Mainmark Ground Engineering UK is calling for a collaborative approach to housebuilding and further education around the guidelines of ‘grey belt’ land to help protect the UK’s ‘green belt’.
This comes as research from countryside charity Campaign to Protect Rural England (CPRE) found that the majority of homes planned for ‘grey belt’ land, as outlined by the government’s December 2024 planning policy, are actually set to be built on unspoilt countryside.
Sir Kier Starmer described ‘grey belt’ land as ‘poor-quality scrubland, mothballed on the outskirts of town’, as well as previously developed land such as disused petrol stations and car parks, adding a commitment to prioritise its use, under stricter conditions for release, for development.
However, since the policy was introduced, building pressure to meet the UK-wide target of 1.5 million new homes has led to 13 developments of 10 or more homes being approved by government planning inspectors on ‘grey belt’ land in the ‘green belt’. Of the 1,250 homes set to be delivered by these schemes, 88 per cent will be built on previously undeveloped countryside.
Freya Chapman, Residential Lead at Mainmark UK, said: “It is recognised that building on ‘grey belt’ land presents challenges, with its past uses often leaving soil conditions poor, unstable and even contaminated. The impermeable surfaces can also lead to drainage issues and washout.
“However, these issues don’t make such land unusable; it simply requires the correct assessment and long-term solutions, which can be provided through a collaborative approach. By bringing together engineers, environmental experts, planners and developers, the land can be made usable, reducing the need to encroach on green belt areas.”
Further CPRE research shows that England has enough ‘grey belt’ previously developed land for 1.4 million new homes, nearly half of which already have planning permission.
Freya emphasises that action needs to be taken towards these solutions now, as the quick fix of building on green belt land risks long-term consequences, including the loss of quality farmland, important wildlife habitats and land crucial to achieving the government’s 30 per cent nature protection target by 2030.
The vague definition of ‘grey belt’ land has also led to further confusion, highlighting the need for clearer guidance to help protect the ‘green belt’.
Freya continues: “It’s important to invest in research and development – testing soil quality, funding further geological survey technologies, and more education for homeowners, housing associations, property developers, and landlords on grey belt land is essential.
“Once a site is surveyed, methods such as ground stabilisation, drainage and water management, and contaminated land remediation can be implemented, depending on the specific issue, to help mitigate any risks and make the land usable.
“When constructing on grey belt land, foundation design and quality materials are of the utmost importance. A well-designed foundation can help mitigate the effect of the unstable ground by providing necessary support and stability, while quality materials can handle the stresses caused by soil movement, ensuring the foundation remains intact.
“We offer a Screw Pile foundation solution which can be used to create new foundations or to support existing building foundations by transferring a buildings load to deeper more stable soil in a quick and minimally disruptive way using steel shafts and screw-like plates.
“Excavating contaminated soil from grey belt land and either treating it or removing it from the site is often the most widely used method for stabilising the land. However, techniques such as our Teretek® Resin Injection technology offer a method that is both quicker and typically more economical than the traditional excavation and replacement.
“By injecting resin into the contaminated site, which quickly expands and hardens, we can provide rapid stabilisation to the affected area, containing the soil and increasing the load-bearing capacity. The minimally invasive technique avoids large-scale disruption to the site.”
xMainmark UK, part of the Mainmark group of companies, was established in the UK in 2015. Headquartered in Milton Keynes – but with 14 locations across the world – the company is aiming to further its innovative and efficient solutions to a wide array of ground engineering challenges, with Freya at the helm of its residential offering.
