What is the 'grey belt' and how many homes could Labour build on it?

A planning system overhaul has been unveiled by Deputy Prime Minister Angela Rayner as part of the new government’s pledge to deliver 1.5 million homes over the next five years.

Under the plans, some low-quality green belt land will be freed up to become part of a 'grey belt' to allow new homes to be built.

The government has previously described the grey belt as "poor quality and ugly areas" on parts of protected land, called the green belt.

Established more than 70 years ago, the green belt covers about 13% of England. It was designed to limit the growth of large built-up areas, and to stop large towns merging into one another.

Under the Labour government's plans, if a council's housing targets cannot be met some existing green belt land will be re-designated as grey belt. This will free up land for the construction of new homes.

New rules will require half the dwellings built in the grey belt to be affordable homes.

Labour has previously pointed to a disused garage in Tottenham, north London, as an example of a green belt site that cannot be developed into housing because of its designation.

The government's definition of the grey belt includes land on the edge of existing settlements or roads, as well as old petrol stations and car parks.

Under the current rules, it is very hard to build on the green belt. Applicants need to demonstrate very special circumstances to justify planning permission.

The government also says that brownfield sites - old industrial or already built-on land - should be prioritised over the grey belt.

As the grey belt will be a new category, there is no official data on how much of it exists.

However, estate agent Knight Frank has previously carried out its own analysis.

It has identified 11,000 previously developed sites, making up less than 1% of the existing green belt.

The sites are mainly concentrated in the south of England with just over 40% within the London green belt area.

In total, 100,000-200,000 new family homes could be built on the sites according to Knight Frank.

Nevertheless, Sam Stafford from the Home Builders Federation believes that building on both the grey belt and additional brownfield sites in urban areas will be necessary to meet England’s housing needs.

"There just isn’t the land within major towns and cities to meet the housing need in its entirety," he said.

To support his claim, Mr Stafford points to a 2022 report by planning consultancy Lichfields which found that even if every identified brownfield site in England was built to its full capacity, that would mean 1.4 million extra homes.

That is less than the housing target of both major parties ahead of the election. Labour pledged 1.5 million new homes in England and the Conservatives 1.6 million.

Labour says the grey belt developments must offer 50% affordable housing. This includes homes that are let at least 20% below local market rents.

However, Charlie Hart from Knight Frank says this could be hard to achieve as inflation has significantly pushed up costs for developers.

Katie Townsend from the Centre for London think tank says that although the plan is for grey belt homes to be built by private developers, the government should consider stepping in.

“The best way to ensure affordable houses are built, particularly socially rented homes, is to increase government investment”, she says.

Labour floated the idea of creating the grey belt long before the election.

When Sir Keir Starmer mentioned it over a year ago, then prime minister Rishi Sunak ruled it out as he "wanted to make sure our green spaces are protected".

Building on the green belt is controversial.

However, Ms Townsend of the Centre for London says attitudes might be shifting, pointing to polling showing half of Londoners supported building strategically on low-quality areas of the green belt, with only 19% against it.

Others disagree. Countryside charity CPRE Oxfordshire, for example, says land is "already under enormous pressure".

Its director Helen Marshall says: "Ten years ago we commissioned research which showed that over 70% of Oxfordshire wanted the green belt to remain undeveloped.

"Ten years later support for the green belt has increased to over 80%."

However, Mr Hart of Knight Frank says that while the green belt used to be seen as a "don’t go zone", perceptions are shifting.

"It was conceived a long long time ago and the world is a very different place and we’re now reviewing whether it’s fit for purpose in the modern world."

Additional reporting by Gerry Georgieva