The net-zero benefits of the principles are accepted, but a bank of strong case studies and knowledge sharing is needed to make it a practical reality.
The UK government made a commitment to achieving significant carbon reductions by 2037, but is expected to fail if the current system is not challenged.
According to the Climate Change Committee, the construction and building sector is currently failing to upgrade building stock, while it has already been acknowledged that energy efficiency measures will not be enough to meet net zero targets.
The greatest opportunity for reducing carbon in the built environment is not to build anything new at all. And where new or upgraded infrastructure is necessary, significant carbon reductions can be made by minimising the use of virgin materials, designing for recovery and using low-carbon materials.
Why we need circular economy principles in the built environment
Circular economy principles provide this holistic approach, as one of its core goals is keeping assets, components, products and materials at their highest value for as long as possible. The underlying carbon reduction assumption is that using less material results in a lower carbon impact compared to the use of virgin materials.
Circular economy targets, including amount of waste generated and treated, percentage of recycled content used versus virgin material and percentage of biological material used, drive carbon emissions reduction and support net zero ambitions.
This is being endorsed by the standard for managing infrastructure carbon PAS 2080, which presents a hierarchy of options for carbon reduction from building nothing to building less, followed by building smart and, finally, by building efficiently.
Maintaining and refurbishing rather than dismantling and building new allow embedded emissions – those that are produced by construction processes and building material production - to stay captured in the built environment. This means that setting targets on maintenance and refurbishing, rather than on new builds, is an effective way to reduce carbon.
For new projects, the Ellen MacArthur Foundation found that 80% of environmental impacts are determined at the design stage. Waste across the lifecycle of projects should therefore be seen as design flaws and assessed and designed out at early stages.
Using recycled material and planning for its recovery are other efficient ways to reduce carbon emissions, providing performance indicators that are easy to measure and track.
At the decommissioning stage, biomaterial used can be safely and effectively returned to the soil and other ecosystems, enhancing natural resources and supporting ecosystems, and reusable materials put to reuse.
Recycling building material is another option to reduce carbon emissions from energy and material waste, though reuse is preferred as recycling processes generate emissions.
Recovery targets can support the built environment to reduce carbon emissions by pushing for better project design, material quality and maintenance efforts.
Key issues and challenges
Studies from the Ellen MacArthur Foundation found that knowledge about circular economy principles is missing in the industry and that it should be circulated more, with a focus on the practical steps necessary to implement actions.
The circular economy model needs investors to support it. However, a number of reasons make them cautious.
Currently, circular economy projects in the built environment are mainly publicly funded or developed internally. A lack of clarity about the financial outcomes of the projects leads to investors doubting business cases.
Also, the construction industry hasn’t seen any disruptive innovation in decades, and not having collaboration and leadership - made difficult by the fragmented industry - in the circular economy model reinforces their caution.
Having a leading player in the industry setting circular economy targets and strategies seems to be the key to implementing circular economy principles and accelerating the path to net zero in the built environment.
How the South West is adapting
The consequences of climate change can already be seen in the South West of England, and it’s predicted to be significantly affected by climate change in the near future, with increased extreme weather events, such as flood, drought and heatwaves.
These events directly affect the built environment, and its resilience will be tested more and more, but by embedding circular economy principles, the sector could support climate change mitigation.
Some councils in the region, including Devon and Cornwall, are already embedding circular economy principles to achieve net zero.
In 2019, Devon County Council launched its “Devon Carbon Plan”, a roadmap to achieve net zero by 2050. This plan includes built environment ambitions and targets in terms of retrofitting and net zero new build, which align with circular economy principles.
In the same year, Cornwall Council issued its “Climate Change Action Plan”, with one of the three carbon neutral priority projects being in the built environment.
Cornwall’s roadmap includes a specific section on circular economy transition for the commercial and industrial sector, which encompasses the built environment, with the ambition that circular economy principles will become mainstream by 2030.
Meanwhile, Ricardo Energy & Environment’s Head of Sustainability Hannah Lawrie recently joined the South West Infrastructure Partnership’s (SWIP) steering group to provide specialist circular economy representation.
She has more than 20 years’ consultancy experience across waste and resource management, circular economy and sustainability, and is the waste and circular economy specialist on the Task Force set up to produce the Devon Carbon Plan.
While local policymakers understand the urgency and benefits of implementing circular economy principles in the built environment, their ambitions still need to be translated into practical actions.
The need for circular economy targets to achieve net zero carbon emissions by 2050 is understood and accepted by all those involved in the built environment, but it cannot be implemented without collaboration and leadership.
Policymakers, investors, developers and operators need to work together to develop a circular built environment hub that will drive knowledge sharing and leadership.