Current national green belt policy is set out in chapter 13 of the NPPF.  This sets out the fundamental aim of green belt policy: To prevent urban sprawl by keeping land permanently open.

The NPPF identifies that the essential characteristics of green belts are their openness and their permanence.  Recognising that the general extent of green belts across the country is already established, the NPPF advises that there is no requirement for green belt boundaries to be reviewed and that authorities may choose to review and alter the boundaries only through the plan-making process where exceptional circumstances are fully evidenced and justified.

Under current green belt policy, subject to very limited exceptions, development on land designated as green belt is regarded as inappropriate and should only be granted planning permission in very special circumstances.

The starting point for further consideration of the new Government's proposals is the Labour Manifesto.  In the context of green belt release, this stated that the priority should be "the release of lower quality 'grey belt' land".  There is no explanation as to what is meant by 'grey belt' land and, of course, this term will be critical if it proves to be anything more than electioneering short-hand and is to be formally introduced into national policy.

On the face of it, there is the potential for Labour's proposals to result in a complete redefinition of the green belt, depending upon whether the concept of 'grey belt' land is formalised in the NPPF and how wide its definition ends up being.  For example, it could be limited to previously developed land in the green belt or it could be more widely defined by reference to qualitative factors such as landscape value.  In other words, it is possible that the quality of the land as landscape/countryside could be introduced as a factor in the designation/release of land (whether as green belt, grey belt or otherwise).  

Given that the long-standing function of the green belt (as encapsulated in the present NPPF) is to prevent urban sprawl by keeping land permanently open, the introduction of such an additional consideration would be a major policy change.  However, Labour's Manifesto indicates that it is, "committed to preserving the green belt" and that it does not intend to change, "its purpose or general extent".  If the purpose of the green belt is not to change, we can reasonably conclude that the release of grey belt will be restricted to land where such release does not impact on the overall function of the green belt.  Through this lens, suddenly Labour's Manifesto pledge looks more like a tweak to existing policy, rather than something more revolutionary.  

Wrapped into this is also the question of whether this is purely about the designation and release of green belt or whether there will be any corresponding changes to the NPPF policy controlling development in the green belt (e.g. by redefining what constitutes inappropriate development to allow development on 'grey belt' land).    Only the latter would have any immediate impact in terms of potentially unlocking development in what is presently green belt land.

Given that the new Government is keen to make an immediate impact with its reforms, in addition to changes concerning the designation and release of green belt, we would expect some kind of corresponding change to the development control aspects of green belt policy in the NPPF to make it less restrictive for 'grey belt' land.  In the absence of any further detail from the Government at this stage, we will have to wait and see if this proves to be the case.  Since the Government proposes to publish a revised NPPF within its first month in office, we should not be waiting too long.

There are a number of additional matters that we consider the Government should also be giving thought to in the context of green belt reform.  Specifically:

(1) Critical National Priority (CNP) Infrastructure

The concept of CNP infrastructure was introduced into the Energy National Policy Statements (the Energy NPS) adopted in January in recognition of the urgent need for new low carbon energy infrastructure to deliver the Government's energy security and net zero ambitions.  It covers various forms of low carbon infrastructure and includes electricity grid infrastructure.

The CNP policy influences how the Secretary of State considers the planning balance for CNP infrastructure and whether certain policy tests are met.  Under the policy, where the Secretary of State is satisfied with the applicant's assessment, CNP infrastructure benefits from certain favourable presumptions, including in relation to green belt policy.

As such, the CNP policy in the Energy NPS represents a specific loosening of the green belt (and other policy) to facilitate the delivery of CNP infrastructure.  At the moment it only applies to Nationally Significant Infrastructure Projects.   However, there is no sensible reason why the policy should not be extended to CNP infrastructure that requires planning permission, i.e. for the CNP policy to be incorporated into the NPPF.  

In view of the Government's growth mission (which includes speeding up infrastructure delivery and prioritising energy infrastructure), this would be a potential "quick win" revision to the NPPF.

(2) Mandatory Biodiversity Net Gain (BNG)

Since 2 April 2024, all new planning applications pursuant to the Town & Country Planning Act 1990 in England have been subject to the mandatory BNG regime introduced by the Environment Act 2021 [1].  Subject to limited exceptions, this requires new development to deliver at least 10% BNG.

There is no suggestion that the new Government intends to change any aspect of the BNG regime, which is in any event still bedding down.  However, by its very nature, the BNG regime results in the ad hoc delivery of BNG land, which is required to be legally secured and registered as such for a minimum of 30 years.  

There is an inherent danger with this system that, over time, a new unplanned "belt" of BNG land may inadvertently develop in some areas.  Since this would be of an even more restrictive nature than green belt, this could undermine any loosening of green belt policy in the long term.  Whilst this may not be something for the next iteration of the NPPF, there is an opportunity here for the new Government to provide some early strategic direction to get ahead of this risk.

(3) Statutory green belt

Finally, there is the long forgotten statutory version of green belt introduced by the Green Belt (London and Home Counties) Act 1938 (the 1938 Act).  

Predating the modern town and country planning system, the 1938 Act was intended to establish a form of green belt around London via a system of covenants and restrictions.   However, it has effectively been superseded by the development plan-led town and country planning system first introduced by the Town & Country Planning Act 1947 (which enabled land to be designated as green belt for the purposes of the development plan) and the national Green Belt planning policy first adopted by the Government in the 1950s and now contained in the NPPF.

Notwithstanding this, the 1938 Act remains a firm fixture on the statute book. Land designated under the 1938 Act remains subject to the legislation, which is archaic, restrictive and cumbersome to navigate in practice.  Given that most, if not all, of such land will have since been designated as green belt for the purposes of the planning system, there is no continuing need for this statutory version of green belt.

In light of this, there is an opportunity here for the new Government to simplify matters for developers around Greater London – first by amending the NPPF to require those local planning authorities affected by the 1938 Act to consider the status of any land designated under that legislation as part of any green belt review, then by simply repealing the 1938 Act.

[1] Please see our summary of the BNG regime here