Green Belt FAQs
Green Belt is a planning designation first established in the 1940s, though debated vigorously from the end of the 1920s. The 1944 London Plan defines a ‘Green Belt Ring’ around all London, although this designation fell short of reaching Hertford, Ware, Sawbridgeworth and Bishop’s Stortford.
As a planning designation, it has remained as a constant but is in a perpetual state of review across the country as planning and development needs change. Whilst the first Green Belt was defined around London, most major cities in England now have a Green Belt around them.
Green Belt serves five purposes (and five purposes alone). They are:
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 in urban regeneration, by encouraging the recycling of derelict and other urban land.
Green Belt land is distinct from ‘greenfield’ land. ‘Greenfield’ typically refers to land which has not been developed. Green Belt land is not always greenfield, and there may be existing development within the Green Belt from car parks to farm buildings and, more occasionally, larger buildings.
Patrick Abercromie, author of the 1944 London Plan, states that the aim of the 1938 Green Belt Act was, ‘chiefly recreational’, but also, ‘provided for the securing and continuing, in their present state, of lands used for farming, recognising the value of thus keeping open large tracts of land for the visual solace of man, as well as safeguarding farmland from building’.
This has evolved over the intervening years and today the fundamental aim of Green Belt policy is to prevent urban sprawl by keeping land permanently open; the essential characteristics of Green Belts are their openness and their permanence.
Green Belt serves five purposes (and five purposes alone). They are:
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 in urban regeneration, by encouraging the recycling of derelict and other urban land.
The Government has monitored the area of the Green Belt since 1997, although consistent figures are only available from 2007. The latest figures from March 2025 suggest that there are 1.63m hectares of land designated as Green Belt, and that this has increased from 1.61m hectares in 2021. The Greater London Green Belt has also increased over this period, from 507,930 to 508,080 hectares.
The Green Belt coverage of England is around 12.5% of the total land area. This compares with 9% of land which is of developed use. When including land designated as Green Belt, just over 37% of the area of England (4.9m hectares) is protected against development by one or more protected area.
Local authority green belt: England 2024-25 - statistical release - GOV.UK
Green Belt in East Hertfordshire is part of the Green Belt that exists around London. Over the years, the Green Belt has changed, and so the Green Belt now surrounds Hertford, Ware, Sawbridgeworth and Bishop’s Stortford, coming up and across from the boroughs of Stevenage, Welwyn Hatfield, Broxbourne, Epping Forest, Harlow and Uttlesford.
The Green Belt does not extend up to Buntingford or cover the central rural parts of the district, and a large area was removed from the Green Belt during the previous East Herts District Plan to allow for the allocation of the Gilston area.
In the adopted East Herts District Plan, agricultural land outside of the Green Belt is designated as ‘Rural Land Beyond the Green Belt’.
Green Belt in East Herts can also be seen on the interactive policies map.
The aim and purposes of Green Belt are defined in the National Planning Policy Framework document. The fundamental aim of Green Belt policy is to prevent urban sprawl by keeping land permanently open; the essential characteristics of Green Belts are their openness and their permanence.
Green Belt serves five purposes (and five purposes alone). They are:
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 in urban regeneration, by encouraging the recycling of derelict and other urban land.
No, Green Belt has just the five purposes listed above. Other designations and allocations serve those other functions, so the Green Belt can have other designations within it and overlapping it.
The National Planning Policy Framework sets out the Government’s planning policies for England and how these should be applied. It was first introduced in 2012 and has been updated and amended several times dependent on the Government’s objectives towards planning and development. The last update was in late 2024, and another update is expected in Summer 2026. The NPPF is supported by more detailed advice called national Planning Policy Guidance.
Once established, Green Belt boundaries should only be altered (including adding land into the Green Belt) where exceptional circumstances are fully evidenced and justified through the preparation or updating of Local Plans. This should be done as part of a long term (strategic) view of the development needs of an area, including its need for additional housing.
Exceptional circumstances exist when a planning authority cannot meet its identified need for development without using areas where there is Green Belt defined. In these circumstances, and only where an authority has exhausted all other reasonable options, authorities should review Green Belt boundaries in accordance with the NPPF and propose alterations to meet these needs in full, unless the review provides clear evidence that doing so would fundamentally undermine the five purposes (taken together) of the remaining Green Belt, when considered across the area of the plan.
Other reasonable options include prioritising suitable previously developed (brownfield) land, optimising the density development and discussing the possibility of neighbouring authorities assisting with meeting housing need.
Grey belt is a category of Green Belt land which was introduced in the December 2024 version of the NPPF. It comprises previously developed land and certain other Green Belt land (including some greenfield land) that does not contribute strongly to Green Belt purposes (a), (b) or (d), which 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.
Grey belt is still Green Belt and the aims and purposes apply to it.
Local authorities will commonly identify potential Grey Belt land through Green Belt Assessments, although applicants may also seek to demonstrate that land meets the Grey Belt definition when submitting planning applications.
Land identified as grey belt is not necessarily suitable for development, and being identified as grey belt provides no indication that the land could come forward for development, or that it should.
In preparing a Local Plan, planning authorities have to consider all other reasonable options and demonstrate exceptional circumstances before considering changes to the Green Belt.
Only then, where it is necessary to release Green Belt land for development, plans should give priority to previously developed land, then consider grey belt which is not previously developed, and then other Green Belt locations. Grey belt is therefore ‘sequentially preferable’ to Green Belt land on the basis that it objectively performs less strongly than areas that are not identified as grey belt.
Planning applications could be submitted on land identified as (or argued as being) grey belt, and use this status as a reason to permit development.
This is also commonly referred to as ‘brownfield land’.
Previously developed land is defined in the NPPF. At its core, it covers land which contains developed land including buildings or infrastructure. It excludes agricultural and forestry buildings and land where restoration has occurred or where development was previously developed but has blended into the landscape. It also excludes open land in built up areas such as parks, allotments and residential gardens.
The NPPF advises that substantial weight is given to any harm to the Green Belt, including harm to its openness. Inappropriate development is, by definition, harmful to the Green Belt and should not be approved except in ‘very special circumstances’.
According to the NPPF, ‘very special circumstances will not exist unless the potential harm to the Green Belt by reason of inappropriateness, and any other harm resulting from the proposal, is clearly outweighed by other considerations’. In other words, the harm to the Green Belt can sometimes be outweighed by the benefit of development. This is a planning judgement. Protection of the Green Belt is not absolute and has to be balanced against other considerations.
Any development in the Green Belt is inappropriate, unless covered by one of the exceptions provided by the NPPF. The exceptions generally cover buildings appropriate in a rural context (agriculture, forestry), development that maintains a sense of openness (sport, recreation, allotments), infrastructure where openness is preserved, small scall infill and replacement of buildings and housing for local needs.
A further exception relates to the development of homes and commercial development, but only where it utilises grey belt land and can demonstrate an unmet need and would be in a sustainable location. In this situation, housing development must also provide a certain level of affordable housing, deliver necessary improvements to local or national infrastructure and ensure access to good quality green spaces within a short walk of new homes. These expectations are known as the ‘golden rules’.
The identification of land as grey belt may mean that applications come forward on that land.
However, grey belt land is still Green Belt land, and an applicant would have to demonstrate how their application would not fundamentally undermine the purposes of the remaining Green Belt as a whole (essentially purpose (c)), and meet the other exceptions set out within the NPPF. A local authority is also expected to have a supply of land for housing already agreed that meets future unmet need, and speculative applications on grey belt can be resisted on a number of grounds.
Applicants may be incentivised by the introduction of ‘grey belt’ within the broader definition of Green Belt to claim their land is grey belt and help support the case for development.
Completing a Green Belt Assessment is a means of ensuring that a planning authority can address these claims on a clear and consistent basis. The presence of advice across the NPPF, national Planning Policy Guidance and at a local level should also provide clarity to an applicant as to what the expectations are and what the burden of proof is in respect of their application.
A Green Belt Assessment is a technical exercise that tests all of the Green Belt within a defined area – usually a district of borough – against the five purposes of Green Belt, although in the determination of whether land is grey belt, only purposes (a), (b) and (d) are strictly relevant.
The methodology for the Green Belt Assessment is set out in national Planning Policy Guidance (which provides further clarity on how the NPPF should be applied). It advises that the Green Belt should be divided into parcels to aid the assessment. The assessment should consider the contribution that each parcel makes to Green Belt purposes (a), (b) and (d) and where this purpose is strong in any one of these purposes the land cannot be grey belt.
It follows that grey belt can only be defined where land does not contribute strongly to purposes (a), (b) and (d). The national Planning Policy Guidance provides clear definitions and expectations to help the assessment and to ensure consistency across wide areas and beyond local authority boundaries.
The Planning Policy Guidance methodology advises that the number and size of assessment areas can be defined at a local level and respond to local circumstances, but recommends that parcels are sufficiently sized to allow an assessment of their variable contribution to the five purposes. Smaller parcels are expected to be found around existing settlements and around transport hubs. In East Herts, parcels have been defined locally taking into account landform, boundary features, urbanising influences and the strength of the relationships with the countryside and build development.