Understanding the environmental impacts a product will have through its lifecycle is fast becoming a challenge that companies across all sectors are having to grapple with. In the food sector this is often denoted by the ‘farm to fork’ concept. In construction, understanding and measuring the embodied carbon in the materials used is key to the lifecycle assessment of a building.

Construction and the built environment account for some 42% of the UK’s emissions, the majority (close to 80%) of which come from operational carbon. However, over a fifth of these emissions are from the carbon embodied in the materials used in construction. It is further estimated that as operational emissions decrease, we could be looking at more than 50% of the emissions from the built environment coming from embodied carbon by 2035.

The challenge for companies involved in construction is in tracking the materials used, understanding their potential impacts and using this data to measure the embodied carbon within the building. Only by doing this can they start to understand the whole lifecycle impacts of the building. Similarly, without this whole lifecycle approach, it isn’t possible to achieve net zero. Another challenge, as alluded to above, is that the sands are constantly shifting. As decarbonisation occurs across different operational aspects of construction, such as the electricity used, the proportion of emissions coming from the materials used will rise, making it crucial that key decisions are viewed through the whole lifecycle lens.

Embodied carbon at different stages in the lifecycle

Embodied carbon emissions are generated at different stages within the lifecycle of a building:

• When raw materials are extracted, transported and manufactured
• During the construction process
• In the manufacture of equipment and materials needed for maintenance and refurbishment
• At the end of a building’s life when it is demolished

To that end, measuring and reducing them can also happen at different stages, such as before the building is used, at the design and procurement stages and later, while the building is in use and at the end of its life.

Most of the opportunities for reduction happen at the design and pre-use stage and this useful guide from Arup outlines some of the key steps that can be taken.

The role of EPDs

In a world where the drive to net zero by 2050 is becoming increasingly urgent, embodied carbon and lifecycle assessments will be growing factors in decision making around materials. Indeed, to achieve net-zero carbon construction targets, lifecycle assessments will be crucial, providing significant credits towards BREEAM and LEED certifications and the net-zero clauses we can expect to see in future contracts.

To that end, expect to see a growing use of and demand for environmental product declarations (EPDs) for the materials used within a project. Environmental product declarations (EPDs) are standardised documents about a product’s potential environmental and human health impact. EPDs are produced on the basis of life-cycle analysis calculations.

Depending on the client’s sustainability requirements for a building project, architects may specify materials that are sustainably sourced and lower carbon, but in practice, it’s not always easy to follow through from design to the handover of the building to track the credentials of the materials actually used. It is likely however that the data available in EPDs will become as important a factor as price if contract clauses designed to achieve net zero are rigorously enforced and adhered to.

Building information modelling (BIM) systems are designed to record details of all materials and as EPDs become more widespread, you can expect to see this used by more project teams to capture and track the lifecycle assessment of the building. The library of available EPDs is growing all the time, with larger materials suppliers such as Saint-Gobain and Tobermore amongst others creating and publishing their own EPD information to provide transparency and choice to an increasingly environmentally aware sector.

Whether it’s the upstream emissions from materials used in the construction stage or the downstream emissions from the materials once the building is in use, growing demand for transparency and measurement is pushing the construction sector to get a better handle on embodied carbon. In fact, as this blog was being written, events on the topic were arriving in our inbox courtesy of the Supply Chain Sustainability School.

The challenge of measuring

If the industry-proposed Part Z amendment to building regulations which is currently going through parliament succeeds, it will make it mandatory for whole-life carbon emissions to be assessed and limited. That is something that can only be done if the data, and a means to record it at the crucial stage(s) of a project’s development is available.

The challenges that our client companies face when it comes to tracking and measuring the whole-life carbon impact of a building project have led us to work in collaboration to fast-track the development of embodied carbon calculation tools within SustainIQ. This is a really exciting project and one that will be a game changer for the sector. We are trialling and testing this upgrade currently and hope to release it in early 2023.

In the meantime, wherever you sit in the construction sector value chain, whether you’re a main contractor, sub-contractor, materials supplier or architect, expect client demands for information on embodied carbon and lifecycle assessments of materials used in build projects to grow. What systems and processes do you have in place for tracking materials and embodied carbon? How will you incorporate this into your net-zero efforts and what do you need to learn to get up to speed?

Feel free to reach out to us at SustainIQ for a no-commitment discussion about your needs in this space.

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