Author: Oliver Hall, Make Architects
One of the most-quoted statistics on the impact of embodied carbon in
the built environment is that 80
percent of the buildings we’ll need by 2050 already exist. This provides a
clear rationale for the reuse and retrofit of existing buildings; however, as the
redevelopment of city office buildings continues at a rapid pace, there are
many examples where keeping existing buildings isn’t seen as a viable option –
whether that’s for financial, structural or various other reasons. This
conflict leads to fierce debate and friction between carbon and commercial aspirations
and priorities.
The principles
of circularity may provide a resolution to this debate. When viewed from a
circular mindset, existing buildings have much to offer, and by designing
adaptable, demountable structures, we have an opportunity to sustainably extend
the lifespan of buildings and their materials.
To further
understand and explore these opportunities, BCO Nextgen brought together a panel of industry experts working at the
forefront of circularity. These included Rachel Hoolahan (Sustainability
Coordinator at Orms), Steve Gilchrist
(Project Director at Grosvenor), Andrea Charlson (Commercial Manager and Built Environment Lead
at ReLondon), and Laura Batty (Structural
Engineer and Associate at Heyne
Tillett Steel).
Circular
design at all scales
Rachel Hoolahan set the challenge at Orms to aim for at
least one deep sustainability assignment on each project. This design-research
mentality is leading to innovation that unlocks circular economy opportunities.
During the panel discussions, she raised the challenges and questions brought to
light during the redevelopment of 160 Old Street, a
former Royal Mail sorting office.
The project achieved a 70 percent uplift in net internal
area through a reconfiguration and extension, while retaining 76 percent of the
existing structure, saving nearly 3,000 tons of CO2 emissions. The key challenge, however,
was ensuring the additional floorplates were flexible and of a high-quality, as
expected in a new building. Although the retention and extension of the
existing structure had the biggest carbon savings, it was in the selection,
specification and design of new elements that needed the most challenging. Hoolahan
gave the example of the ceramic sinks in the washrooms, which could be “easily
uninstalled, disassembled and reused in the future, [while opening] up the
opportunity to source reused sinks as the initial specification.”
While this is just one example of a ‘deep assignment’, by
implementing this circular mindset both at a large and small scale, the
materials and the building are ensured for long-term, flexible and sustainable
use.
Developers driving innovation
Grosvenor has been exploring circularity innovations across
several projects, both in terms of practical applications and the long-term
implications of them. They see materials reuse as an opportunity to balance
their materials across a range of sites. But as project director Steve
Gilchrist explained, circularity can be a wide-ranging topic, so you need to be
focused to create any meaningful change.
He explained that during a recent project, in collaboration
with Orms, Grosvenor paused the design to slow down and focus on the long-term
impact of the building. Steve said, “We want [the design team] to learn
about the building now, [and] think about how things could be done in the
future,” before rushing into the design. This thinking, combined with
Grosvenor’s ambition to explore the full process of implementing circularity,
meant the design team could engage with detailed building surveys and thoroughly
understand the materials within the building, and whether they could be reused.
The team also worked with lawyers on warranties, to ensure these ideas could be
implemented in a commercially sustainable way.
In demonstrating to supply chains that reusing materials
from existing building stock can be viable, Grosvenor are paving the way for
more detailed circular material models in future.
Creating a model for circularity
While the private sector is making tremendous progress, the
public sector is critical to the successful adoption of circular economy strategies
across the industry. ReLondon, a partnership between the Mayor of London and
the London boroughs, is on a mission to revolutionise London’s relationship
with products and waste. As Andrea Charlson put it, ReLondon are “helping
London waste less, reuse, recycle, repair and share more.”
One of ReLondon’s focus areas is the inclusion of circularity
in The
London Plan. The policy around reducing waste and supporting a
circular economy has four key elements; a requirement to collaborate, promote a
more circular economy, produce innovation, and adhere to targets around waste
diversion from landfill and reuse. However, the most significant element for
most large developments is the requirement for referrable schemes to submit a circular
economy statement as part of the planning process. Two of the most interesting components
of embedding circularity in the planning process is the need for a pre-demolition
audit – if the site’s being demolished or redevelopment – and the post-construction
requirements that show how a building can be adapted and reused in future. Where
this is implemented, it is expected that we’ll see a real-world reduction in the
use of virgin materials across the whole life of a project, leading to a
reduced carbon budget.
ReLondon is part of a consortium of 31 organisations across
4 cities (London, Copenhagen, Hamburg and the Helsinki region) who are working
together on the Horizon 2020-funded ‘Circular
Construction in Regenerative Cities’ (CIRCuIT) project.
Through the project, they are aiming to reduce the yearly consumption of virgin
raw materials by 20% in new construction, and show cost savings of 15% –
something that can only be achieved through collaboration. ReLondon are also trying to improve the
quantity of data available, and the accessibility of existing data, while
providing tools to access it – all of which will help ReLondon, and fellow
organisations, achieve this collective goal of reducing waste and carbon.
By pushing for policy change in the public sector, ReLondon
are steering the local industry, and indeed a global city, in the direction of
circularity.
Engrained disassembly
While the opportunity and scalability of circularity offers
the potential to revolutionise the construction industry and reduce our impact
on finite resources, there are also easy wins that all projects can, and must,
start actioning. Not every project will have a reusable structure, and not
every project team has access to a materials bank, but through early design
decisions, we can make new buildings easier to adapt, reuse and disassemble in
the future.
Laura Batty runs the internal research and development
department at Heyne Tillett Steel, where they’ve been exploring the principles
of circular design and disassembly on various projects, including their new
offices at 16
Chart Street. She says the opportunity to extend the lifespan
of the things we use is important, and by creating structures that are “designed
to be disassembled and reused at a higher possible value, [we are] eliminating
waste and pollution, avoiding things being designed to be thrown away, and
designing instead to facilitate reappropriation and recycling.” Designing structures
that can be disassembled using bolted connections and exposed steelwork, for
example, makes the process of disassembly more achievable when the building’s
functional life is over.
By factoring the end of a building’s life into its design,
we can redefine the life cycles of buildings and establish a framework for a
circular industry.
Conclusion
It’s clear from the panellists that circularity cannot be
achieved in isolation – it needs to be a collaborative process, between
internal teams, developers and designers, and the public and private sectors. Circularity
looks set to revolutionise the workplace life cycle and reduce the sector’s
impact on the environment, but only if everyone involved is willing to move
beyond the standard models of design, procurement and occupation, and shift
towards closing the loop instead.
We wish to thank our panellists for their unique, expert
perspectives on the challenges and opportunities of circularity in practice. To
listen to the full discussion, click the link here.
