Recognising that we can only achieve our ambitious 2030 sustainability targets by working with others, we’re asking supplier partners across our portfolio to share their thoughts and experiences. Here, Kathryn Weatherburn of Sir Robert McAlpine reflects on how collaboration and innovation at 2 Finsbury Avenue are accelerating net zero carbon and circular economy progress.

Kathryn Weatherburn, Senior Sustainability Manager at Sir Robert McAlpine

2 Finsbury Avenue is our latest project at Broadgate. Taking lessons from earlier British Land projects and innovating, the whole team is doing everything possible to achieve the best outcomes.

It's really exciting to be part of a project that’s leading the way. 2 Finsbury Avenue is targeting high sustainability ratings, including BREEAM Outstanding, WELL Platinum and NABERS UK 5-star. We have tried to maintain the same standards in construction, demonstrated by our score of 49/50 on our latest Considerate Constructors Scheme assessment, rated ‘Outstanding’ for environment, community and workforce.

Advancing towards decarbonising buildings

At the final design stage of this project, we were able to reduce the embodied carbon emissions from 755 kg CO₂e per sqm to of 656kg CO₂e per sqm.

British Land involving us as main contractor at an early stage brought benefits, as we were able to engage with the wider supply chain to improve design efficiency and propose innovative low-carbon materials.

In partnership with our piling contractor, we rationalised the foundation design, reducing pile diameter from 2.4m to 1.8m to optimise material use and used steel manufactured in an electric arc furnace for around a third of the plunge column piles, which cut embodied carbon by 15%. Together, we have also pioneered basalt reinforcement in the temporary works. Made of volcanic rock, this is up to 60% lower carbon than steel reinforcement in its manufacture.

Working with the steelwork contractor, we’re using 95% XCarb steel in the superstructure; a product which is manufactured by electric arc furnace with 100% recycled steel and powered by REGO-backed renewable energy, saving around 5,000 tonnes of CO₂e versus traditional blast furnace steel. The façade features aluminium produced using renewable power, saving around 1,900 tonnes of CO₂e versus an average European aluminium product.

We’re also powering site equipment with Hydrotreated Vegetable Oil (HVO), moving away from fossil fuels and lowering emissions wherever possible.

Accelerating circular economy

Before deconstruction started, British Land commissioned an audit to identify existing building materials that could be salvaged, stored and reused. Our conversations with subcontractors are changing, in how they look at materials on site, promoting circular economy principles.

Nearly 25 tonnes of structural beams were extracted, cleaned, tested and are in the process of being warrantied for reuse. Approximately 2,500cbm of concrete was recovered, crushed and reused in the foundations, reducing embodied emissions and lorry movements on local roads. Around 9,500sqm of raised access flooring was also removed and stored for reuse, following successful pilots on earlier British Land projects, where refurbished tiles perform ‘good as new’.

Leading on sustainability

As Sir Robert McAlpine progresses our own pathway to net zero by 2045, we’re taking lessons learnt from 2 Finsbury Avenue to other projects – from design efficiencies to new innovative materials such as basalt reinforcement. British Land’s stringent requirements have also improved how we collect, review and report carbon data and ensure its accuracy.

British Land is leading on sustainability – setting ambitious targets, collaborating with the supply chain and constantly pushing the boundaries. Working with a forward-thinking client, we’re able to have conversations about innovative low-carbon solutions, knowing that British Land will listen and is open to investing where needed.