Claire Stafford is a Planning and Policy Advisor at the RTPI
The green belt is one of the most politically contentious topics in planning, yet despite being widely known, the policy is often misunderstood by the public and in wider discourse.
National green belt policy has largely remained unchanged over the decades, but the manner in which it is implemented has altered. This has led to conflict around the way the policy has been interpreted and applied.
The previous Conservative government revised national planning policy at the end of 2023 which acted to de-incentivise the revision of green belt reviews. The new Labour government have taken a more proactive approach to green belt through the introduction of ‘grey belt’, which is discussed further below.
What actually is the green belt?
The notion of green belt is intrinsically linked to Sir Ebenezer Howard’s To-morrow: a Peaceful Path to Real Reform, published in the late 19th century as an argument for the development of garden cities. The concept was developed in the 1930s by the Greater London Regional Planning Committee and by the 1938 Green Belt (London and Home Counties) Act.
At its core, green belt is an urban containment policy designed to function strategically at the city region level. The National Planning Policy Framework (NPPF) sets out the 5 purposes that green belts serve:
- To check the unrestricted sprawl of large built-up areas;
- To prevent neighbouring towns merging into one another;
- To assist in safeguarding the countryside from encroachment;
- To preserve the setting and special character of historic towns; and
- To assist in urban regeneration, by encouraging the recycling of derelict and other urban land.
Green belt covers circa 13% of England’s land area and is clustered around 15 urban cores, with the largest concentration around London, Merseyside and Greater Manchester. London Metropolitan Green Belt is however subject to separate legislation and requirements.
Green belt as a policy designation sits separately to other environmental protections, such as National Landscapes, Sites of Special Scientific Interest and National Parks. As such, designated green belt is not itself a marker of environmental importance, despite common misconceptions. Indeed, a large amount of green belt land is inaccessible to the public and/or in agricultural use.
Recent change in implementation and analysis from different groups
Despite green belt policy largely remaining unchanged, its implementation has transitioned from a strategic policy tool applied strategically, to a strategic tool applied locally since 2010 due to the abolishment of regional plans.
There has therefore been a move towards individual authorities seeking to ‘protect’ their own parcel of green belt, rather than thinking of green belts at a higher spatial scale. This has subsequently led to litigation over differing interpretation and application.
In addition, there is ongoing debate around the role of green belt in relation to plan making and housing delivery; campaign groups such as the Green Alliance have called for new homes to be focused in sustainable locations and Centre for Cities champion green belt releases around existing commuter train stations. The Adam Institute recommended more aggressive measures including the abolition of the green belt, whereas CPRE instead call for further protection of green belt and for policy to embrace its role in tackling the climate and nature crises.
Recent proposals from the government
The grey belt
As part of their growth agenda, Labour have placed great importance on house building as a pivotal economic driver. Key to this initiative is the new concept of the ‘grey belt’, that has been proposed as a more “strategic approach to greenbelt land designation and release to build more homes in the right places”. In practice, grey belt will not function as a designation, but rather as a process, as explained in the next section. We recently discussed whether the introduction of the grey belt is a good thing.
In our response to Question 23 of the recent NPPF Consultation (RTPI, 2024), we supported the proposed definition of grey belt land which largely relates to the green belt’s five purposes, rather than the aesthetic or amenity value of land. This maintains an emphasis on the green belt’s core objective of urban containment.
In our consultation response, we welcomed additional guidance around land which makes a ‘limited contribution’. We also cautioned that the quality of green belt land should be benchmarked to a point before the government’s announcements regarding ‘grey belt’ were made in spring 2024. This would remove the incentive for landowners to allow it to degrade.
A sequential approach to development
Labour have confirmed that local planning authorities (LPAs) must work to meet their housing need through a presumption in favour of brownfield development in the first instance. Consideration must then move to grey belt land, and, then, finally as a last resort, green belt land.
We support this sequential approach to guide the release of land in the right places so that low quality green belt land is identified first. However, given the number of sites that make a limited contribution to the purposes of green belt, and how many LPAs are likely to struggle to meet their housing need with brownfield sites, we feel it is necessary for Government to add in an explicit requirement for sites to be in sustainable locations taking into account local infrastructure. This will be crucial given the high degree of LPAs that will be operating under the presumption of sustainable development after having run out of allocated sites.
We also welcome the proposed ‘golden rules’ to ensure communities and nature benefit from green belt release, albeit LPAs should be able to set their own percentage target for affordable housing based on local viability.
What we think overall
The RTPI’s four principles for green belts are as follows:
- Green belt policy should retain its original focus on urban containment, and the implementation of grey belt should reinforce this.
- Green belts should be managed through strategic planning/strategic reviews, as housing targets can only be worked out strategically in the longer term.
- All types of development should be treated equally in relation to green belt release. Without employment, commercial, logistical, and infrastructure developments, new housing may be unsustainable.
- Ultimately, it is reasonable to build on green belt only if this is the only way authorities are able to meet their increased housing targets and they would not be able to achieve this otherwise. This should be implemented through a sequential approach to green belt release.
