Infrastructure services company FM Conway has delivered a carbon neutral scheme in Westminster, laying a new road surface containing 92% recycled materials – the highest percentage ever used on a UK road.
Implementing multiple low carbon techniques, the firm achieved a total embodied and operational carbon saving of 78% – equal to approximately 100 tonnes of CO2 equivalent.
The residual unavoidable carbon emissions were then offset using high-quality Verified Carbon Standard (VCS) units, administered and certified by Verra, the world’s largest carbon registry, to make it a one-of-a-kind carbon neutral scheme.
The finished product provided a brand new surface course containing 92% recycled materials, which delivered other benefits in addition to carbon reduction, such as faster installation and less neighbourhood disruption. To achieve the substantial carbon savings, the asphalt material was manufactured at lower temperatures and laid in a thinner layer.
Additional carbon savings were made in the footway construction, through the implementation of FM Conway’s low carbon model, which incorporated closed loop recycling of excavated materials, as well as the use of lower thickness paving materials and lower carbon cement alternatives.
The full scope of works was carried out using no fossil fuels on site. This was achieved through the use of Hydrotreated Vegetable Oil (HVO) in the resurfacing element of the scheme, plus the use of electric mini-excavators, disc cutters and compaction plates, as well as using a solar powered welfare unit which used HVO as a backup in the footways element.
After the industry-leading embodied and operational carbon savings were achieved, the residual unavoidable emissions were offset using high-quality carbon removal and renewable power projects.
FM Conway and Westminster City Council have a longstanding history in pioneering the use of recycled content. A trial to lay an 80% recycled content surface in Sutherland Avenue in June 2019 was followed in 2021 by a warm mix surface course containing 85% recycled content on Third Avenue in 2021, and this latest improvement to 92% recycled content in Elmfield Way represents a further significant improvement in sustainable materials.
FM Conway Sustainability Director, Matt Tallon, said: “This one-of-a-kind scheme illustrates how it is possible to stack together the best low carbon products, methods and techniques that are available today, to deliver massive carbon reductions. It is only once these embodied and operational carbon savings are made, should the residual carbon be offset, which in this case was done with high quality, verified ‘VCS’ carbon removal and renewable projects, as well as the planting of trees in the UK.”
Councillor Paul Dimoldenberg, Cabinet Member for City Management and Air Quality said: “The use of 92% recycled materials is remarkable and a huge step in the right direction as part of the council’s commitment to creating a Fairer Environment. This is only the start of more carbon saving initiatives we’ll be trialling in the city to get us one step closer to hitting our net-zero targets.”
Head of Operations (Highways) at Westminster City Council, Phil Robson, said: “It is a really interesting time to be working in Highways with partners and adapting services to achieve climate resilience and low zero carbon emissions.
“The transition requires the use of offsets at this time but we expect to see lower reliance on them over time. A big thank you to all the excellent engineers that have worked on this project.”
Image from FM Conway