by Sam Estall, in conversation with David Walker
In the dynamic landscape of construction and sustainability, recognizing and addressing carbon emissions in building materials is a critical step towards a greener future. We sat down with David Walker, the Environment, ESG, and Sustainability lead for the High-Speed Rail 2 (HS2) project, to delve into the nuances of embodied carbon and the transformative measures the industry is taking. Here are the highlights from our conversation.
Factors contributing to embodied carbon
The journey begins with understanding the main contributors to high levels of embodied carbon in building materials and systems. According to Walker, the use of energy-intensive materials, particularly cement and glass, plays a pivotal role. The manufacturing process for these materials is carbon-intensive, creating a substantial environmental footprint. Extractive processes like mineral extraction and long-distance transportation also contribute significantly, relying on fossil fuels with high carbon emissions. Moreover, the relatively short lifespan of buildings and inefficient material retention during demolition pose additional challenges to recycling lost materials.
Reducing embodied carbon throughout the lifecycle
The construction industry is not resting on its laurels. Walker points out ongoing innovations aimed at reducing embodied carbon. Low-carbon concretes and hybrid materials are currently in development, offering promising alternatives with lower carbon footprints. However, he emphasizes the need for a delicate balance, ensuring that these materials prove their longevity and reliability. The industry must navigate the terrain of risk and reward as it ventures into uncharted territories of sustainability.
Tools for measuring and reducing embodied carbon
Tracking and measuring embodied carbon require sophisticated tools, and here, Building Information Modelling (BIM) software takes centre stage. Carbon tracking products and software enable benchmarking comparisons between traditional and innovative materials. As the industry marches towards 2023, low-carbon concrete, utilizing different energy sources in its creation, is poised to revolutionize construction methods and reduce embodied carbon.
Rethinking building components
One commonly overlooked aspect is the default mindset in construction. Walker challenges this mindset by asking a crucial question: does a staircase need to be made of concrete? Sustainable materials can meet fire protection and resilience standards, presenting a wider range of options for designers and engineers. Overcoming ingrained perceptions is key to accelerating the embrace of low-carbon methods and materials.
The cost conundrum
The elephant in the room is the perception that lower-carbon alternatives are expensive and may not perform as well. Walker addresses this concern by highlighting the economic scale. As demand for these materials increases, manufacturing costs will decrease, making sustainable alternatives more economically viable. Case studies and research play a pivotal role in dispelling myths and building confidence in the efficacy of low-carbon materials.
The future of embodied carbon reduction
Looking ahead, Walker envisions regulatory measures as a crucial governmental focus. Building regulations that mandate superior carbon performance are essential. It's imperative to steer clear of greenwashing and carbon offsetting schemes, relying instead on tangible projects and case studies to showcase the potential of innovative materials. Walker emphasizes that true alternatives are not only available but necessary to drive meaningful change in reducing embodied carbon.
As we navigate the path to a sustainable future, the construction industry stands at a crossroads, armed with innovations and a growing commitment to environmental responsibility. The journey towards reducing embodied carbon is not just a responsibility but an opportunity to redefine the future of construction. With leaders like David Walker paving the way, the industry is on track to build a greener tomorrow. For the full interview with David Walker, visit the Resibuild website here.