Incremental structural design decisions can save BIG on carbon.

Increasingly frequent extreme weather events around the world continue to underline the importance of changing the way our behaviour impacts our environment. As structural engineers and designers, we can play a crucial role in lowering carbon emissions produced by buildings. Many of our decisions have significant carbon consequences, and it’s important to review the decisions we make on a project-by-project basis to determine if there are efficient alternatives.

In our industry, the narrative surrounding carbon reductions often associates these reductions with higher costs, pointing to the need for high-performance and expensive materials. However, there are strategic design decisions and efficient construction practices that have minimal or even a net positive financial impact that can lead to substantial carbon reductions. Big changes aren’t always necessary to make a big impact — small wins can make a difference.

At ASPECT, sustainability is a core part of our business and, over the years, we have created tools, such as our Embodied Carbon Calculator, to help us make efficient decisions. As we learn more, we continue seeking ways to reduce carbon, and our latest initiative, “Small Wins, Big Impact”, aims to encourage our engineers to make smart and efficient design decisions at all stages in the design process, rather than solely focus on big, sweeping decisions made at project kick-off meetings.

Creating the initiative…

ASPECT’s goal is to foster a company culture that considers carbon as a driver on all projects. By tracking embodied carbon in our structural systems, we can identify trends and establish achievable reduction goals. Paying attention now will provide lessons for future projects.

To foster this approach, our new internal initiative asks our engineers to shift their approach: think Small in order to achieve Big. Often, the impact of our role can feel like “all or nothing” – if we aren’t making the big moves to reduce carbon emissions, are we really doing anything at all? Through this new initiative, we strive to highlight that, in fact, anything that is within their control (which, as structural engineers, is not insignificant) will, indeed, have some measurable impact.

For example, collaborating with the architect and acoustic consultant to eliminate concrete toppings on CLT floor panels, can result in 100 tonnes of carbon saved for a 8000 square metre floor area. That’s equivalent to more than six times the annual carbon footprint of just one of our ASPECT engineers!

Through this initiative, on any given project ASPECT team members are encouraged to:

1. Identify opportunities to save on embodied carbon emissions. Specifically, review project details and determine if there are any ways in which carbon can be saved. For example, increasing reinforcement rate and decreasing slab depth can save 50-100 kgCO2e /m2 on a concrete building, or exploring alternatives like ribbed or waffle slabs early-on in design can reduce the embodied emissions of a floor slab by up to thirty-five per cent!
2. Calculate the potential savings through the ASPECT Embodied Carbon Calculator. This tool can be used to review the embodied carbon in various materials, compare options, and determine what emissions are worth pursuing for each project.
3. Share the idea! Knowledge is power, and all of our team members use this information to have a conversation with the project team.

Through this initiative, our engineers have been finding small ways to save on every project and are rewarded for their innovation and successes are shared with the rest of the ASPECT team. We even implemented a small prize once per quarter for the engineer with the most significant carbon savings through their submissions, and at the end of the year we will celebrate an overall winner.

This initiative demonstrates that small design decisions on any project, not just high-profile developments, can add up, and result in a significant positive impact on embodied carbon.

Looking ahead at the future of embodied carbon in the industry.

ASPECT was an early signatory for the Structural Engineer 2050 (SE2050) challenge, which commits to achieving net zero embodied carbon structural systems by 2050. We are also committed to supporting the Architecture 2030 reduction targets of up to 65% reduction in total global emissions by 2030 — a step that will support reaching our goals for 2050.

These commitments— though they seem large — start small, with changes happening inside organizations like ASPECT. “We need to prioritize embodied carbon reduction on our projects today to meet our goals for 2030 and 2050,” says Caroline Butchart, ASPECT Sustainability Lead, who joined our firm in November 2023. What’s the best way to prioritize these reductions? If you talk to industry leaders like Caroline, it’s through smart changes that make reductions without adding significant project expense.

Structural engineers play a key role in lowering embodied carbon when designing developments. While the overall task may seem large, every small decision made on a project can make a difference. We look forward to sharing what our engineers achieve through this initiative (and beyond)!