Green Belt and Grey Belt Explained: What Can Be Built, Extensions, and What It Means Nearby (NPPF 2026)

01

What the green belt is, and who decides where it is

The Government's stated objective is "to prevent urban sprawl by keeping land permanently open", and the "essential features" of Green Belts are "their openness and permanence" (NPPF chapter 13). Policy GB2 gives the five purposes:

• (a) to check the unrestricted sprawl of large built-up areas;
• (b) to prevent neighbouring towns merging into one another;
• (c) to assist in safeguarding the countryside from encroachment;
• (d) to preserve the setting and special character of historic towns; and
• (e) to assist urban regeneration by encouraging the recycling of derelict and other urban land.

Councils map it, and only local plans can change it. Boundaries "should only be altered through the preparation and updating of local plans and where exceptional circumstances are fully evidenced and justified" (GB3(1)), except around well-connected stations where a spatial strategy has identified land and "exceptional circumstances do not need to be demonstrated" (GB3(4)). For how local plans work, see local plans explained.

It operates through development plan policy. Its boundaries are shown on the local plan's policies map, and decisions follow the development plan unless material considerations indicate otherwise (Planning and Compulsory Purchase Act 2004 s38(6), applied in the PPG at 64-010), and the NPPF's policies are material considerations "from the day of its publication" (Annex A, para 1).

How to check whether land is in the green belt. Look at your council's local plan policies map. The national green belt dataset on planning.data.gov.uk holds boundaries from councils' annual returns, but each March's returns are published the following autumn, so it "won't reflect any changes to green belt boundaries made since the local planning authorities submitted their annual returns".

What it is not. The Green Belt is not the same as farmland, "greenfield" land, a conservation area or a National Landscape. Farmland can be inside or outside it. Land outside the Green Belt and outside settlements is dealt with by a different policy, S5, which has its own list of acceptable development. Green Belt land itself can be built on, as the next section explains.

02

Inappropriate development, and the exceptions (GB6 and GB7)

Policy GB6 is the rule: "development in the Green Belt is inappropriate unless it falls within one of the categories in policy GB7". Inappropriate development "is, by definition, harmful to the Green Belt and should not be approved except in very special circumstances". Those exist only if the harm by reason of inappropriateness "and any other harm… is clearly outweighed by other considerations", and "substantial weight should be given to the harm to the Green Belt which would be caused, including harm to its openness" (GB6(2)).

Policy GB7(1) lists the development that is not inappropriate, and which therefore does not need very special circumstances:

Extending a house in the green belt

Two different routes apply, and it helps to keep them apart.

1. Within permitted development, no application is needed. See below.
2. If you need planning permission, GB7(1)(b) is the test: the extension must not result in a "disproportionate increase in size compared to the original building". Footnote 40 defines the original building as "the building that existed on 1 July 1948 or, if constructed after 1 July 1948, as it was built originally". The NPPF sets no percentage. Any figure you are quoted comes from your council's local policy, so ask for it. Also note the building must be "lawful in planning terms": a building put up without permission, and still open to enforcement, is not within GB7(1)(b). One that has become immune from enforcement is lawful (TCPA s191(2)), and a lawful development certificate proves it (see retrospective planning permission).

For outbuildings, log cabins and caravans in the green belt and other protected places, see log cabins in conservation areas, AONBs and National Parks and log cabins on agricultural land or paddocks.

03

What "grey belt" means

The idea was introduced by the December 2024 NPPF. The current definition, in the Annex B glossary, is:

"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 policy GB2."

Three consequences follow from that wording.

• Only three purposes count. Land can be grey belt even if it contributes strongly to purpose (c), safeguarding the countryside from encroachment, or (e), urban regeneration.
• It is wider than "brownfield". Previously developed land is "land which has been lawfully developed and is or was occupied by a permanent structure and any fixed surface infrastructure associated with it", but excludes, among other things, land last occupied by agricultural or forestry buildings, land with a restoration requirement (such as former mineral workings, landfill or temporary renewable energy sites), land where the old structures "have blended into the landscape", and "land in built-up areas such as residential gardens, parks, recreation grounds and allotments". Grey belt takes in that land and other land that does not strongly contribute to purposes (a), (b) or (d), including open ground. A site can be grey belt without ever having had a building on it.
• Grey belt is not a free pass. Being grey belt only opens the GB7(1)(g) route, and the PPG says "where grey belt is identified, it does not automatically follow that it should be allocated for development, released from the Green Belt or for development proposals to be approved in all circumstances" (PPG, Green Belt, introduction to the grey belt assessment section).

How the three purposes are judged. Annex E sets "illustrative features" of strong, moderate and weak or no contribution. For purpose (a), a strong contribution is likely where land is free of existing development, lacks physical features that could contain development, is adjacent or near to a large built-up area, and would result in an "incongruous pattern of development". For purpose (b), a strong contribution means it forms a substantial part of a gap between towns and its development would be likely to lose their visual separation. For purpose (d), it forms part of a historic town's setting and makes a "considerable contribution" to its special character. Villages are not "large built-up areas" for (a) (Annex E para 3); purpose (b) concerns towns, which "includes cities" (para 4 and footnote 77), and purpose (d) concerns historic towns, in each case "not villages" (paras 4–5).

A caution about the PPG. The Planning Practice Guidance on the Green Belt was last updated on 27 February 2025, to reflect the 2024 NPPF. It still refers to "paragraph 155 of the NPPF" for the grey belt conditions (PPG 64-001, 64-010) and, at 64-006, describes the definition as excluding land where "policies relating to the areas or assets in footnote 7" would "provide a strong reason for refusing or restricting development". The Annex B definition quoted above, as published on 17 August 2026, contains no such clause. Its other paragraph references are December 2024 numbers too (147 and 148 at 64-001, 110 and 115 at 64-011, and footnote 55 at 64-014). Treat the PPG as a guide to method, and the August 2026 NPPF text as the rule. Cite policies by code, for example GB7(1)(g), not by paragraph number. (The NPPF's HTML chapter pages show "Published 29 September 2026", the date the accessible version was added; the Framework itself was published on 17 August 2026.)

04

The four tests for grey belt development (GB7(1)(g))

Development on grey belt land is "not inappropriate" only where all of the following apply:

1. "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";
2. "There is an evidenced unmet need for the type of development proposed". Footnote 41 defines this for housing as "the lack of a five year supply of deliverable housing sites, including the relevant buffer where applicable, or where the Housing Delivery Test result was below 75% of the housing requirement over the previous three years";
3. "The development would be in a sustainable location", with particular reference to policy TR3 (locating development in sustainable locations); and
4. For major development involving housing, it complies with the Golden Rules in GB8.

For housing, "major" means 10 or more homes, or a site of 0.5 hectares or more (Annex B).

The Golden Rules (GB8)

Where major housing development is proposed on land released from the Green Belt through a plan, or on a Green Belt site subject to a planning application, GB8(1) asks for all of:

• Affordable housing: either the development plan's policy level for such land, or until one is in place "a contribution which is 15 percentage points above the highest existing affordable housing requirement which would otherwise apply… subject to a cap of a 50%", with 50% applying by default where no requirement exists;
• Necessary improvements to local or national infrastructure; and
• Accessible green space, whether new or improved, that makes a positive contribution to the landscape setting, supports nature recovery and meets local or national standards.

"Substantial weight should be given to the importance of complying with the Golden Rules" (GB8(2)). A viability assessment can be used in only three circumstances: previously developed land with unforeseen costs, a strategic site, or development of a wholly different type to that tested in the plan's viability work (GB8(3)), and even then "the maximum possible contribution" is still expected (GB8(4)). The Rules do not apply to land released through plans adopted, or permissions granted, before 12 December 2024, nor to traveller sites (footnote 43); the 50% cap does not apply to rural exception sites or community-led exception sites, or where an existing local policy already requires more than 50% (footnote 44).

"Not inappropriate" is not "approved"

Passing GB7 removes the need for very special circumstances (PPG 64-014), but it does not grant permission or take the land out of the Green Belt: "Where a development is not inappropriate in the Green Belt, this does not itself remove the land from the Green Belt nor require development proposals to be approved" (PPG 64-010). Under the August 2026 NPPF, though, it does shift the balance. Policy S5(5) says that where development "would not be inappropriate" in the Green Belt (through GB7), "proposals should be approved unless the benefits of doing so would be substantially outweighed by any adverse effects, when assessed against the national decision-making policies in this Framework". Those adverse effects include failing to comply with a national policy that says development should be refused in specific circumstances (S5(2)). A grey belt scheme can still be refused, for example on flood risk, heritage, highways or design grounds, but an objector has to show that the harm substantially outweighs the benefits. The 2025 PPG predates this policy and does not reflect it.

05

Very special circumstances

Development that is inappropriate can be approved only if very special circumstances exist. GB6(2) sets the test: the harm by reason of inappropriateness and any other harm must be "clearly outweighed by other considerations", with substantial weight given to Green Belt harm including harm to openness. GB6(3) adds that for renewable and low carbon energy development, "very special circumstances may include the wider environmental benefits associated with increased production of energy from renewable sources". The PPG says assessing openness is a matter of judgement based on the case, taking account of "spatial and visual aspects", the "duration of the development, and its remediability", and "the degree of activity likely to be generated, such as traffic generation" (PPG 64-013).

06

Permitted development still applies in the green belt

This is one of the most common misunderstandings. Permitted development is granted nationally by the GPDO 2015, and the General Permitted Development Order restricts specific rights on "article 2(3) land", which Schedule 1 Part 1 lists as land within:

• a conservation area;
• an area of outstanding natural beauty (a National Landscape);
• an area specified under section 41(3) of the Wildlife and Countryside Act 1981;
• the Broads;
• a National Park; and
• a World Heritage Site.

The Green Belt is not on the list. The householder parts of the Order (Part 1, Part 2) and Part 14 on renewables contain no Green Belt exclusion. So a house in the green belt keeps its Class A rear extension right, covered in Do I need planning permission for an extension? (up to 3 m, or 4 m if detached, or 6 m / 8 m under the larger home extension prior approval route, which is limited only on article 2(3) land and sites of special scientific interest: Class A, A.1(f)–(g)), its loft rights, its outbuilding right under Class E and the rest, subject to the usual conditions. Where permission is not needed, the "disproportionate" test in GB7(1)(b) is not applied, because there is no application to which to apply it. Rights can still be removed on a particular house by a planning condition (GPDO art 3(4)) or an Article 4 direction. The same "original" date applies: 1 July 1948 or as built if later.

National Landscapes and National Parks are different. They are article 2(3) land, so, for example, the 6 m / 8 m route is unavailable, no Class B roof enlargement (dormer, hip-to-gable or otherwise) is permitted (B.1(f)), and Class E caps buildings more than 20 m from the house at 10 m² in total (E.2). For conservation areas see Conservation Areas and Planning.

07

National Landscapes (the AONB rename)

"National Landscape" is the current name for an area of outstanding natural beauty. The NPPF glossary defines National Landscapes as "areas legally designated as areas of outstanding natural beauty under the National Parks and Access to the Countryside Act 1949 and Countryside and Rights of Way Act 2000", and Natural England designates them under s82 of the 2000 Act. The GPDO itself still says "area of outstanding natural beauty". Three things matter in practice.

• A stronger duty. Levelling-up and Regeneration Act 2023 s245 inserted a new subsection (A1) into s85 of the 2000 Act: in exercising functions affecting land in an AONB in England, a relevant authority "must seek to further the purpose of conserving and enhancing the natural beauty of the area". That has applied since 26 December 2023. It replaced the former duty merely to have regard to that purpose (which remains the duty in Wales).
• A strong planning policy. NPPF policy N4 says development within Protected Landscapes (National Parks, the Broads and National Landscapes) "should be limited in scale and extent", with "substantial weight" on conserving and enhancing natural beauty, and that proposals for major development "should be refused other than in exceptional circumstances, and where it can be demonstrated that the development is in the public interest", after assessing need, the cost of developing elsewhere and any detrimental effect. Whether a proposal is "major" for this purpose is "a matter for the decision-maker" (footnote 59), not the housing definition used above.
• Grey belt does not override it. GB7 deals with the Green Belt only; the PPG confirms wider policies in the NPPF read as a whole still apply (PPG 64-010). A site in both the Green Belt and a National Landscape has to pass GB7 and N4.

08

If grey belt development is proposed near you

There are two stages, and different things work at each.

1. The local plan stage. Green Belt boundaries move only through a local plan (GB3(1)). Plans must be informed by a Green Belt assessment under Annex E that "identifies grey belt" (GB2(3)). When boundaries are altered, the policy sets a priority: "previously developed land within the Green Belt, then to grey belt land which is not previously developed, and then other Green Belt locations, so long as this promotes a sustainable pattern of development overall" (GB4(1)(d)(i)), and allocations for major housing on released land must be capable of meeting the Golden Rules (GB4(1)(e)). So the call for sites, the Green Belt assessment and the draft plan consultation are where release is really decided. Annex A tells you which version of the NPPF a plan follows: plans being prepared under the new regime follow the August 2026 text (Annex A paras 4 and 7); other plans follow the December 2024 version (para 8).

2. The application stage. A "grey belt" proposal arrives as a planning application. Publicity rules (DMPO art 15) depend on the type:

• major development: a notice in a local newspaper, plus a site notice displayed for not less than 21 days or letters to adjoining owners and occupiers (art 15(4));
• development that does not accord with the development plan: press advertisement and a site notice for not less than 21 days (art 15(2)–(3));
• an EIA application with an environmental statement: a site notice for at least 30 days and a newspaper notice, with at least 30 days to comment (art 15(1A), (7)(c));
• in every other case, details are published on the council's website and representations must be allowed for at least 14 days from publication (art 15(7)(c)).

For applications made on or after 1 April 2026, most appeals decided in writing use the expedited procedure (SI 2026/122). In that procedure your original comments are forwarded to the Inspector and you cannot add to them (DMPO art 15(7)(f)). If the appeal goes to a hearing or inquiry, which is common for large housing schemes, neighbours can usually comment again (PPG Appeals 16-010). Either way, put your whole case in at the application stage.

What counts. Planning grounds only. For a GB7(1)(g) scheme the checkable points are: whether the land really does not "strongly contribute" to purposes (a), (b) and (d) (the council's Green Belt assessment is the first evidence); whether the "unmet need" claim is evidenced against footnote 41; whether the location is sustainable under TR3; whether the proposal would "fundamentally undermine" the remaining Green Belt; and, for major housing, whether the Golden Rules are met, with viability claims tested against GB8(3). If the land is in a National Landscape, N4 as well. Remember the S5(5) test: for a scheme that is not inappropriate, the question is whether its adverse effects substantially outweigh its benefits. See how to object to a planning application, what are material planning considerations, can I stop a planning application and new housing development near me.

To hear about applications as they are submitted, set up a PlanWatch alert for your postcode.

09

Common myths

• "You can't build anything in the green belt." False: GB7 lists what is not inappropriate, and very special circumstances can justify the rest.
• "Permitted development doesn't apply in the green belt." It does. The green belt is not article 2(3) land.
• "The rule is NPPF paragraph 155." That was the December 2024 number. The August 2026 NPPF uses policy codes: GB7(1)(g) for grey belt.
• "Grey belt means brownfield." It includes brownfield land but also other land that does not strongly contribute to purposes (a), (b) or (d).
• "Green belt, AONB and conservation area are the same." They are three separate regimes. The green belt is a planning-policy designation made through local plans; a National Landscape is a statutory designation by Natural England; a conservation area is designated by the council under s69 of the 1990 Act.
• "Green belt boundaries are fixed for ever." They are "permanent" in intention, but can be altered through a local plan where exceptional circumstances are fully evidenced (GB3).

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Wales, Scotland and Northern Ireland

Everything above, including grey belt and the Golden Rules, is English NPPF policy. The other nations differ.

• Wales. Planning Policy Wales, Edition 12 (Edition 12, February 2024; the page was last updated 19 July 2024: landing page) provides for Green Belts and local "green wedges". There is "a general presumption against development which is inappropriate in relation to the purposes of the designation" (3.69), "a presumption against inappropriate development will apply" with "substantial weight" to harm (3.73), and new buildings are inappropriate unless they are for "justified rural enterprise needs", outdoor sport and recreation facilities and similar uses that maintain openness, "limited extension, alteration or replacement of existing dwellings", or small-scale farm diversification (3.75). Areas of outstanding natural beauty in Wales are designated by the Natural Resources Body for Wales under s82(2) of the 2000 Act, and the duty on public bodies there is still to "have regard" (s85(1)).
• Scotland. National Planning Framework 4, Policy 8 (Green belts) says proposals within a green belt designated in a local development plan "will only be supported" if they are one of a list of types (including agriculture and forestry, outdoor recreation, essential infrastructure, "extensions to an existing building where that is ancillary to the main use" and "one-for-one replacements of existing permanent homes") and meet requirements such as showing why a green belt location is essential, and not undermining the green belt's purpose.
• Northern Ireland. The Strategic Planning Policy Statement, Edition 2 (December 2025) contains no green belt policy in its text. Development outside settlements is governed by its countryside policy (the section headed "Development in the Countryside", from para 6.61), and para 1.11 retains the policy provisions of PPS 21, Sustainable Development in the Countryside, which still sets most of the tests for building outside settlements. Check the area's development plan, which may show Green Belt designations.

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Related guides

• Local plans explained
• New housing development near me
• How to object to a planning application
• Conservation areas and planning
• Article 4 directions explained
• Permitted development rights explained
• Log cabins in conservation areas, AONBs and National Parks

This guide is general information, not legal advice. Policy checked against GOV.UK and law against legislation.gov.uk as at 20 October 2026. PPG paragraph numbers are the Reference IDs printed after each paragraph on GOV.UK. Whether a particular site is green belt, grey belt or in a National Landscape is a matter for the council's evidence and decision.

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