Materialising circularity
The Brent Cross Town substation is critical to this London borough’s net-zero carbon ambition. Ben Glover of Arup wraps up the development of the largest permanent public artwork in the UK.
The built environment is at the intersection of several competing pressures. We live in a post-pandemic world, in the wake of geopolitical tensions, as well as the increasingly evident consequences of climate change every day.
As industry actors, we face interconnected challenges related to the transition of energy and industrial materials to achieve net-zero targets, going against the grain of a linear economy that continues to dominate all industries.
Needless to say, these factors are also complex, posing their own individual issues and opportunities that require careful consideration and balance. This can especially be said for specific raw materials required for low-carbon innovations.
It is our responsibility to provide clarity and prioritise progress in all that we deliver, whether that be through the innovation we bring to life through our work, or the technical information and initiatives we share with our audiences.
As an industry, we know that the global built environment accounts for 39% of all carbon emissions and that cross-sector net-zero ambitions require us to take dramatic action in how we approach and operate within our urban landscape, specifically around our engagement with resources including steel and concrete.
We also know that we have the capability to deliver on decarbonisation and biodiversity targets, but the change we need to mobilise requires viewing and interacting with our resources differently.
Prioritising circularity is increasingly crucial, and rethinking how we retain virgin materials’ value is now an absolute imperative to infrastructure design. In the knowledge that we are now borrowing resources from future generations, we have a responsibility to be creative and collaborative with our solutions to enable circularity in decades to come by supplementing and conserving the materials used today.
Progress is being made as our industry explores opportunities to retrofit buildings and restore materials more than ever before.
The challenge is to bring these forward-thinking schemes and initiatives further into the mainstream. To do so, it is essential that we unlock cross-sector collaboration in the delivery of large-scale, landmark projects that truly make a difference.
If not approached collaboratively with all project stakeholders, these components could be considered as conflicting criteria to growth – the glue that binds this interconnected thinking together is organisations stepping beyond their identified roles and scope of any given initiative to bring true innovation and sustainable development to fruition.
Circular Buildings Toolkit
We are only just beginning to tap into the possibilities technology can provide. Digital tools and technological advancements will help overhaul the linear economy.Arup’s partnership with the Ellen MacArthur Foundation is an example of a collaboration to strategise and deliver such innovation, supporting others in the industry with achieving our collective sustainability and circularity goals.
Together we have developed the Circular Buildings Toolkit (CBT) – a digital tool to support all those in the industry, from urban designers to asset owners involved in the redevelopment process. The toolkit was imagined to alleviate the approximate 95% of construction material value lost to demolition by designing out waste and pollution with the right strategies.
In a similar process to that undertaken when reimagining Brent Cross Town substation, the toolkit enables us to build efficiently and deliver longer-term value.
The construction process is more multifaceted than ever – digital frameworks such as the CBT can remove some of the integrated complexities, giving the opportunity to maximise and deliver a project’s sustainability ambitions. Examples of this could include better understanding of where certain materials have originated from, and how they have been refurbished thus far, or how certain design elements can be disassembled and reused elsewhere, extending a building fabric’s lifecycle.
A new piece of city
A recent example of this in action is the primary substation at London’s Brent Cross Town redevelopment. Building on Arup’s work with Argent to redevelop Coal Drops Yard in London’s King’s Cross, we were part of the collaborative team that converted this derelict brownfield site in Brent Cross into a sustainable, artistic piece of infrastructure, forming an integral element of one of Europe’s largest regeneration projects worth £8bln.
Upon completion, the substation will generate electricity for a new community of more than 6,700 homes, over 270,000m² of offices, and new retail and leisure space.
Also serving as the largest piece of public artwork in the UK, it was prioritised from the outset that the substation would be more than the sum of its parts. The design is a symbol of circular principles and material value retention in its simplest form.
By providing a talking point to generate economic interest and social value throughout the area as it was redeveloped, it was collaboratively decided to showcase the substation with art and colour, enabling it to go beyond its utilitarian functionality.
Now wrapped in a renowned piece of kaleidoscopic artwork and taller than the Angel of the North in Gateshead, the infrastructure is located beside both the M1 motorway and adjacent to Thameslink railway lines. Each year, six million people will see its colour and creativity from transport modes alone, speaking to the beautification aspects of the infrastructure’s redesign.
Reimagining materials
Related Argent appointed Arup to bring together a multidisciplinary team from across the firm, as well as engage with other industry experts to deliver its vision of a net-zero substation – simultaneously shaping a modern landmark for London.
Architects IF_DO, contractor Galldis and structural steel specialists Bourne Group all contributed to the removal of linear economy principles and minimising carbon impact.
The reuse of steel is central to the project’s sustainability credentials. To identify and procure the appropriate steel for reuse, Arup’s experts engaged with Cleveland Steel, Europe’s largest stockholder of steel tubing. By using specific industry knowledge and Arup’s experience in circular construction, 42.5% of structural steel was recovered from old and unused oil pipelines. In turn, this reduced the embodied carbon of the project’s steel frame by over 40%, saving 99.2t of CO₂e.
Arup’s combined team of structural engineers, procurement, research and technology experts also developed a strategy for combining low-cement concrete and new Earth Friendly Concrete – an entirely cement-free alternative. Compared to mixes without any cement replacements, this combined construction intervention saved respectively up to 33% and 70% of embodied carbon.
Working with IF_DO, and London-based artist Lakwena, who together envisioned the kaleidoscope-effect and the inscription on the structure ‘Here we come, here we rise and shine’, the substation is widely acknowledged as celebrating the spirit of the community. It brings life and colour to the cityscape through the use of its rotating billboards. With an eye on future circularity, these billboard panels can be swapped out, refurbished and replaced in years to come.
Functionally, the substation is critical to Brent Cross Town achieving net-zero by 2030. It will supply electricity to the entire town, as well as powering the community’s district heating and cooling centre – developed in collaboration with Vattenfall, an energy organisation based in Sweden. Its capacity to provide renewable sources will evolve as climate action and resilience continues to be prioritised within the new community.
Did you know?
For the project, just over 42% of structural steel was recovered from old and unused oil pipelines, which reduced the embodied carbon of the steel frame for the Brent Cross Town substation by over 40%, saving 99.2t of CO₂e.
As an open-air structure, the substation benefits from natural ventilation, meaning operational carbon emissions are reduced by design. By comparison, common practice is to locate substations and any related infrastructure equipment within a building – hidden and requiring mechanical cooling.
This approach and design strategy has enabled the project to be low-carbon from initial use with plans to be entirely decarbonised by 2030.
Greening a disused landscape
The complimentary relationship between nature and circularity is often overlooked, despite the extracting and processing of natural materials driving over 90% of biodiversity loss. When considering our net-zero agenda and circularity for change, it is also imperative that we consider our potential positive or negative impact on biodiversity, prioritising rewilding wherever possible – especially within cities.
In the case of the Brent Cross Town substation, Arup collaborated with landscape architects Gillespies to bring the surrounding ex-industrial area back to life, advising on ecology best practice and sustainability strategy.
A wildflower meadow has been established to provide a biodiverse setting for the substation, enhancing local wildlife corridors. The broader Brent Cross Town project also reflects a strong biodiversity focus, with the regeneration scheme encompassing over 200,000m² of green space, prioritising easy access to nature with parks, nature trails and new cycling routes.
Greater consideration of biodiversity enhancement is needed alongside carbon reduction and circularity to enable a step-change, and for impact to be truly equitable. Arup has recently partnered with C40 Cities (see box-out below) to navigate the restoration of natural habitats for health and wellbeing in urban spaces. These considerations should be undertaken in conjunction with our thinking around material reuse and value retention to truly deliver holistic progress, bringing together multidisciplinary expertise so that projects harness every opportunity possible.
C40 Cities
C40 is a network of around 100 mayors from around the world. The goal is to tackle climate change in these cities, using an inclusive, science-based and collaborative approach.They aim to meet the global target of halving emissions by 2030 and limit global heating to 1.5°C by building healthy, equitable and resilient communities.
Membership is based on meritocracy and not fee-based. The C40 include cities that:
Have adopted a resilient and inclusive climate action plan aligned with the 1.5˚C ambition of the Paris Agreement, and updates it regularly.
Remain on track in 2024 to deliver its climate action plan, contributing to increased resilience, equitable outcomes and halving C40’s overall emissions by 2030.
Use the necessary financial, regulatory and other tools at their disposal to address the climate crisis and mainstream their equitable climate targets into the most impactful city decision-making processes.
Innovate and start taking inclusive and resilient action to address emissions beyond the direct control of the city government, such as associated with goods and services consumed in their city.
Demonstrate global climate leadership and inspire others to act in support of the Paris Agreement.
Arup worked with C40 to create the report, Urban Rewilding: the value and co-benefits of nature in urban spaces. Urban rewilding is defined as 'restoring natural habitats and their processes in urban spaces, working towards a state of human-nature coexistence'.
The report uses case studies around the world – including urban greening in Nigeria to rewilding corridors in Portugal – to highlight how urban rewilding projects are key to fighting biodiversity loss and climate change.
Going further
Collaboration will be at the forefront of any infrastructure innovations of this nature and is essential for circularity to be brought into the mainstream. In the UK, we have a circularity gap of 92.5%, reflective of the current strains and pressures on supply chains across all industries.
Businesses, regardless of sector, are exposed to increasing and inevitable demands for raw materials, meaning value retention must be prioritised alongside circularity as a lever for change. Simply put, one cannot deliver sustainable results optimally without the other – a balance has to be struck.
This requires intricate expertise and nuanced experiences in an industry that is continuously evolving.
