Why is this so important?
It is now clearly understood around the world that global warming can no longer be dismissed as mere speculation and that carbon emissions are largely responsible for this alarming phenomenon.
In the face of the climate emergency the only solution that makes any sense to me is that everyone needs to do their bit, big or small, to wean ourselves off our reliance on fossil fuels. Fundamentally we need to consume less and be more aware of our own consumption and the impact that it has on the planet. If everyone can be slowly nudged in the right direction and there is a constant shift to more sustainable habits, then we can make a big difference. Everyone needs to play their part.
How can the construction industry help play their part?
Currently responsible for between 35 to 40% of global energy related C02 emissions, the building and construction industry has to make an intelligent effort to cut down carbon emissions from the entire building life cycle. Making just a 5% saving in material/carbon efficiency on all projects for a year would save 50,000kgCO2.Whilst we cannot deny that our industry contributes hugely to global warming, the positive side of that is we have vast potential to make changes and create a positive difference in battling climate change. This can be empowering, and it drives me to help bring about change in an industry that desperately needs it.
Whilst the industry is well versed in improving thermal and energy efficiencies of buildings in use (Operational Carbon) it has been slow to understand and reduce the energy used to mine, process, transport and construct materials in buildings (Embodied Carbon). Embodied carbon currently accounts for over half of a building’s carbon emissions and a significant proportion of that lies in the structure itself.
As structural engineers are responsible for a significant proportion of carbon emissions, they should be shifting their focus from structural calculations at the back end of projects, towards consulting at the front end on materially efficient concepts. This should prioritise retrofit, efficient concepts and material utilisation, following the net zero design hierarchy. . At this point it is far easier to make carbon savings with small but targeted and effective changes to the architecture. If we truly focus on reducing embodied carbon in our buildings today, this can make an immediate and huge impact, and help in our effort to meet Net Zero targets.
What can we do now?
At Harley Haddow, we are completing embodied carbon calculations on our projects as the norm in order to upskill our engineers and encourage them to think about this issue in all we do. Whilst this approach seems to be commonplace in London firms, it is something that has taken longer to kick in in Scotland and that really needs to change.
This approach allows us to analyse this data to provide standard rules of thumb and advice that can be applied to all projects on ways of reducing it. This enables us to feed into the design process at the point where decisions are made, rather than at the end of RIBA stages when it is often too late to make changes. A key part to this is literacy and education in sustainability in general and a desire to collaborate and compromise to achieve the right result. This is the culture that needs to be fostered within the industry.
In order to continue to play our part, the whole industry needs to continue to capture, process and share data, to drive better decision making, and address the following.
We need to be completing carbon assessments on our projects and interpreting the data to help develop better, more efficient designs and to make us all more carbon literate.
We know that open spaces with longer spans leads to a vast increase in structural material required, but this needs to be quantified in design meetings and alternatives offered. Structural engineers need to be involved in projects right from the early concept stages to help challenge the project brief and help promote structural efficiency in the design. We need to stop demolishing existing buildings and start carrying out more detailed assessments on how to refurbish and reuse these assets, rather than taking the easy option of building new. The IStructE circular economy and reuse guide is a great resource in relation to this.
But if we are being brutally honest with ourselves, it is hard to make industry-wide, selfless decisions to mitigate climate change, and to use less energy for the greater good. If we are to do more than just nudge things in the right direction, we need legislation to be brought in to mandate change. The industry needs Part Z regulations or similar – and I think we are ready to embrace them.
Part Z is an industry proposal to make alterations to the current UK Building Regulations to mandate whole life carbon calculations on all projects before utilising this data to set robust limits on carbon intensity in buildings. The Carbon Emissions (Buildings) Bill was introduced to parliament in February 2022 which mirrored the Part Z proposals; however, this was rejected in November 2022. Whilst this appears to be a huge setback the government is considering tweaking the bill to shift the focus from building regulations into planning policy instead. I hope the bill will be reintroduced in time due to its general support across Westminster and the industry.
Send us your feedback for 'How to calculate embodied carbon (Third edition)'
The Institution is planning to start working on an update to its essential guide How to calculate embodied carbon in 2024, in response to developing industry guidance, knowledge, data, and standards. We are asking users to provide feedback as to how you use the current guide in your work, and for ideas as to ways the guide could be improved. All questions are optional so please just provide feedback where you really want to see change happen.
About the author
Ewan Duffin, principal structural engineer at Harley Haddow, has extensive experience in refurbishment and reuse of historic and listed buildings such as the Scheduled Ancient Monument - Kensington Palace and the Grade I listed Architectural Association.
Whilst working with existing buildings, Ewan specialises in Mass Timber construction and sustainability. To add to this specialty, he is pioneering the consultancy’s work on Embodied Carbon and works closely with the Building Performance and Sustainability team.