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Circular Twin

Net Zero Carbon By Alex Carter, Partner, Structural Engineering – 09 November 2021

Following the research, the team produced this design to show what the building could look like.
CGI of a cut through of a 2 story building with a wooden trellis with trees and plants surrounding


Alex Carter in shirt with office interior background with glass feature

Alex Carter

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Peter Hazzard in beige suit and acoustics feature background

Peter Hazzard

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Net zero carbon design is a very topical at present however, whilst there are beacons of best practice it was still far from being the norm, why? Is it due to project teams approaching delivery as business as usual, is it because clients aren’t able to balance decarbonisation on projects against cost drivers or is it because the construction supply chain lacks maturity on this topic?

Clearly these are all big challenges and to unlock the underlying issues a diverse industry wide team was required. The Circular Twin study was created to do exactly this. The collaboration was led by Morgan Sindall with Scape providing a client perspective, Cundall providing the engineering support and a combined team of HLM and Lungfish exploring the architectural aspects.

To truly benchmark the thoughts of the group against “business as usual”, the team revisited a school project that was designed and delivered by participants over 5 years ago. This existing building and its associated design, construction and operational data provided a powerful datum against which we could measure the differences of applying a new paradigm.

Over the course of many conversation and workshops amongst the team and a wide supply chain. A revised design process was adopted to allow space for decarbonisation to be thoroughly explored.

In summary, this unpicked the early stage activities to define a series of project influences and a Should Costmodel. This was followed immediately by an extensive period of supply chain engagement.

The intensity of this process can best be likened to speed dating with meetings convened with different suppliers for each of the products required in the construction over a short period of time. In pursuit of detail surrounding their current carbon intensity and emergent developments to decarbonise their products this dialogue soon took us several tiers down into the supply chain. Undertaking it over short period of time allowed real time comparisons to be established and fed into the design, although risked “dating” fatigue for those involved.

This dialogue distorted the design flow from the norm but this circular approach during RIBA 1 and during the early stages of RIBA 2 design proved key to unlocking major benefits for the project. The delivery work then continued with supply chain embedded into the team for the reminder of the design.

The process developed during the study is captured below a and shows how the conventional design work stages process could be stretched to accelerate the built environment’s race to net zero.