Insight: Around 300,000 houses could be delivered on the ‘Grey Belt’

Picture of Harry Quartermain

Harry Quartermain
July 5, 2024
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The Labour Party has formed a new government of the United Kingdom. Among the many pressing issues highlighted during the short election campaign, housing policy emerged as a particularly significant concern. In April, Labour laid out their blueprint for tackling housing shortages and sustainability concerns, which focused on building on 'ugly' parts of the Green Belt land - now coined as the “Grey Belt”.

Releasing any land in the Green Belt has proven to be an emotionally (or politically) loaded topic. At Housing 2021, we presented our own analysis, which showed that if we released just one per cent of the Green Belt we could deliver a year’s worth of new housing (over 300,000 homes at a generous 41 dwellings per hectare). You can read that analysis here.

Following on this research, and what Labour has initially proposed for the Grey Belt, we took the liberty of conducting another preliminary analysis to understand the housing capacity the Grey Belt might offer. Our research has indicated that approximately 300,000 homes can be delivered on sites that might fall within the definition of Grey Belt - a similar finding from our original research on the Green Belt.

In this blog, we’ll dive further into this element of Labour’s proposed housing policy and take a look at what our early research indicates could be possible in terms of housing delivery on the Grey Belt.


What is the Green Belt?

Green Belt is one of the most widely known, but least understood, planning policies in the country. Covering 12.6% of the country, far from being wilderness or publicly accessible open space, the Green Belt is actually a policy focussed on constricting urban growth and protecting the ‘openness’ of the countryside. 

While most of the Green Belt is agricultural land, some sites with the Green Belt are not as ‘green’ as the public might imagine. Former storage yards, disused quarries and petrol stations, car parks and caravan parks are common in the areas around our biggest towns and cities - and all of them enjoy the same policy protections as the greenest of the Green Belt sites. 

Being located around our major towns and cities, these sites are located in some of the most sustainable locations, with access to existing local amenities, employment areas, and transport options. 

A promise to look sensibly at sites within the Green Belt is one of the points of difference between the two main parties in the 2024 General Election, and is likely to be one of the reasons for the Westminster sea change.


Labour's housing policy

Labour campaigned on a promise to build 1,500,000 houses over the five year parliament, which means they would need to average out 300,000 per year.  While this is consistent with the former Conservative government target, expressing this number as an average over the whole term of the parliament allows Labour to ramp up delivery from the current levels that are well below the magic number of 300,000 per year.  We looked in more detail at Labour’s housing and planning policies here


Defining the Grey Belt

Labour’s policy about Grey Belt includes the following statements:

Will Labour build on the green belt?
Labour will not build on genuine nature spots and will set tough conditions for releasing green belt land for house building so that building more homes and protecting nature go hand-in-hand.

Labour is committed to prioritise building on brownfield land first, but we can’t build the homes that Britain needs without also releasing some greenbelt, including poor-quality land, car parks and wastelands currently classed as green belt. 

We will make improvements to existing green spaces, making them accessible to the public, with new woodland, parks and playing fields.

What is the grey belt?
The term ‘grey belt’ refers to neglected areas such as poor quality wastelands and disused car parks that are in the greenbelt. These are places that we could build one, whilst we improve and protect genuine nature spots.

Labour is not alone in recognising this distinction: the Chair of Natural England has called for green belt release to support the housing crisis, noting there is no inherent trade-off between building homes and protecting nature.


Labour has also previously delivered the "five golden rules for house building", which are the following:

1. Brownfield first
Within the green belt, any brownfield land must be prioritised for development.  

2. Grey belt second 
Poor-quality and ugly areas of the Green Belt should be clearly prioritised over nature-rich, environmentally valuable land in the green belt. At present, beyond the existing brownfield category the system doesn’t differentiate between them. This category will be distinct to brownfield with a wider definition.  

3. Affordable homes
Plans must target at least 50% affordable housing delivery when land is released.

4. 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. 

5. Improve genuine green spaces
Labour rules out building on genuine nature spots and 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.


It’s certain that, as the new government moves into Downing Street and Angela Rayner and Matthew Pennycook grow into their new brief, there will be some more meat put on the bones of this housing policy. The incoming Chancellor, Rachel Reeves, has already promised a new NPPF within the first few weeks.  


How many Grey Belt sites are there? 

Using the information that we have at the moment, we have run some analysis about likely Grey Belt sites, their location, and potential development capacity. This analysis has suggested that, using Grey Belt alone, around 300,000 homes - that is one whole year’s housing supply - could be delivered. 

Clearly there is no Grey Belt dataset, so to establish a proxy for this we have tried to identify registered brownfield sites, and vacant or derelict sites that are located within the Green Belt and adjacent to existing roads and built-up areas. 

To run this analysis, we have looked at the location of the existing Green Belt using data from DLUHC. Then, using LandInsight, we looked at Brownfield Land Register data (compiled by using data from local authorities), and also identified vacant or derelict sites using data from Ordnance Survey and HM Land Registry. 

In order to focus this exercise on sites that are most likely to come forward, we have limited our analysis to sites that are adjacent to roads and built-up areas, as this rules out the most isolated sites. We have also ruled out sites that are significantly affected by flooding, or protected as SSSIs, Priority Habitat, Nature Reserves, Common Land, Ancient Woodland, Best and Most Versatile (BMV) agricultural land, or scheduled ancient monuments.  

Development assumptions

To get an understanding of the development capacity of these possible Grey Belt Sites we’ve applied a margin of error to the total area of land on the sites that we have identified. We’ve also applied some high level development assumptions (60% site coverage to allow for some Biodiversity Net Gain to be delivered on site, and density of 50 dwellings per hectare - on the basis that most of these sites are located on the edge of settlements). 

This analysis has returned the following:

Grey Belt Data Image (1200 x 800 px)


What’s next?

Green Belt Policy is a Local Plan policy - as such the changing of the guard in Westminster won’t deliver an overnight change of Green Belt policy.  Local Authorities will still need to be incentivised to deliver new local plans, and to use these plans to review their Green Belt boundaries. We will keep track of how this develops as the expected new NPPF will be released in the next few weeks. Once there is more information about what Labour actually means by Grey Belt, we will update this analysis. 

In the meantime, if you’re looking to identify and assess sites that meet your particular development requirements, request a demo below to speak to one of our experts about using LandInsight. 

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