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39%

reduction in embodied carbon in structural projects since 2011

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Envision Sustainability Professionals

Established in 2011, the Embodied Carbon Laboratory, which studies the embodied carbon in our structural engineering projects and formulates strategies for its reduction, was among our first endeavors to introduce sustainable design into structural engineering. The lab’s work continues to improve our understanding of embodied carbon, internally and within the structural engineering field. Why embodied carbon? Building structures incorporate substantial quantities of steel and reinforced concrete. These materials contribute to climate change through their embodied carbon, the carbon dioxide and other greenhouse gases emitted during raw-material extraction, refining, manufacture and transportation. In a typical building, structural materials account for 50 percent of the embodied carbon.

Six years ago, we began measuring the embodied carbon in our structural projects. As an adopter of the Architecture 2030 Challenge, we realized that since our staff is composed primarily of structural engineers, the best way for us to reach its target of carbon-neutral buildings by 2030 was to reduce greenhouse gas emissions associated with structural materials. Since 2012, as a member of the American Institute of Architects 2030 Commitment, we have reported to the institute annually on the quantity of embodied carbon in our structural projects. Our 2017 data reveal that, although the embodied carbon in our projects has fallen by 39 percent since it was first measured seven years ago, reductions in project-related embodied carbon have plateaued. The average embodied carbon in our structural projects hovers at around 30-33 kgCO2 per square foot, where it has remained for the past four years. An early decrease in embodied carbon likely reflected a wider use of cementitious replacements in concrete, but the current trend indicates that reduction technology has not progressed. We continue to drive our own internal efforts to identify areas where further reductions can be made.

Average Embodied Carbon per Square Foot

50

Kg CO2/ft.2

40 30 20 10 0

2011

2012

2013-14

2014-15

The challenges we and benchmarks, a understanding, and driving adoption – a To address these ch active member and of the Carbon Leade industry-academic c the University of W community of AEC and manufacturers w understand and redu in building materials embodied-carbon d projects to the CLF

In 2017, as one of s members, we made the development of 2050 Commitment, will challenge struct meet embodied-car progressively higher “race towards the m We also began build industry association for the first stage of

Average Embodied Carbon by Market Sector

60

Kg CO2/ft.2

Our Services

Innovations in Sustainability: Sustainability in Structural Engineering

2015-16

2016-17

Left: Six years ago, we began measuring the embodied carbon in our structural projects. Right: Here, we compare our numbers to the 2016 Carbon Leadership Forum Embodied Carbon Benchmark Study, which compiled embodied-carbon data from multiple sources.

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Commercial

Education

Thornton Tomasetti 2017 Carbon Leadership Forum Study

Residential

2017 Sustainability Report: Envisioning an Enduring Organization  

We believe that practicing corporate responsibility and sustainability is the right thing to do. Read our 2017 sustainability report to lear...

2017 Sustainability Report: Envisioning an Enduring Organization  

We believe that practicing corporate responsibility and sustainability is the right thing to do. Read our 2017 sustainability report to lear...