Recent appeals give colour to Grey Belt development uncertainty

Recent changes to the policy on Green Belt development in the National Planning Policy Framework (NPPF) have led to a string of decisions relating to schemes on grey belt land. Hermione Kemp and Matthew Tucker explore what the changes mean in practice and the implications of the decisions below.

Amendments to the NPPF

Revisions to the NPPF were published in December 2024 in order to support the Government’s pro-growth agenda. One of the changes introduced is the new concept of grey belt land which aims to identify and use specific areas within the green belt that are suitable for development, while ensuring the broader aims of green belt protection would not be compromised.

Green Belt designation is a long-established and well-understood designation over  land protected from development through policy, most usually located near to or between built up-areas. One fundamental aim of green belt policy is to prevent urban sprawl by keeping land permanently open. Essential characteristics of green belt land is its openness and permanence. 

The updated NPPF defines the ‘grey belt’ 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 relevant purposes at paragraph 143 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.

What is notable is that Green Belt purposes (c) and (e) (encroachment into the countryside and assisting in urban regeneration, by encouraging the recycling of derelict and other urban land) do not feature in this definition.

Once identified as grey belt, proposals still need to satisfy all the criterion listed in new paragraph 155 of the NPPF. Paragraph 155 introduces a further category of development which could be regarded as not inappropriate (i.e. able to be carried out). It specifies that the development of homes, commercial and other developments in the Green Belt will not be inappropriate where:

• the development would utilise grey belt land and would not fundamentally undermine the purposes (taken together) of the remaining Green Belt across the area of the plan. This means that purposes (c) and (e) come into play at this stage of the assessment;
• there is a demonstrable unmet need for that type of development proposed;
• the development will be in a sustainable location;
• the development meets the golden rules (where applicable).

A new footnote 55 confirms that harm to the green belt includes harm to its openness, but caveating that this does not apply in the context of previously developed land, or grey belt land where development is not inappropriate. 

If development cannot meet the criteria in paragraph 155 and is considered inappropriate, then the usual Green Belt restraint applies i.e. that development should only be approved if “very special circumstances” exist, as set out in paragraphs 153 and 160 NPPF. 

Because of these changes, there have been a number of recent successful appeal decisions whereby consent has been granted for development on grey belt land which was previously refused on the basis of being inappropriate development in the green belt due to the impact on purposes (c) and (e). We have summarised a number of these below. As these are recent decisions, it is worth noting that they may still be subject to challenge, but that the general principles identified will remain relevant.

Grey belt decisions

Battery energy storage facility– Appeal ref APP/V4630/W/24/3347424

Planning permission was originally refused for the construction of a temporary 49.35MW battery energy storage facility (BESF) in the green belt by Walsall Metropolitan Borough Council. In August 2024 the parties had agreed, having regard to the NPPF at that time, that the proposal comprised inappropriate development in the green belt in Walsall.

Due to the recent changes to the NPPF, the issue of whether the development was inappropriate needed to be readdressed. 

On appeal, the Inspector considered that the proposed development site was grey belt land, after finding that it did not contribute strongly to green belt purposes (a) and (b) and that purpose (d) was not relevant to the proposal. 

For the proposal to be considered as not inappropriate development, it still had to satisfy the criteria listed in NPPF paragraph 155. The inspector was satisfied that these were met (criterion (d) did not apply), finding: 

1. While there would be some harm to encroachment (purpose (c)), it would be negligible considering the relative scale of the proposed development site within the green belt area. Further, the alternative site assessment concluded that there was no other alternative site suitable for the scheme, therefore there would be no conflict with purpose (e). Overall, the development would not fundamentally undermine the purposes when taken together of the remaining Green Belt in the plan area.
2. Given the imperative of mitigating climate change and achieving net-zero, there was a demonstrable unmet need for the development proposed. 
3. The level of traffic for the proposed project would not be significant nor would it have an unacceptable effect on highway capacity or safety. As such, the development would be in a sustainable location. 

Based on those findings, the Inspector concluded that the relevant criteria contained in NPPF paragraph 155 were met and the development was not inappropriate development in the green belt. 

The appeal was allowed. In addition, the Inspector commented that even if the proposal's grey belt status were to be challenged, it would still be acceptable, as “very special circumstances” were present justifying the development's impact on the green belt. These included the great weight attached to the contribution to mitigating climate change and to energy security, the significant weight attached to the absence of alternative sites and the potential for permanent BNG, and the limited weight attached to the temporary economic benefits outweighing the minor adverse effects.

Additionally, the Inspector in this appeal noted that the NPPF contained some errors. On 7 February 2025, the NPPF was amended to correct cross-references from footnotes 7 and 8 and amend the end of the first sentence of paragraph 155. Footnote 7 was amended from "habitat sites (and those sites listed in paragraph 189)" to "habitat sites (and those sites listed in paragraph 194)". The reference to "paragraph 227" in footnote 8 was updated to refer to "paragraph 232". The first sentence of paragraph 155 was altered from "The development of homes, commercial and other development in the Green Belt should also not be regarded as inappropriate where:" to "The development of homes, commercial and other development in the Green Belt should also not be regarded as inappropriate where all the following apply:". 

The Government stated that the amendment to paragraph 155 was not intended to constitute a change to the policy set out in the NPPF and that the changes were to “correct cross-references from footnotes 7 and 8, and amend the end of the first sentence of paragraph 155 to make its intent clear”.

Solar farm and Battery Energy Storage System – Appeal Refs: APP/T3725/W/24/3347315 and APP/Q4625/W/24/3347316

These appeals were made against the decision to refuse planning permission for the construction of a solar farm and Battery Energy Storage System. Permission was originally refused due to the proposal being considered inappropriate development in the green belt, and that there were no other considerations which would amount to the “very special circumstances” required to clearly outweigh the harm by inappropriateness. 

The Inspector found that the proposed site did not contribute strongly to purposes (a), (b) or (d) in paragraph 143 and therefore the land fell within the definition of grey belt. The Inspector went on to consider the criteria in paragraph 155, particularly focussing on criterion (a). 

With respect to Green Belt purpose (c), the Inspector, differentiating this case from the appeal above, concluded that fields being largely covered by structures was manifest encroachment into the countryside and that that encroachment would be significant, particularly in relation to the solar array. The land, because of its extent, made a strong contribution to assisting in safeguarding the countryside from encroachment. The development would encroach upon an extensive tract of that land.

Overall, the Inspector found that the proposal would conflict with the purposes of including land within the Green Belt when those purposes were taken together because of the significance of the encroachment and the proposal amounted to inappropriate development. 

Despite this, the Inspector found that the “very special circumstances” required to justify the grant of planning permission had been demonstrated, and that the considerations in favour of the development clearly outweighed the harm to the green belt. The appeal was allowed. 

Housing and children's nursery on grey belt site - Appeal Ref: APP/H2265/W/24/3346228

Permission for 57 dwellings, a children’s nursery and pre-school was granted by an Inspector in the Kent green belt after the Council withdrew its objection to the scheme following the publication of the updated NPPF. The parties agreed that paragraph 154 of the NPPF did not apply but that paragraph 155 was engaged. In terms of the five purposes served by the Green Belt, the Inspector held that the site was enclosed on three sides by existing development, would not check the unrestricted sprawl of built up areas and did not play a significant role in stopping settlements merging. It would also meet the golden rules. As there was a proven need for the scheme and it was sustainably located on the edge of a rural service centre, the Inspector concluded having regard to paragraph 158, that permission should be granted.

Dwellings in the Green Belt - Appeal Refs: APP/R3650/W/24/3352222 and APP/M3645/W/24/3347328

These two appeals follow a similar trend. In the former, an Inspector granted permission for a dwelling and the latter for two replacement dwellings as although the schemes did not meet an established Green Belt policy exception for limited infilling, the appeal sites would not strongly contribute to purposes (a), (b), or (d) in paragraph 143 of the NPPF and could both be considered as grey belt land under the updated NPPF. The proposed developments were not major developments, and therefore the requirement of criterion (d) to satisfy the ‘Golden Rules’ was not applicable. 

Next steps and future of grey belt

It is important for developers and local planning authorities to carefully consider the impact these changes could have on schemes which have been refused in the green belt (to consider the merits of an appeal, fresh application or reapplication) as well as those in the early planning stages. 

In a written ministerial statement published on 31 January, planning minister Matthew Pennycook noted that guidance to assist authorities in assessing their Green Belt and identifying grey belt would be published in the coming weeks. It is also worth being aware that the House of Lords Built Environment Committee ran an inquiry into the grey belt and published a letter on 5 February 2025 to the Deputy Prime Minister. The letter concluded that grey belt policy had been implemented in a "somewhat rushed and incoherent manner" and that the Committee did not believe it was likely to have any significant or lasting impact on planning decision-making or on achieving the government's target of 1.5 million new homes by the end of the current Parliament. Concerns were also raised about the lack of definition for a “sustainable location”. It is not yet clear what impact this will have but it is likely that the definition and policy surrounding the introduction of grey belt land will come under further scrutiny later this year. 

Hermione Kemp is a solicitor and Matthew Tucker is a Senior Associate in Burges Salmon’s Planning & Compulsory Purchase team.