“The plan-led system is, and must remain, the cornerstone of our planning system” Housing and Planning Minister Matthew Pennycook, 27 February 2025.  This article will look at grey belt in terms of plan making, utilising planning practice guidance “Advice on the role of the Green Belt in the planning system” (PPG), updated to align with the changes National Planning Policy Framework (NPPF) on 27 February.  Planning practice guidance sits alongside policy and informs it’s application.

Grey belt is described in the NPPF as, “for the purposes of plan-making and decision-making, ‘grey belt’ is defined as land in the Green Belt comprising previously developed land and/or any other land that, in either case, does not strongly contribute to any of purposes (a), (b), or (d) in paragraph 143. ‘Grey belt’ excludes land where the application of the policies relating to the areas or assets in footnote 7 (other than Green Belt) would provide a strong reason for refusing or restricting development.

The purposes which grey belt does not strongly contribute to, referred to in the description, are:

a) to check the unrestricted sprawl of large built-up areas;

b) to prevent neighbouring towns merging into one another;

d) to preserve the setting and special character of historic towns; and

Note, therefore, that the other purposes of the Green Belt: c) to assist in safeguarding the countryside from encroachment; and e) to assist in urban regeneration, by encouraging the recycling of derelict and other urban land, are not relevant to the definition of grey belt in the NPPF.  Land could strongly contribute to these purposes yet be grey belt.

The footnote referred to in the NPPF description of grey belt is a footnote to the section in the NPPF dealing with the presumption in favour of sustainable development (paragraph 11).  In summary, it requires strategic policies to provide for need unless other polices provide a strong reason for restriction – which is where the footnote comes in – or adverse impacts significantly outweigh benefits.  The footnote explains that the policies that apply are those in the NPPF relating to: habitats sites, and/or designated as Sites of Special Scientific Interest; Local Green Space, a National Landscape, a National Park (or within the Broads Authority) or defined as Heritage Coast; irreplaceable habitats; designated heritage assets; and areas at risk of flooding or coastal change.

The PPG sets out how the NPPF should be applied in relation to grey belt (and Green Belt).  Green Belt should be assessed in a way that is sufficiently granular to enable assessment of variable contributions to Green Belt purposes and to identify grey belt.  The PPG goes on to explain the considerations that inform judgments authorities need to make regarding the Green Belt.

In considering purpose a), unrestricted sprawl, the PPG directs that villages should not be considered “large built up areas” which could sprawl.  An area of Green Belt is to be considered to strongly serve the purpose if it is free of development and lack features that could contain future development.  It is also likely to be close to a large built up area and if developed result in an incongruous pattern, such as a finger of development into the Green Belt.  Conversely an area only weakly or does not serve the purpose if is not close to a large built up area or is close but contains or is largely enclosed by significant existing buildings.  Moderate falls between.

In relation to purpose b), preventing the merging of towns, the PPG again notes that villages are not included.  To strongly serve the purpose the area is likely to be free of development and form a substantial gap which if developed would likely result in the loss of visual separation between towns.  An area that contains features, for example a wooded area, might only serve a moderate purpose because the remainder of the area could be developed and the wood continue to provide visual separation.  An area serves a weak or no purpose if it is not between towns or is only a small element of a gap that provides no visual separation.

Guidance for purpose d) preserving the setting and special character or historic towns again points out that villages are not included and explains that an absence of historic towns in the area can make it unnecessary to assess against this purpose.  An area of Green Belt strongly contributes to the purpose if it is free of development, forms part of the setting for an historic town and makes a considerable contribution to it’s special character.

Any area of Green Belt affected by footnote 7 may require further investigation and could be designated grey belt provisionally in the interim.

After going through the process identified the authority can then draw conclusions about grey belt designation.  The PPG states, “any assessment area that is not judged to strongly contribute to any one of purposes a, b, or d can be identified as grey belt land, subject to the exclusion of land where the application of the policies relating to the areas or assets in footnote 7 to the NPPF (other than Green Belt) would provide a strong reason for refusing or restricting development”

However, there is a further check on grey belt designation, and any Green Belt release.  Authorities should consider whether, or the extent to which, the release or development of Green Belt would affect the ability of the remaining Green Belt to serve purposes a) to e) (not just those assessed in relation to grey belt designation) in a meaningful way.

There are estimates that 3% of the Green Belt could be grey (Green Belt covers around 13% of England) and that there could be 70,000 sites.  Wherever we end up, government is keen to get there quickly.  133 authorities have been given £70,000 to progress reviews of their Green Belt, the first step in plan-making for land currently designated Green Belt.