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Structural engineers and the circular economy

Circular Economy By Neil Dely, Partner, Structural Engineering – 11 November 2021

Metal piping in a circular formation


Neil Dely wearing a light blue shirt and striped tie in the Edinburgh office

Neil Dely

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The Space for Architecture Carbon and Environment (SpACE) is a pop-up venue in the former fire station in Lauriston Place in Edinburgh. It is hosting several exhibitions and seminars during and beyond the period of COP26 to increase awareness and share knowledge.

I attended a seminar called “Can the Circular Economy Save the World” and the ensuing discussions challenged me as a structural engineer to think about the pivotal role that structural engineers could play in helping to develop the circular economy.

The Ellen McArthur Foundation have said, “ A circular economy is restorative and regenerative by design, and which aims to keep products, components and materials at their highest utility and value at all times”. (The circular economy at COP26, 2021)

If one is to follow these principles, it means designing to ensure that buildings are adaptable so that they can be reused and refurbished. It also means designing components and materials to be recoverable and reusable.

Noting that in Scotland where construction activities account for 50% of all our waste, taking this approach should help stem the flow of materials to landfills where all their value is lost.

In thinking about what was discussed with my structural engineering hat on, I reminded myself that we are used to looking at existing buildings and carrying out building appraisals to understand their condition. Here are some of the things that are already in our armoury:

  • we know that in general, structural materials will last long beyond the design life ascribed to a building if they are kept in good condition.
  • we are used to carrying out a desk-study investigation to understand the history of the building to understand the original design principles and parameters.
  • we are used to looking at testing to try and understand the properties of materials and by extension how structures will behave.

So, I would say that we understand the reuse and refurbishment piece, although we could always do more and learn how to challenge our clients more effectively so that they follow this option. However, in contrast, we have not really got our heads around the re-use of individual components.

In days to come, one imagines that all components of a building will have a QR code that travels with them as they move from new locations within a building and for reuse in different buildings … but we are not there yet.

The fairly recent protocol around the reuse of structural steel gives a helpful framework for designers, but what about other materials? (The Steel Construction Institute, 2019)

In my opinion, this whole issue is a bit of a “chicken and egg” situation where there needs to be a demand for these components and means of supplying them. One cannot exist without the other and to break into that loop, it will be necessary to increase awareness and develop guidance to move the whole thing forward.

There may be legal and commercial challenges, especially of foundations in this regard. But should we allow these challenges to prevent us from trying to push forward? As with so many things, early advocacy and consultation are critical. Most challenges can be met, and problems can be solved if there is a will and if they are discussed early on.

So, coming back to structural engineers. With our knowledge of the behaviour of materials and the existing knowledge of appraisal, we should be playing a pivotal role in this - clients need sound technical advice about what can be achieved.

But clearly, we are not alone in this and the work that EGG Lighting (one of the contributors to the seminar) are doing shows how these principles can apply not only to components of the fabric of a building, but also to the items of electrical and mechanical equipment. Are we moving towards a time when air handling units will be remanufactured rather than being discarded?

This does not happen at present, but I know that colleagues have started the conversations with manufacturers to see how we can influence a move in this direction.

Cundall is on a journey to achieve zero carbon design on 100% of our projects everywhere in the world by 2030. This is a global initiative that engages everyone in Cundall - every office, every discipline, and at every level – to deliver zero-carbon solutions. We will develop training programs, tools, and guidance for our teams, and will share our knowledge with the industry.

We recognise that not every project can achieve zero-carbon today and we will work with our clients and industry to make this transition as fast as possible. The principles of the circular economy and getting our head around the re-use of components will certainly be a part of this exciting and urgently necessary journey.

References 2021. The circular economy at COP26. [online] Available at: <https://ellenmacarthurfoundati...> [Accessed 2 November 2021].

The Steel Construction Institute. 2019. Structural Steel Reuse: assessment, testing, and design principles. The Steel Construction Institute, p.427.