Joined up carbon counting is the way ahead

Andrea Charlson

Whole life-cycle carbon assessment must become part of the construction design process in a logical, joined-up way to maximise carbon reduction opportunities and get the most value out of the process.

Currently, carbon assessment services are largely separate from the design process. This can present challenges both to clients commissioning assessments and to design teams working on the buildings.

If the carbon evaluation is only carried out after the design is complete, the opportunity to make decisions that could reduce carbon emissions is lost. Even if an external assessor is appointed during the design phase, the disconnect between the design and assessment causes delays and even misinterpretation or an error.

In addition, parties external to the design process may suggest inappropriate strategies. For example, alternatives to using Portland cement in concrete are lower in carbon but they also have slower curing times. So the design team will already have excluded such options where programme speed is the key driver of a project.

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"As the industry reduces operational emissions by creating more efficient buildings, embodied emissions will become a much more significant proportion of the total."

I think that several parties need to address this issue. Designers (including architects and engineers) need to become more informed, get used to having these types of assessments as part of the design process and engage with reduction opportunities.

Clients need to decide on the aims of the carbon assessments they are commissioning. They also need to ensure that these aims are clear to the whole project team and on the agenda during project meetings.

Governments and investors need to consider the whole-life carbon impact of their decisions. And manufacturers need to be prepared to supply environmental impact information when requested.

Crucially, the assessments must consider both operational and embodied carbon. As well as a growing demand from clients, there are other good reasons for counting embodied carbon alongside operational carbon.

First, whereas operational emissions will occur in the future, cradle-to-site emissions are occurring now, and so should be a priority for reduction. What’s more, as the industry reduces operational emissions by creating more efficient buildings, embodied emissions will become a much more significant proportion of the total.

Finally, considering whole-life (embodied and operational) emissions during the design phase enables holistic design decisions to be made. For example, it encourages consideration of the relationship between material choices and operational performance, life-cycle performance (including maintenance and durability) and end-of-life scenarios.

I'm pleased that the UK Government’s Low Carbon Construction Innovation & Growth Team has recommended that the Treasury should require whole-life carbon appraisals in feasibility studies. But more still needs to be done to encourage whole life-cycle assessment as part of the design process and to reduce the emissions associated with the construction industry by 50% by 2025, the joint government and industry vision.

I think Building Regulations need to specify whole life-cycle carbon assessment. Can you see a better way to make this change?

'This article was originally published by Arup and has been reproduced with its permission. To view the original article, click here