12 July 2024
Why we need to consider the whole life carbon impacts of materials including timber and concrete.
By Chris Leese, chair, UK Concrete
Too many material decisions in our built environment are being made based on perceived views rather than data.
Determining the whole lifecycle impact of the materials that are the very fabric of our society calls for a more honest, informed and holistic dialogue about where they are sourced, transported and manufactured.
This approach must also assess their in-use performance and their ability to form part of longer life durable and resilient buildings and infrastructure as part of a circular economy.
Across UK construction, there is still not enough of a forensic focus on where all materials come from and a lack of decision-making based on whole life carbon.
Greater levels of transparency and data about materials and supply chains are required to help clients, contractors and material providers to start to focus on their scope 3 emissions – those that an organisation is indirectly responsible for, up and down its value chain.
Having understood scope 1 and 2 emissions, many clients and contractors are grappling with the scope 3 challenge and how to develop comprehensive strategies. Looking at carbon across materials and responsible sourcing practices will be essential.
Timber is one such material that benefits from positive perceptions about its environmental performance and versatility. But there are facts that need to be taken into account about the whole life carbon impact of the material and sourcing.
The International Institute for Sustainable Development has challenged timber lifecycle carbon assessment (LCA) studies which assume that all harvested carbon is sustainably replaced by new forest growth in the future. The operational reality is that replacement rates do not achieve carbon neutrality.
Research by the World Resource Institute has also reported that only 20% to 25% of a harvested tree typically makes it into the timber replacing concrete and steel, bringing into question its carbon sequestration benefits. Most of a tree that gets harvested for mass timber therefore ends up as waste or a byproduct, releasing much of the carbon it once stored.
The Institute additionally found that the UK imports 80% of its timber, bringing significant impacts from logging, transport, and processing that need to be fully understood. The use of timber is also contributing to deforestation and habitat destruction, which is increasing at an alarming rate – collectively, more than 16 million acres of forest were lost in 2022.
To make sure that carbon accounting is not misleading, materials industries need clear measurement and reporting, and a focus on delivering the most sustainable outcomes. More understanding is needed to inform and create clear roadmaps for industries such as timber and their contribution to a net zero society.
The UK concrete sector is decarbonising at strong pace but we know that we need to continue this momentum and provide clients and contractors with data to help them make informed decisions.
Not only does the UK concrete industry have an established roadmap to net zero by 2050, but our industry provides a homegrown material that is regulated and transparent, with impacts measured from production through to use. Around 93% of UK concrete is produced here in the UK with the industry prioritising ethical manufacturing. Concrete is 100% recyclable and a key part of a circular economy by maximising the time that resources are in use to extract their full value.
Ongoing advancements in the sector to reduce carbon and meet the ambitious targets set out in our roadmap include innovation for lower carbon concrete mixes, carbon capture and storage (CCUS), fuel-switching, recycling, and reuse.
Making informed decisions based on accurate data is crucial for long-term sustainability and reducing the carbon impact of our built environment. Let’s work with data-led facts and not perceived views.
Ends