Case study 2022: Stephen Elderkin

Director of Environmental Sustainability for National Highways

Stephen Elderkin is Director of Environmental Sustainability for National Highways. He started his Policy Fellowship in 2018 and is now a Continuing Fellow at CSaP. Here Stephen describes a meeting he had with a Cambridge University academic which has led to a potential saving of tens of thousands of tonnes of carbon dioxide each year.

The CSaP Policy Fellowship programme has been a helpful opportunity to get away from the day-to-day of meetings and take a step back.

One of the key deliverables for me, as National Highways’ first Director of Environmental Sustainability is our Net Zero Plan, which includes a commitment to reduce construction and maintenance emissions to net zero by 2040. In 2020 our construction emissions were around 730,000 tonnes of carbon dioxide arising from transport, use of plant machinery and embedded in the materials we use on our construction sites. Concrete is the largest contributor to that construction footprint.

It has always been clear to me that the connection between the deep expertise and the decision-makers to have a real-world impact is so important. My experience has shown that CSaP is a great mechanism for that.

Through CSaP I met Janet Lees (Civil Engineering Professor, University of Cambridge) and she highlighted something very crucial to me. She suggested that if we change our concrete standards and permit the use of a different type of mix (from quality control batching plants known as ‘Gen 3’) that in many cases we could reduce the amount of cement that was required to achieve the design strength by 30%. By reducing the amount of cement in the mix by 30%, this also reduces carbon emissions by around 30%. She highlighted a brilliant example of how we can make quick and tangible progress to help tackle the climate crisis.

The change creates an opportunity for suppliers to use higher quality control and lower cement mixes, which can save tens of thousands of tonnes of carbon dioxide each year- with very low technical risk. I am very grateful to CSaP and to Janet for highlighting this to me. Thanks to her, I was able to speed up the process internally, and we managed to make the required changes within two months. We are now starting to make savings on carbon dioxide. Not only is this a huge symbolic victory, but it has catalysed a whole set of industry conversations about how we can change our standards more quickly.

Over a hundred countries around the world adhere to and adopt our standards. We will now go through a full process to adopt these changes formally into the full Design Manual of Roads and Bridges (DMRB) to start making a global difference, as well as here in the UK.