After making our Circularity in Practice commitment, The Acre – a ‘retrofirst’ transformation of a 240,000m3 icon in London’s West End allowed circular economy principles in engineering to take centre stage. With goals to become a sustainable mixed-used space, circularity was designed into the scheme from its foundations.

Commit

Being invited to participate in the development of the ReCirculate project, our team were determined to showcase how construction can make meaningful change through innovation in the built environment.

His Majesty The King’s initiative is a pathway to take ideas from blueprint into buildings that advocate for circularity from the inside out. Using our specialist knowledge in engineering, we are determined to find opportunities to incorporate circularity into the construction industry through retrofit projects that are becoming necessary as London continues to transform.

Plan

Circularity drove the rebirth of a Brutalist relic, with ambitions to retain the majority of the structure and create reuse opportunities through carefully engineered temporary works, drastically reducing steel and reusing existing materials.

Our in-house construction engineering team assumed a consultancy role with the client team from the earliest stage of their project, crafting a high-value solution characterised by substantial programme savings and exceptional carbon reductions.

A critical aspect in taking circularity off the page and into the project was the successful temporary division of the interlocking buildings into two independent structures during demolition before reconstructing the linking units. Retention relied on stability, needing innovative engineering and construction sequencing for success.

To retain over 80% of the original structure, we devised a radical scheme to simplify demolition and construction. The plan included roof-top cranes and reducing the reusable horizontal propping to a single level of only four steel props, reducing the embodied carbon by half compared to previous build proposals.

Partner

Understanding how a circular economy approach could deliver the project’s ultimate goals was achieved through a close partnership with our clients at Platform. Being relationship-led and communicating opportunities from the outset, proper planning and expectations could be laid to deliver certainty of success.

Reversing the supply chain is a key part of evolving and delivering our Circular Economy Strategy. We engaged with RMF, our supply chain specialists, to provide a platform that enabled salvaged materials to find a new home with second-hand buyers.

Meanwhile, early engagement allowed our team to work closely with the client and our partners at steel manufacturer Westok. By engaging vertically through our supply chain, we manufactured the McGee-specified innovative reusable propping solution – the signature ‘big yellow props’ – that slashed carbon through championing reuse principles.

Act

The project exemplified circular construction solutions. Alongside championing the reuse marketplace, our reusable propping system enabled the retention of the structures, reducing the intensity of new materials by 88% from the reference scheme.

Utilising a reuse marketplace, we were also able to return 12,000 Raised Access Floor tiles for refurbishment and resale to the market. The retrofit also championed steel reduction and maximised reuse, helping the project achieve its goal of WELL Platinum and further embedding circular economy principles into ongoing construction practices.

Share

A whitepaper detailing the innovative scheme was awarded the Coopers Hill War Memorial Prize at the Institution of Civil Engineers Publishing Awards. The scheme also went on to win the British Construction Industry Award for Temporary Works Initiative of the Year. These awards prove to industry leaders that engineering from circular economy principles can enable retrofirst projects to get off the ground.

Pledge

We’re working to facilitate innovation throughout the construction industry. It means collaboration throughout each phase and instilling an appetite for sustainable innovations that can drive the built environment further in its sustainability ambitions.

Change comes from collective effort across the entire value chain. It means working with clients, local authorities, residents, and suppliers to ingrain reuse and sustainability as default in the built environment.