Making low-carbon material choices

摘要

In August 2020, the Institution released a guide, How to calculate embodied carbon', outlining a consistent approach for structural engineers to use in tracking embodied carbon on their projects. The guide enables engineers to calculate both the upfront carbon (modules A1-A5), whole-life carbon (modules A-C) and potential future benefits (module D). Embodied carbon is a fantastic metric to compare efficiency across different material types, and while it is only part of the wider sustainability picture, it is a current topic of choice due to the need to dramatically decrease carbon emissions around the world2. In this article, we look at the four most-used materials in structural engineering -masonry, reinforced concrete, steel and timber - and discuss how to make low-carbon choices for each. All four materials, when detailed correctly, can last far longer than the typical design life of a building, and each has sustainability advantages and disadvantages. Historically, there has been much debate as to which material is 'lowest carbon' or 'most sustainable', but of course the answer is not as simple as that. As with all things in engineering, it depends on the situation - with different materials most suitable for different scenarios.