Net Zero firm proves to be the ‘wheel deal’ for MOD

Viridis Building Services, based in Collingham, near Newark, was approached by the Ministry of Defence to create a new carbon-neutral training centre at its rebuilt training base in Beckingham, Lincs.

The firm, one of the first net zero companies in the UK, looked at future sustainability for the project.

Viridis realised that the MOD disposed of thousands of tyres each year from its huge fleet of vehicles, so set about devising a way of incorporating old tyres into the rebuilding of the 1940s cadet training centre.

A method was arrived at to create pillars out of recycled tyres as the base for the foundations of five accommodation buildings and a large mess hall. Each ‘pillar’ was then to be infilled with recycled crushed aggregate.

The ground-breaking idea, which has never been used in a commercial environment in the UK before, has reduced the potential concrete usage on the site by around 85 per cent, further benefiting the environment and the sustainability of the project.

Lee Marshall, managing director of Viridis Building Services, said: “Our task was to achieve net zero without breaking the bank and meanwhile impacting as little as possible on the environment.

“Using recycled tyres as foundations instead of tonnes of concrete is one solution, though it was significant that there are local sources which can supply the old tyres.

"This, combined with the enormous environmental and financial cost of manufacturing, transporting and pouring concrete, really put the wheels in motion for achieving our net zero brief.”

Lee estimated that the British Army saved more than £80,000 alone by using recycled tyres instead of concrete at the new Beckingham Cadet Training Centre, which is scheduled for completion in spring 2025.

It also meant that far less ground needed to be dug out and removed, helping to protect the ancient ridges and furrows on the site, which are the remains of farming methods dating back to Anglo-Saxon times.

The building foundations are being created by digging piles around six metres apart, each the diameter of the stack of recycled tyres. Once the centre of the tyres is filled with a fraction of the aggregate and concrete that would otherwise have been required, the 12-metre by 36-metre building frames are placed on top.

Viridis provided several additional solutions for the project to ensure its net zero ambitions.

These included the use of sustainable materials, such as timber frames for the buildings and the creation of low-impact walkways between the buildings to further avoid excessive ground disturbance.

To avoid the mess hall overheating without over-investing in solutions such as building reinforced concrete walls, Viridis recommended the positioning of Gabion walls – effectively rocks held within a metal cage – on the south-facing elevation of the structure.

Gabion walls have been proposed to the front of the main building. This will have a further knock-on benefit of this inexpensive “air conditioning” method is that the four-to-six-foot walls provide the mess hall with a means of overheating protection.

Lee added: “What we’ve learned on the Beckingham Cadet Training Centre project is hugely valuable in terms of decarbonisation on a really affordable level. The recycled tyre foundations certainly set a benchmark and are perhaps something that the MOD can look to roll out at other bases in the future.”