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Grey Belt demystified: From green to grey

The introduction of grey belt policy marks a seismic shift in planning, moving from an automatic presumption against development to a framework where well-designed, sustainable proposals have a clear pathway to approval

7 March 2025
7 minutes read
Aerial view of agricultural fields with visible boundary lines and minimal vegetation, illustrating the concept of grey belt land. The image highlights areas of low environmental quality within the Green Belt, suitable for sustainable housing development as part of Labour’s grey belt plans to address the UK's housing crisis.

Did you know:

  • Over 100 planning appeals have cited grey belt land since December 2024?
  • Councils once opposed to development are now approving housing schemes on previously protected sites?
  • A single grey belt designation could unlock tens of thousands of homes in England’s most constrained areas?

In December 2024, the government introduced one of the most significant shifts in planning policy for a generation. A revised National Planning Policy Framework (NPPF) unveiled the grey belt — a new category within the Green Belt, designed to release land for development while safeguarding its core purpose.

Since then, planning decisions have started to shift. Refusals are being overturned. Developers are advancing schemes once thought unviable. And a growing number of councils are rethinking what Green Belt protection really means.

But what exactly is grey belt?

How do you know if your site qualifies?

And, most importantly, could this policy be the key to unlocking desperately needed housing?

This article sets out the answers. Backed by over 10 examples of approved and rejected grey belt developments, it shows how the policy is being interpreted and applied, and what that means for landowners, developers, and local authorities alike.

Let’s begin by unpacking exactly what grey belt land is and why it’s reframing the debate around untouchable land.

A satellite image illustrating the concept of Grey Belt land, showing a mix of previously developed sites, open green spaces, and woodland within the Green Belt. The image highlights how some areas, such as clusters of housing and commercial buildings, may be classified as Grey Belt due to their limited contribution to Green Belt purposes, making them suitable for potential redevelopment.

What is grey belt in planning terms?

Grey belt in planning refers to land within the Green Belt that is either previously developed or contributes only weakly to its core purposes. These areas typically offer limited value in preventing urban sprawl, keeping settlements separate, or preserving the character of historic towns, and may be considered suitable for sustainable development.

But where did this term come from and why does it matter now?

Recognising the need for targeted Green Belt reform, the grey belt designation was formally introduced in the new NPPF 2024, clarifying which parts of the Green Belt can be considered for development. According to the updated NPPF:

‘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.’

This shift hasn’t gone unnoticed. Since December 2024, over 100 planning appeals have cited grey belt, highlighting how it is quickly becoming a key factor in development approvals and a widely recognised opportunity among landowners and property developers.

What makes land grey belt?

Put simply, for land to be considered grey belt, it must be previously developed land and/or any other land that plays a minimal role in:

  • Preventing urban sprawl: The land does not act as a critical buffer against uncontrolled expansion. It may already be surrounded by development, enclosed by infrastructure, or lack the openness typically associated with the countryside.
  • Stopping neighbouring towns from merging: The site does not play a significant role in preventing towns from merging. It may be on the periphery of an urban area or its development would not erode meaningful gaps between distinct settlements.
  • Preserving the character of historic settlements: The land does not contribute to the setting, identity, or architectural significance of a historic town or village. It is not a defining landscape feature or an area that enhances local heritage.

However, grey belt does not include land that benefits from strong environmental protections or planning restrictions, where national policies provide a clear reason for restricting development. These include:

These designations override grey belt status, meaning that even if land meets the grey belt definition in terms of its contribution to Green Belt purposes, it cannot be considered suitable for development due to these overriding national planning constraints.

Grey belt status doesn’t mean guaranteed development - here is why

While grey belt designation removes some traditional barriers to development, it does not guarantee planning permission. Each proposal is assessed individually, with local planning authorities considering a range of factors to determine whether the development is appropriate. This includes the following factors:

  • Policy alignment and identified need:
    • Residential grey belt development must address a housing shortfall and align with the local plan.
    • Employment, commercial, or industrial grey belt development requires market studies proving a lack of suitable space.
    • Community facility grey belt development needs strategic assessments showing demand for schools, healthcare, or public services.
    • Mixed-use grey belt development must justify the balance of residential, employment, and community uses.
  • Infrastructure capacity and sustainability:
    • Housing grey belt development must have access to schools, healthcare, public transport, and local amenities to ensure it supports sustainable living.
    • Employment and commercial grey belt development requires freight access, workforce connectivity, and servicing capacity to function effectively.
    • Community facility grey belt development must be located where sufficient transport links and utilities can support public access and long-term viability.
    • All grey belt development should be in a sustainable location, with good transport, infrastructure, and amenities, ensuring minimal strain on local services and alignment with sustainable growth policies.
  • Community and environmental impact:
    • All grey belt development must preserve local character, biodiversity, and heritage assets.
    • Large-scale grey belt development may require mitigation for air quality, flood risk, or ecological impact.
    • Housing grey belt development should provide green spaces.
    • Commercial grey belt development must mitigate traffic and noise.
    • Community grey belt development should enhance social infrastructure without disrupting neighbourhoods.

Even if a site qualifies as grey belt, securing planning permission depends on meeting these planning requirements and demonstrating wider benefits that align with national and local policies.

Will your land benefit from the new grey belt criteria outlined in the February 2025 Green Belt Planning Practice Guidance (PPG) update?

On the 27th of February 2025, the government released an updated Green Belt Planning Practice Guidance (PPG), designed to help local authorities assess which developments should and shouldn’t be approved on Green Belt land, and to help them allocate grey belt land when forming local plans.

The updated PPG provides critical guidance on identifying, assessing, and unlocking grey belt land for development, setting a clearer direction for local authorities and developers. With the government under pressure to tackle the housing crisis while maintaining environmental protections, this guidance is already influencing planning decisions across England.

To keep things as simple as possible, we've rounded up the key updates you need to know.

A satellite image showing a mix of developed and undeveloped land, with roads and natural features forming boundaries. It illustrates how physical constraints can influence the assessment of unrestricted sprawl in the Green Belt.

Unrestricted sprawl further defined

As mentioned above, a key purpose of the Green Belt is to ‘check the unrestricted sprawl of large built-up areas.’

However, the PPG now clarifies that not all undeveloped land contributes equally to preventing sprawl. Instead, it defines sprawl as land where development would create an incongruous pattern - for example, an extended “finger” of development projecting into the Green Belt.

Furthermore, if a site is physically constrained by features such as topography, rivers, or roads, or if it is partially enclosed by existing development in a way that does not result in an irregular expansion, the PPG suggests that the site does not significantly contribute to checking unrestricted sprawl and is, therefore, potentially suitable for development.

Interestingly, this clarification played a key role in a recent planning appeal in Beaconsfield, where an inspector dismissed a 120-home development, ruling that despite being surrounded by major roads, the site still served as an important barrier to urban sprawl

This decision highlights how grey belt classification remains subject to interpretation and will continue to be shaped by case law.

A satellite image illustrating the updated interpretation of Green Belt purpose b, which aims to prevent neighbouring towns from merging. The image highlights how suburban development interacts with open land, reinforcing the revised guidance that villages should not be treated as large built-up areas, thereby allowing for more balanced growth in smaller rural settlements.

Towns do not equate to villages

This update relates to purpose b, ‘to prevent neighbouring towns merging into one another.’ 

Historically, local councils have often included villages and hamlets alongside towns in their local plans. 

However, the updated guidance specifies that purpose b pertains exclusively to towns, explicitly stating that "villages should not be considered large built-up areas." 

Without question, this distinction is crucial, as many past Green Belt assessments classified land between villages as essential for preventing urban expansion, despite Green Belt policy originally being intended to curb the spread of large urban centres.

By clarifying this, the guidance reinforces that Green Belt protections should focus primarily on towns and cities, rather than unnecessarily restricting growth in smaller rural settlements.

Proving this, a St Albans housing development decision - which secured approval for 550 homes with community facilities on council-identified grey belt land - demonstrates precisely how this policy shift is reshaping planning outcomes across England.

More on this scheme a little later.

A satellite image illustrating the updated interpretation of purpose b in Green Belt policy, which focuses on preventing the merger of towns rather than just reducing the physical distance between them. The image highlights how visual separation—through natural barriers, existing buildings, or topography—plays a key role in determining whether a site significantly contributes to maintaining distinct town identities.

Towns merging is not the same as towns getting closer together

If your site is located between two towns (not villages - specifically towns), that alone does not mean it plays a significant role in preventing their merger, even if development would reduce the physical distance between them.

The updated guidance on purpose b makes this clear. First, a site only has a strong relevance to purpose b if it forms a substantial part of the gap between towns. But even then, what truly matters is visual separation - how people perceive the towns' distinctiveness, rather than just their physical proximity.

In essence, this means that if a development site is shielded from view by existing buildings, dense woodland, or significant changes in topography, then it may not be considered as strongly contributing to preventing the merger of towns.

If your land is not inappropriate development then there is no Green Belt harm

According to the PPG, “if development is considered to be not inappropriate development on previously developed land or grey belt, then this is excluded from the policy requirement to give substantial weight to any harm to the Green Belt, including to its openness.”

In simple terms, this means that if your proposed development is not classified as "inappropriate" under Green Belt rules - such as certain types of development on previously developed land or in the grey belt - then it is not considered harmful to the Green Belt. 

Normally, any harm to the Green Belt must be given "substantial weight" in planning decisions, but the PPG clarifies that this does not apply if the development falls within the exceptions mentioned. 

At its core, this represents a fundamental shift in how Green Belt harm is assessed. Previously, any development in the Green Belt required 'very special circumstances' to be approved. Now, if a site is classified as grey belt, it does not need to pass that test, making the path to approval significantly more straightforward.

Essentially, if your project meets these criteria, Green Belt policies will not count it as causing harm, including any impact on openness.

This aligns with the Court of Appeal ruling in Lee Valley Regional Park Authority v Epping Forest District Council (2016), which confirmed that ‘appropriate development is deemed not harmful to the Green Belt.’ 

Worth noting, the PPG reinforces this legal precedent, making it clear that development on grey belt land does not require the same 'very special circumstances' justification as other Green Belt sites.

Individual sites assessed rather than wider strategic parcel

While a big part of the new PPG focuses on how councils should define land parcels when reviewing the Green Belt and grey belt for future local plans, this process will take time, and so applications and appeals for individual grey belt sites will continue in the meantime.

Right now, the key question isn’t whether some large, previously defined Green Belt area fits the new grey belt definition. Instead, the focus is on your specific site - the land in the application.

Bottom line: Does your site strongly contribute to Green Belt purposes A, B, or D? 

Remember, that's what matters - not the broader area it sits within.

Why Golden Rules matter for securing planning success

The Green Belt’s Golden Rules apply to all major residential sites proposed within the Green Belt, rather than being limited to major grey belt developments.

But here’s the interesting part: Golden Rules also influence the assessment of non-major developments, as the principles of sustainability, affordability, and infrastructure provision remain central to decision-making in the Green Belt. While non-major developments may not be subject to the full set of requirements, aligning with these principles can still strengthen a planning application.

The crucial factor at play here is this: If a development complies with these rules, it will be afforded “significant weight in favour of the grant of permission” under Paragraph 158 of the NPPF. This recognition reinforces the government’s commitment to delivering sustainable growth while maintaining the Green Belt’s essential functions.

Let’s look at a real example. A scheme in Kent provides a clear case of how compliance with the Golden Rules can influence planning outcomes. To meet these principles, the developer raised the affordable housing provision from 40% to 50%, a decisive move that played a key role in securing approval.

The takeaway? This adjustment demonstrates how incorporating higher levels of affordability, necessary infrastructure, and public benefits can significantly strengthen a planning application, particularly in areas where housing need is high.

The same principles apply to smaller-scale developments, where adherence to key sustainability and housing delivery objectives may enhance the case for approval, even if the site is not classified as a major development.

Key grey belt examples

When the grey belt policy was announced in December 2024 as part of the NPPF update, many questioned its potential for meaningful change.

Now, in a remarkably short time, its impact is already apparent.

Appeals reveal varied interpretations by different inspectors—some projects approved under the new framework, others refused.

Several significant planning decisions have emerged since introduction, providing insights into assessment criteria, successful arguments, and common refusal grounds.

The following case studies provide in-depth insights into key considerations and lessons from notable grey belt developments, highlighting the evolving interpretation of policy and the critical factors shaping application outcomes.

Let's examine how this policy works in practice.

1. Beaconsfield, Buckinghamshire - rejected development

  • Location: Beaconsfield, Buckinghamshire
  • Type of development: 120-home residential scheme
  • Key planning considerations:
    • Although enclosed by major roads, the site was found to contribute to preventing urban sprawl.
    • The Inspector determined that the site played a significant role in containing the spread of Beaconsfield.
    • Despite acknowledging a "dismal" housing supply, the Inspector concluded that this did not outweigh the harm to the Green Belt.
  • Outcome: Appeal dismissed
  • Key lesson: Even with a critically low housing supply, developments on Green Belt land may be refused if the site is deemed to play a strong role in fulfilling Green Belt purposes.

2. North-West Harpenden, St Albans - approved development

  • Location: North-West Harpenden, St Albans​
  • Type of development: 550-home residential scheme with community facilities
  • Key planning considerations:
    • The site was identified as grey belt under the updated NPPF 2024 criteria.
    • The scheme included 420 residential units and 130 retirement homes, along with a nursery for up to 110 children, two junior sports pitches with a pavilion, communal parks, allotments, and play areas, ensuring a diverse mix of housing and community amenities to meet local needs.The planning committee voted 5-4 in favour of the development on February 17, 2025, granting outline planning permission despite receiving over 1,800 public objections.Approval was largely influenced by St Albans’ critically low housing land supply (0.9 years) and the outdated 1994 local plan, making refusal difficult to justify.
    • Originally submitted in 2023, the scheme was updated to include social rented housing, increasing the affordable housing provision to 50% in line with the Golden Rules.
  • Outcome: Planning permission granted
  • Key lesson: When a site meets grey belt criteria and adheres to the Golden Rules, it can secure approval even in areas facing significant opposition and low housing land supply.

3. Bagshot, Surrey Heath - approved development

  • Location: Bagshot, Surrey Heath
  • Type of development: 135-home residential scheme (50% affordable)
  • Key planning considerations:
    • Site classified as grey belt under the updated NPPF 2024.
    • Council refused the application, but the inspector ruled in favour, applying the presumption in favour of sustainable development.
    • Recognised as a village, not a town, under Green Belt purpose (b), meaning its role in preventing settlement merging was limited.
    • No requirement to demonstrate 'very special circumstances' due to its grey belt designation.
  • Outcome: Planning permission granted
  • Key lesson: Grey belt classification under the updated NPPF can remove the need for ‘very special circumstances,’ making approval more likely where sites meet sustainable development criteria.

4. Tonbridge and Malling, Kent - approved development

  • Location: Tonbridge and Malling, Kent
  • Type of development: 57 homes, children’s nursery, and pre-school
  • Key planning considerations:
    • The 6-acre site is enclosed on three sides by existing development, minimising its impact on the surrounding Green Belt.
    • The development increased affordable housing from 40% to 50%, aligning with the Golden Rules for sustainable development.
    • Situated in a sustainable location with a proven need for housing and community facilities, including a purpose-built nursery and pre-school.
    • The developer increased affordable housing from 40% to 50%, aligning with national policy priorities.
    • The Planning Inspectorate granted approval after Tonbridge and Malling Borough Council withdrew its objection following the policy changes in December 2024.
    • The inspector determined that, since the site was enclosed on three sides by existing development, it did not significantly contribute to preventing urban sprawl or the merging of towns.
  • Outcome: Planning permission granted
  • Key lesson: Grey belt sites that are well-contained by existing development and adhere to the Golden Rules for affordable housing have a strong likelihood of approval.

5. Hertsmere, Hertfordshire - approved development

  • Location: Hertsmere, Hertfordshire
  • Type of development: AI data centre (Europe’s largest)
  • Key planning considerations:
    • The DC01UK proposal, initially submitted in September 2024, was assessed before grey belt policy was formally introduced but was later classified as grey belt under the updated NPPF 2024, allowing for development on previously developed land.
    • Located on an 85-acre site, the scheme retains 54% as open green space and delivers a 10% biodiversity net gain.
    • The Planning Inspectorate approved the project, citing its alignment with the government’s focus on investing in the AI sector and its role in advancing the UK’s position as an AI superpower.
    • The council supported the plans, noting that the data centre would deliver local economic benefits and enhance digital infrastructure while maintaining Green Belt protections.
    • The development includes a £2 million investment in local transport infrastructure, such as bus route upgrades and cycle hire expansions, and commits to a 10% net biodiversity gain by retaining over half of the 85-acre site as green, open space.
  • Outcome: Planning permission granted
  • Key lesson: The government has recognised data centres as essential for maintaining the UK’s competitive edge in AI and cloud computing, and this decision reinforces that grey belt land can accommodate strategic development beyond residential schemes, especially when they align with national strategic objectives and offer substantial local benefits. The grey belt designation is already increasing the number of data centres in the Green Belt, allowing for strategic infrastructure projects that align with national tech investment priorities while ensuring environmental enhancements.

6. Burcot, South Oxfordshire - approved development

  • Location: Burcot, South Oxfordshire
  • Type of development: 57-hectare solar farm
  • Key planning considerations:
    • Initially refused due to concerns over its impact on the Oxford Green Belt, the scheme was later reclassified as grey belt under the updated NPPF 2024.
    • The Planning Inspectorate granted consent following an inquiry in February 2025, confirming that large-scale renewable energy projects can be suitable for grey belt land.
    • The council withdrew its Green Belt objection after acknowledging that the site met paragraph 155 of the NPPF, making the development no longer "inappropriate."
    • A statement of common ground between key parties confirmed the grey belt designation, which the inspector accepted, paving the way for approval.
    • The site comprises 100% Best and Most Versatile (BMV) agricultural land, but the inspector concluded that solar panels would not prevent continued farming use and that the land could revert to agriculture once the development's lifespan ended.
  • Outcome: Planning permission granted
  • Key lesson: This decision sets a precedent for renewable energy projects on grey belt land, reinforcing that once a site qualifies under paragraph 155 of the NPPF, standard Green Belt constraints no longer apply.

7. Elmbridge, Surrey - rejected development

  • Location: Elmbridge, Surrey
  • Type of development: Mixed-use scheme (housing, commercial, and waste recycling)
  • Key planning considerations:
    • The site was previously developed land, meeting the grey belt definition under the updated NPPF 2024.
    • Despite partial enclosure by existing infrastructure, the Inspector determined this was insufficient to justify development, as the site still played a role in preventing urban sprawl.
    • Residents expressed concerns over increased traffic and environmental impacts, influencing the decision.
  • Outcome: Appeal dismissed
  • Key lesson: Meeting grey belt criteria does not guarantee approval; additional factors like site context, infrastructure adequacy, and community concerns are crucial in planning decisions.

8. Billericay, Basildon - approved development

  • Location: Billericay, Basildon
  • Type of development: 250-home residential scheme
  • Key planning considerations:
    • Council officers identified the site as grey belt under the updated NPPF 2024 criteria, acknowledging its potential for development.
    • Basildon has a history of strong opposition to Green Belt releases, making this approval noteworthy.
    • Officers recommended approval based on pressing housing needs and the site's alignment with local development constraints.
  • Outcome: Planning permission granted
  • Key lesson: Even in areas with strong Green Belt opposition, meeting grey belt criteria and demonstrating housing need can result in approval.

9. Leighton Buzzard, Central Bedfordshire - rejected development

  • Location: Leighton Buzzard, Central Bedfordshire
  • Type of development: Extra-care housing scheme comprising 99 extra-care units (including 30% affordable housing) and a 66-bed care home​
  • Key planning considerations:
    • The site was acknowledged to meet grey belt criteria under the updated NPPF 2024, as it did not strongly contribute to Green Belt purposes.
    • The proposed development included 30% affordable housing, falling short of the Golden Rules requirement of 50% for grey belt sites.
    • While there was an evident need for extra-care housing, the Inspector determined that the scheme did not deliver sufficient public benefits to outweigh the harm to the Green Belt.
    • Lack of strong transport links and concerns over sustainability were also cited.
  • Outcome: Appeal dismissed
  • Key lesson: Grey belt classification alone is insufficient for approval; developments must meet the Golden Rules for affordable housing, provide significant public benefits, and be located in a sustainable location with strong infrastructure and transport connections.

10. Northaw, Welwyn Hatfield – approved development

  • Location: Northaw, Welwyn Hatfield
  • Type of development: Extra care housing scheme with ancillary community facilities
  • Key planning considerations:
    • The 11.4-hectare site, previously used as greyhound kennels, was recognised as previously developed land and reclassified as grey belt under the updated NPPF 2024.
    • The Inspector concluded the scheme would not cause substantial harm to the openness of the Green Belt, due to its containment by woodland and the careful design restricting development to 23% of the site.
    • Although the proposal failed to meet the 50% affordable housing requirement under the Golden Rules, offering only a 10% discount sale and £1m contribution, the Inspector found this shortfall did not outweigh the scheme’s wider benefits.
    • Those benefits included a projected 14.8–28% biodiversity net gain, enhanced woodland management, and a wheelchair-accessible on-demand electric vehicle service for residents.
    • The Inspector also determined that the proposal would not harm the setting of the nearby Grade II listed Hook House, nor adversely affect the surrounding landscape character.
  • Outcome: Planning permission granted
  • Key lesson: Grey belt sites that qualify as previously developed land and deliver strategic community or specialist housing, with strong landscape containment and environmental gains, may be approved even where affordable housing provision falls short of the Golden Rules.

11. Brierley, Barnsley – approved development

  • Location: Brierley, Barnsley
  • Type of development: Gypsy/Traveller caravan site with day room and associated residential use
  • Key planning considerations:
    • The site was identified as grey belt under the updated NPPF 2024, as it did not strongly contribute to the Green Belt purposes.
    • Although not previously developed land, it was enclosed by allotments and housing, and formed a small part of the wider Green Belt, meaning its development would not undermine the Green Belt’s overall function.
    • The Inspector found a demonstrable unmet need for Gypsy/Traveller pitches in Barnsley, with no progress on allocated sites and an outdated land supply assessment.
    • The development was located next to the village and gave the family access to local services, making it a sustainable location.
    • The site was well maintained, with limited visual impact and no harm to the character of the area or neighbours’ amenity.
    • Although retrospective, the appeal was allowed with conditions securing landscaping, lighting, and biodiversity improvements.
  • Outcome: Planning permission granted
  • Key lesson: Traveller sites on grey belt land may be approved where there is unmet need, the site is small and sustainable, and the development causes no harm to the openness or character of the Green Belt.

12. Dormansland, Tandridge – approved development

  • Location: Dormansland, Tandridge
  • Type of development: Four semi-detached dwellings
  • Key planning considerations:
    • The site was classified as grey belt under the updated NPPF 2024, as it did not strongly contribute to any of the Green Belt purposes.
    • Surrounded by housing, a village church and other development, the site was found to be well-contained and played no meaningful role in checking urban sprawl, preventing settlement merging, or preserving historic character.
    • The Inspector concluded that development would not fundamentally undermine the wider Green Belt and met the requirements of paragraph 155 of the NPPF.
    • Tandridge’s shortfall in housing land supply—at just 1.92 years—demonstrated a clear unmet need for new homes, adding weight in favour of the scheme.
    • Although located in a rural area, the site offered good access to public transport, including nearby railway stations and local bus services, and was considered to be in a sustainable location.
    • The proposal included EV charging points, cycle storage and a pedestrian link to improve connectivity, and the Inspector concluded it would not harm local character or highway safety.
  • Outcome: Planning permission granted
  • Key lesson: Grey belt sites that are enclosed by existing development and located near transport links are likely to succeed where housing need is high and the proposal meets the criteria of paragraph 155.

13. Navestock, Brentwood – approved development

  • Location: Navestock, Brentwood
  • Type of development: Six-pitch Gypsy/Traveller site with day rooms and hardstanding
  • Key planning considerations:
    • The site was designated grey belt under the updated NPPF 2024, as it made only a limited contribution to Green Belt purposes.
    • The Inspector emphasised that grey belt assessments should be made at a site-specific level, rather than relying solely on parcel-based strategic reviews.
    • As a small, contained site between two existing traveller sites, the proposal was not considered inappropriate under paragraph 155.
    • There was a clear unmet need for Gypsy/Traveller pitches in Brentwood and no alternative sites available.
    • The Inspector also noted the proposal would not harm openness or local character, and that the Golden Rules do not apply to this type of development.
  • Outcome: Planning permission granted
  • Key lesson: Traveller sites may be approved on grey belt land where they meet paragraph 155, especially if they are small, contained, and respond to a clear local need.

14. Copthorne, Tandridge – approved development

  • Location: Copthorne, Tandridge
  • Type of development: Two detached dwellings with a garage
  • Key planning considerations:
    • The appeal site was confirmed as grey belt under the updated NPPF 2024, as it did not strongly contribute to Green Belt purposes (a), (b), or (d).
    • The Inspector concluded that, while the proposal would result in a small loss of openness, it would not fundamentally undermine the purposes of the remaining Green Belt.
    • Tandridge’s housing land supply stood at just 1.92 years, demonstrating a clear unmet need.
    • The site was considered to be in a sustainable location, with good access to nearby settlements despite limited footpath links.
    • As a minor development, the scheme was not subject to the Golden Rules, and the Inspector gave reduced weight to pre-framework local policies that didn’t account for grey belt.
  • Outcome: Planning permission granted
  • Key lesson: Small-scale residential developments on grey belt land may be approved where they meet paragraph 155 of the NPPF, particularly when housing need is high and the Golden Rules do not apply.

15. Wickford, Basildon – approved development

  • Location: Wickford, Basildon
  • Type of development: Single bungalow (retrospective application)
  • Key planning considerations:
    • The site was recognised as grey belt under the 2024 Written Ministerial Statement and draft NPPF, due to its limited contribution to Green Belt purposes and lack of aesthetic or environmental value.
    • Although the application was retrospective and not previously developed land, the Inspector considered the site to be part of a settlement-edge plotlands area, enclosed by other development and in a sustainable location near Wickford.
    • Basildon’s 2.34-year housing land supply was well below the required five years, and the Inspector gave significant weight to the national policy direction encouraging the early release of grey belt land.
    • The scheme was not found to cause significant harm to openness, and mitigation payments had already been made to offset potential impact on the Blackwater Estuary SPA and Ramsar site.
  • Outcome: Planning permission granted
  • Key lesson: This case illustrates how grey belt status may support approval even ahead of formal policy adoption, particularly for small-scale housing in sustainable locations within authorities facing acute housing shortages.
Directors at Urbanist Architecture in a professional meeting discussing building plans. The chartered town planner, with curly hair and dressed in a black blouse, and the chartered architect, with short grey hair and wearing a black shirt, are seated at a polished wooden table with architectural blueprints spread out in front of them. They are deeply engaged in reviewing the designs, symbolising collaboration and expertise in architectural planning.

Are grey belt decisions becoming more predictable or more confusing for landowners?

While the introduction of grey belt policy has led to significant planning approvals, decisions by planning inspectors have been inconsistent, reflecting differing interpretations of the new policy across the country.

For instance, in St Albans and Hertsmere, grey belt designations were accepted, leading to approvals for major housing and infrastructure projects. These decisions aligned with the government's intention to prioritise previously developed or low-performing Green Belt land for development.

In contrast, in Beaconsfield, an inspector took a far stricter approach, rejecting a 120-home development despite the site being enclosed by major roads. The decision rested on the site’s continued role in preventing urban sprawl, despite its physical separation from open countryside. This case highlights that while grey belt aims to streamline development approvals, some inspectors still adhere to traditional Green Belt protections, particularly where past assessments categorised land as serving a containment function.

Similarly, in Surrey, a mixed-use development including housing and commercial space was refused despite being located on a waste processing site. The inspector acknowledged that the land met the grey belt definition but argued that its partial enclosure by existing infrastructure was insufficient to justify development.

The bottom line?

The grey belt policy is still evolving, and planning inspectors’ decisions remain inconsistent. Local plans and emerging case law will play a crucial role in defining how grey belt land is assessed and approved moving forward. For developers and landowners, monitoring planning appeal outcomes is essential to understand how different factors - such as a site's history, physical constraints, and role in preventing urban sprawl - affect decisions.

A section of cleared land within the Green Belt, illustrating the concept of grey belt. The image shows underutilised, low-quality land with minimal vegetation, representing areas targeted for housing development under Labour's grey belt plans. This initiative aims to address the UK's housing shortage by utilising land with limited environmental value.

How big is the grey belt?

Think the grey belt is insignificant? The numbers tell a different story and they demand our professional attention.

Digging into the research uncovers a stark contrast in findings. Various assessments highlight significant disparities in the measurement of grey belt land.

The Times suggests roughly 3% of England's Green Belt (approximately 46,871 hectares) could be classified as grey belt, while Knight Frank has identified over 11,000 previously developed sites with potential to deliver between 100,000 and 200,000 dwellings.

More ambitious figures emerge from LandTech, which proposes that up to 300,000 homes could be constructed on such land. Searchland offers the most expansive estimate: 30,597 grey belt sites potentially accommodating 3.4 million homes.

What does this tell us?

This variation illuminates both the ambiguous nature of grey belt classification and divergent assumptions regarding development capacity. Whilst some adopt a cautious stance, concentrating on specific parcels and reasonable housing densities, broader assessments highlight the considerable volume of land that could be repurposed.

Here’s the common thread: Across all analyses, grey belt land represents a significant, yet underexploited opportunity. But there’s a catch. Unlocking these sites depends on how planning officers and inspectors interpret the revised NPPF and Green Belt PPG.

Even accepting only the most conservative estimate, the grey belt presents substantial potential for helping to address the UK’s housing crisis, offering a pragmatic solution that balances development needs with environmental protection.

A collection of National Planning Policy Framework (NPPF) documents dated December 2024, published by the Ministry of Housing, Communities & Local Government. The documents reflect recent planning reforms, including relaxed Green Belt policies and the introduction of 'grey belt' land to prioritise housing development on underutilised sites while maintaining environmental considerations.

Why has grey belt become part of planning reform?

Strategically, grey belt was introduced to unlock sites for housing while maintaining essential Green Belt protections. By designating underutilised or previously developed land that makes a limited contribution to Green Belt purposes, the policy directs growth to areas where it is most sustainable.

This approach enables local authorities to meet housing targets while minimising the need for widespread Green Belt release. It also helps tackle the UK's housing crisis by optimising land use, easing pressure on greenfield sites, and simplifying the planning process for appropriate developments.

But there’s a challenge: To realise this potential, we believe that political courage is the cornerstone of successful grey belt development. Without resolute leadership and precise policy guidance, local authorities will inevitably falter, constrained by fears of public opposition and legal challenges.

Firm government backing is essential to empower planning officers, streamline development processes, and deliver the sustainable housing growth that our communities so urgently require.

A close-up image of a barbed wire fence post in a field of tall grass, representing the Green Belt in England.

What other changes are being made to Green Belt planning rules?

As part of their Green Belt reform, the government has pledged to prioritise developing grey belt and brownfield land, grant new devolved planning powers to regions, and reform compulsory purchase rules for faster land assembly.

But that's not all. The new government will also identify locations to create a series of new towns to help alleviate housing shortages. This involves building entirely new communities with integrated infrastructure, public services, and green spaces. The objective of these new large-scale towns is to provide high-quality, affordable housing and foster sustainable residential-led developments.

The relaxations in the planning process for building within the Green Belt will be guided by the previously mentioned Golden Rules which include:

  • Affordable homes: Major development must target at least 50% affordable housing delivery when land is released.
  • Boost public services and infrastructure: Plans must boost public services and local infrastructure, like more school and nursery places, new health centres and GP appointments. 
  • Improve genuine green spaces: The government requires plans to include improvements to existing green spaces, making them accessible to the public, with new woodland, parks and playing fields. Plans should meet high environmental standards.

Additionally, when it comes to allocating Green Belt land for development, LPAs have been instructed to first consider brownfield land, then grey belt areas that are not previously developed, before reviewing other Green Belt locations for housing development as their final option.

Industrial wasteland within the Green Belt, exemplifying grey belt land with poor environmental quality and underutilised spaces. The image shows debris, old machinery, and neglected areas, highlighting the potential for redevelopment into housing under Labour's grey belt plans to help address the UK's housing crisis.

Is the Green Belt really as green as people think?

It’s crucial to pinpoint a couple of Green Belt myths that, in my opinion at least, are mostly to blame for these changes not going ahead sooner.

If you’re worried that these changes mean environmental destruction, then I need you to read the two key points below.

Let’s take a look.

A large amount of Green Belt is not green

One common misconception about the Green Belt is that all of it is lush, verdant, and pristine.

While much of the Green Belt is indeed green, a significant portion does not fit this idyllic image. In fact, around 65% of Green Belt land is agricultural, but much of the remainder consists of former industrial sites, low-grade farmland, or land with limited ecological value.

In London, for example, 76% of the Green Belt is classified as low environmental quality, often featuring defunct agricultural buildings and areas with minimal biodiversity. Additionally, a substantial portion of the Green Belt is privately owned and inaccessible to the public, challenging the notion that it serves as a shared public resource.

Green Belt policy is not for environmental protection

Though many people believe that the Green Belt exists to protect wildlife, special landscapes, and historic assets, the reality is that the Green Belt policy isn’t primarily concerned with environmental preservation; its primary purpose is to contain the expansion of cities and prevent urban sprawl. 

With this in mind, the term 'green' can be misleading, as the designation and protection of Green Belt land is based on its location rather than its environmental or scientific value.

Construction site with partially built houses, illustrating the development of new residential areas within the Green Belt. The image highlights the construction process and the potential for grey belt land to be used for housing, aligning with Labour's plans to address the UK's housing crisis.

Does CPRE support or oppose grey belt development?

The Campaign to Protect Rural England (CPRE), a lobbying group with strong beliefs against building in the Green Belt, has expressed nuanced and sometimes mixed reactions to the concept of grey belt development. In short, CPRE's view on grey belt could be described and summarised as cautiously supportive. 

CPRE acknowledges that some low-quality grey belt land may be suitable for development and argues that brownfield sites should be prioritised. However, estimates indicate that brownfield land alone could only meet housing demand for around four years, highlighting the need for alternative solutions.

That’s not their only concern. CPRE also argues that some degraded sites could be restored as valuable habitats rather than being developed, advocating for a case-by-case approach to ensure environmental protections are upheld.

And then there’s another issue. CPRE warns against speculative degradation, where landowners might intentionally degrade land to gain grey belt reclassification. To combat this, they call for strict environmental safeguards and robust planning controls.

As a solution, we believe that an independent commission can be established to provide the necessary oversight and uniformity to address these concerns effectively. This body could ensure that grey belt classifications are made transparently and equitably, preventing unethical practices and ensuring that environmental integrity is maintained.

Town planners at Urbanist Architecture discussing planning strategies for sustainable development within the Green Belt. The consultant uses a tablet to present information, showcasing Urbanist Architecture's personalised approach and expertise in navigating grey belt policies to create eco-friendly housing solutions. This highlights the firm's dedication to helping clients achieve successful planning outcomes.

Our views on the grey belt

An often-overlooked point is that allocating grey belt land for development requires navigating the complex dynamics between local priorities and national standards. Because local authorities often focus on immediate economic benefits, this approach can overshadow the need for long-term environmental sustainability. 

Conversely, national guidelines and design codes that standardise practices across regions might not deliver the type of relevant housing solutions effectively, leading to a one-size-fits-all approach that lacks local context, the unique characteristics and needs of individual local authorities. For example, while some councils may need high-density urban extensions, others might require lower-density suburban growth, making rigid national policies challenging to implement effectively.

The analyses conducted by Knight Frank, which identified over 11,000 grey belt sites across England, also highlights that these sites are not evenly distributed. Remarkably, 41% of these sites are concentrated within London’s Green Belt, with significant numbers also found in Greater Manchester, Birmingham, and South and West Yorkshire. 

In practical terms, this uneven distribution implies that some regions may gain more from grey belt development than others, potentially intensifying regional disparities in housing availability and economic growth. Addressing these disparities requires careful planning and targeted support for regions with fewer grey belt opportunities.

The simple truth is that if we are to meet the growing demand for housing in the UK, it is essential that we release some Green Belt land for development. The release of even a small percentage of the Green Belt, including low-quality grey belt land, could significantly help accommodate several years' worth of housing needs but only if planned and designed holistically. This must be complemented by investment in transport, utilities, and local services to prevent placing excessive strain on existing infrastructure.

The government has also recently announced it is reinstating mandatory local housing targets, which were relaxed by the previous government. To that end, by local councils releasing publicly owned grey belt land to national housebuilders and SME developers, the delivery of new sustainable communities can be significantly accelerated.

To move forward, greater clarity is needed on how grey belt sites will be prioritised within local plans and whether additional funding will be allocated to support their infrastructure needs.

Architects and town planners from Urbanist Architecture collaborating on a Green Belt masterplanning project. The team is engaged in a design discussion, surrounded by architectural drawings, with a site plan for a Green Belt development displayed in the background.

How Urbanist Architecture can help you

While grey belt designation offers a pathway forward, winning approvals demands both meticulous site analysis and strategically crafted justification for the application.

Our team of Green Belt architects and planning consultants is fast earning a reputation as one of the country’s leading planning and architecture firms - particularly when it comes to Green Belt planning permission - and we know how to produce results that meet the expectations of the council while exceeding those of our clients.

In fact, we’ve written a whole book on it, which is available for purchase now if you’re interested.

Nicole Ipek Guler, Charted Town Planner and Director of Urbanist Architecture
AUTHOR

Nicole I. Guler

Nicole leads our planning team and specialises in tricky projects, whether those involve listed buildings, constrained urban sites or Green Belt plots. She has a very strong track of winning approval through planning appeals.

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