Setting the standard for ‘reuse and recycle’ at One Exchange Square in London

Sweco contributors: Matthew Mapp, Monika Potomska, Liva Balode. Images: Secchi Smith studio/Fletcher Priest Architects

One Exchange Square centres around the reimagining of an existing, post-modern office building as it seeks to become a contemporary and sustainable workspace in one of London’s liveliest districts. Bringing together some of the world’s leading sustainability, wellbeing and technology assessment experts, it is aiming for the highest performance targets and setting standards for future builds.

With the UK Government’s target to reach net zero carbon emissions by 2050, One Exchange Square is ahead of its time, being one of the first retrofit projects in London aiming to achieve net zero carbon.

Matthew Mapp, Head of Buildings Whole Life Carbon at Sweco UK & Ireland says: “What we’re seeing is that there’s a real and tangible move towards retaining as much as possible when clients approach us – particularly with the increasing understanding that a lot of the carbon in buildings is located in their structures and façade.

The movement to retaining those elements has come more to the fore not just within the built environment industry, but also from wider spheres of climate change activism and people from other parts of the planning ecosystem who are rightly pushing that agenda as central – rather than additional or even optional – to developments.

The really important thing here is that balance is critical. Although you retain a lot of embodied carbon by saving buildings themselves, if you don’t make significant interventions on the operational sides, and particularly in the façades and the building services, you can actually end up in a worse position overall. Happily, we’ve been able to ensure the perfect weighting of the two in this instance.”

Monika Potomska, Sweco’s Senior Sustainability Consultant adds: “The not-so-secret recipe in achieving circular viability as well as a balance between embodied carbon and operational efficiency is early involvement. Truly holistic analysis can only be undertaken at a stage when we can still make significant impact and shape changes to a design.

Once you go through planning and you get to the later stages, it’s much harder to post-influence the direction of travel when it comes to sustainability.

Lasalle Investment Management and our wider partners on One Exchange Square have been exceptional not only in their vision, but also in their understanding that the most effective and transformational collaboration starts at the start.”

We pride ourselves on being an industry leader in ESG best practices. We weave sustainability into our operations at every touchpoint across our European business…at the centre of this commitment is our pledge to deliver net zero carbon buildings by 2050.

LaSalle Investment Management

Matthew continues: “That’s exactly right. For example, my main tasks only form one part of a whole raft of the sustainability piece, which other skills across Sweco feed into. By aligning and challenging each other at the beginning, we fully understand the client brief and can see the expectations of the project.

We of course then know what to price and what to scope. But more importantly we can push boundaries and stretch our own targets to really make a meaningful difference to both the client and their end-users. For example by including BREEAM Outstanding markers, carrying out complete Whole Life Carbon analysis and stress-testing net zero viability from the word go, versus trying to force-fit everything at a later date which can of course bring with it costing and timing implications.”

Monika’s fellow sustainability consultant at Sweco, Liva Balode reflects on the close partnership built across the pool of wider experts on the project, as well as the intrinsic nature-based solutions woven into the fabric of the redevelopment: “This was a really rewarding project. The whole process of façade optimisation took many months, which meant lots of opportunity for collaboration with M3, Fletcher Priest and Heyne Tillet Steel – who were very forward-thinking and receptive to our ideas and guidance. Even down to the quick phone calls on small details, I think it’s been a tremendous team effort all the way through.

I see it as a privilege to be able to boost the urban greening element of this lively location, and look forward to seeing something special to quite literally grow within the ecosystem of London’s built environment. The dedicated spaces for the end users to not only work in but relax in will set One Exchange Square apart from a functional point of view. It’s the biodiversity and wellbeing aspects, however, that we’ve been able to engineer into the DNA of the reimagined building that I’m most proud of.”

With new, more dynamic interior layouts, additional green terraces, green roofs and improved provision of cycle facilities, an exciting and healthy environment is created to enrich people’s experience and the local urban ecology. A greater sense of community is established by creating a link between Bishopsgate and the newly designed park in Exchange Square, enhancing a sense of belonging and wellbeing.

Liva adds: “There are multiple arms of analysis in a project like this, and the one thing that most people don’t get right is operational and embodied balance. That is what we’re proud and excited to have brought to this project in particular.”

This project furthers our commitment to minimising embodied and operational carbon through extensive reuse and enhancement of three quarters of the existing façade whilst creating an intelligent envelope design to the Exchange Square façade presenting a new face to the City.

Fletcher Priest Architects

Whole Life Carbon Analysis – the key to added value

In addition to elements of the existing façade being reused (with any replacements designed to provide another 25+ years of building life), the majority of extensions will be steel and concrete which are materials with known durability in excess of design life. The planning grid also sets the framework for modular components, simplifying replacement or rearrangement in future scenarios.

Matthew reflects: “On the size and scale of this project, you would expect any consultant to push circular methodology. But the uniqueness of the way we approach circular economy at Sweco is that we layer reuse and repurpose viability with our Whole Life Carbon assessment.

There’s no real push to do WLC assessments on a refurbishment building because there is already an expectation that adaptive reuse or repurposing a building is going to be better for the climate. We’re constantly chasing the best outcomes though, and the only way to achieve those is by thoroughly analysing carbon to ensure it the utopia of embodied/operational balance.”

In summary, One Exchange Square applied several circular design principles to optimise its operation, and reduce emissions and operational costs. Every design feature has been carefully considered from materiality to water to energy usage, ensuring longevity, adaptability, reusability and recoverability.

To discuss end-to-end building sustainability, carbon management or any aspect of circularity in future projects please contact our experts below.