4 in 5 major residential appeals on grey belt land approved since policy launch

Our landmark analysis, supported by the Land, Planning and Development Federation (LPDF) – found that four in five major residential planning appeals on grey belt land have been approved since the government policy launched in December 2024.

The study examined all planning appeals referencing “grey belt” between 12 December 2024 and 31 August 2025.

It found that 80% (16 of 20) of major residential grey belt appeals – defined as schemes of 10 or more dwellings – were approved by the Planning Inspectorate. Across all residential grey belt appeals, 55% (34 of 63) were approved.

In total, around 1,600 new homes have been permitted at appeal on grey belt land in less than nine months – homes that, in many cases, could have been refused under previous Green Belt rules or taken more time to come forward. The average size of a residential grey belt appeal is around 30 dwellings, although the most common scheme size is one dwelling.

Overall, 57% (73 of 129) of all grey belt appeals – residential and non-residential – have been allowed, making the percentage of allowed appeals greater than those dismissed (covering hearings and inquiries only) in 2025.

Roland Brass, planning director, who led the analysis, said: “The data is clear – grey belt is a gamechanger. An 80% success rate for major residential appeals is unprecedented in the Green Belt context.

“The grey belt policy has not only opened up a new much-needed supply of land to help contribute towards addressing the housing crisis but it’s also giving developers and local authorities a more objective framework to work within.

“We’re already seeing the Planning Inspectorate, planning committees and officers becoming more confident in identifying and consenting grey belt schemes, which helps accelerate delivery in the coming years.”

The analysis also highlights the impact beyond housing. Residential schemes represented 73% of all grey belt appeals, with the remainder split across commercial (10%), industrial (9%), sui generis (6%), retail (1%) and leisure (1%). More than half (53%) of non-residential grey belt appeals have been allowed.

Regionally, the South East emerged as the key hotspot, accounting for more than half (52%) of the appeals, followed by the East of England (17%) and West Midlands (12%). The number of grey belt appeal decisions is also increasing over time, with July recording the highest volume overall (23) and August seeing the most major residential appeal decisions (5).

Roland said: “The fact that more than half of non-residential appeals are also being allowed demonstrates grey belt is not just unlocking opportunities for housing, but also for employment, commercial and community, infrastructure and energy uses.”

The report urges the government to take note of the success to date and demonstrates the positive power straightforward policy interventions can have on the planning system.

Roland added: “Grey belt policy has helped make the planning system faster, simpler and more certain, which is positive for all parties involved.”

The study provides pointers to anyone involved in grey belt assessment by identifying various specific and nuanced issues relating to very special circumstances, the purposes, towns and villages, and sustainability. It highlights that on the ground many sites utilise grey belt but it is the tests on appropriateness of development and golden rules that are more challenging.

The grey belt – introduced in the revised National Planning Policy Framework (NPPF) on 12 December 2024 – is a new planning designation that identifies lower-performing areas of Green Belt land, which can be released for development if it is not inappropriate development and meets the golden rules for community benefits.

Roland said: “The more objective approach towards the assessment of Green Belt land is massively welcomed. However, sites are still judged on a case by case so demonstrating a strong and evidenced grey belt case is crucial.

“It is important to remember that grey belt provides the window of opportunity but sites must still be sustainable and proposals still need to deliver benefits. Through the mandatory delivery of increased affordable housing, new infrastructure and accessible open space, new schemes are delivering benefits across the country while ensuring the vast majority and best parts of the Green Belt are protected.”

Nicole Burnett, senior policy and research manager at the Land, Planning and Development Federation, added: “We welcome the publication of this important research by Marrons, which highlights the positive and practical impact grey belt policy is already having on planning and housing delivery.

“The analysis provides clear evidence that more flexible approaches to land designation can unlock sustainable development in the right locations. However, while this is a step in the right direction, the government must go further – and act quickly – to deliver the wider planning reforms and fiscal incentives needed to tackle the housing crisis.”

Read and download the full report here.