David Churchill, a partner at Carter Jonas, asks how much Green Belt must local authorities release to meet housing targets.

In a meeting of the Housing, Communities and Local Government Committee in late November, housing minister Matthew Pennycook admitted to MPs that meeting the Government’s commitment to deliver 1.5 million new additional homes over this Parliament was going to be ‘more difficult than we expected’. The fact that fewer than 200,000 new homes are set to be built this year is an indication of the challenges ahead.

For many years the Green Belt was central to the debate about the housing crisis and the current Government is beginning to turn words into actions by pledging to adopt a strategic approach to the use of Green Belt land as part of the delivery solution, including building on poor quality so-called ‘grey belt’ land.

In a recent report, Rethinking the Green Belt, Carter Jonas has moved the debate on a stage, by considering what land might be used and how it might be released.

Rhetoric surrounding the Green Belt is powerful and politically charged. Take for example the common claim that building on the Green Belt amounts to ‘concreting over the countryside’. While some Green Belts contain larger proportions of environmentally protected or publicly accessible land, there is also a significant amount of land with little environmental or amenity value – now coined the ‘Grey Belt’. This raises the question of whether it is necessary to protect so much land, and whether greater flexibility within the Green Belt would allow for better allocation of land.

The amount of land designated as Green Belt has recently increased: in the two years to April 2023, it rose by 25,443 ha (1.6%), returning Green Belt coverage to 2004 levels.

The Government’s commitment to building 1.5 million homes equates to 300,000 per annum over five years. Assuming an average plot size of 0.033 hectares, and even on the (highly unlikely) assumption that all of these homes would be built in the Green Belt, meeting this target would only equate to 3% of the current extent of Green Belt. The reality is that any Green Belt ‘land take’ will be far lower, with brownfield and non-Green Belt locations being prioritised. Hence the quantum of land to be removed from the Green Belt is likely to be pretty modest in the overall scheme of things.

Furthermore, our research shows the extent of Green Belt release required by region if housing stock was increased by 6% (to align with the 1.5 million housebuilding target, and again provided solely on the Green Belt): in London, a 6% increase in housing stock would require 21.1% of Green Belt land. In contrast, in five regions (South East, North West, North East, East of England, West Midlands, and Yorkshire and the Humber), a 6% increase in housing would equate to less than 3% of Green Belt land being released.

While this modelling is interesting, it is only theoretical. Of course we are not advocating all new homes being located on the Green Belt but are suggesting that there are strategic benefits in releasing some Green Belt land for housing. For example, this approach could reduce the number of ‘leapfrogging’ developments – those located further from urban areas than is desirable, which increase residents’ carbon footprints through extensive commutes and impacts on both businesses’ and residents’ proximity to urban centres.

There are several options to address the urgent need for housing, each with its own benefits.

For example, we have considered major transport routes running through Green Belt land which present potential for sustainable development and prevent both ‘leapfrogging’ and urban sprawl. This showed considerable potential: for example, no fewer than 60% of the junctions on the A40 fall within the Green Belt. Greater leniency in developing in the Green Belt, particularly around these interchanges, would pave the way for much-needed residential and commercial development, while helping to shorten journey times and reduce congestion.

The modest release of land from the Green Belt, perhaps through edge-of-town development or development along major transport arteries is part of this solution. Selecting sites of lower environmental value which are not designated for conservation would ensure that the impact on the natural environment is minimised.

The reality is that any Green Belt ‘land take’ to meet housing need will be far lower than the figures shown above, as brownfield and non-Green Belt locations would remain the focus of new housing, as the revised NPPF makes clear.

Building on the existing Green Belt will only ever be part of the solution. The Government has recognised this and the development of new towns alongside urban extensions and regeneration projects will also be an option for planners and developers. Raising the rate of housebuilding is a major challenge and a combination of all these approaches is necessary.