-supply measures above were all introduced under the previous Government, which also tried to block development “out of character with the existing area” and individual brownfield schemes such as the Cockfosters station development.

If the Conservatives are serious about brownfield-first, they need to call for reform of the five anti-supply measures. If not, they need to accept the only way to develop a coherent housing policy is with big releases of green belt land for new homes – there is no alternative.