Sources: Thornton Tomasetti, New York; CP staff
A global engineer’s seven-year survey of 600-plus buildings assesses materials, structural components and facility types with the highest embodied carbon, and cites a market-driven trend toward increased use of supplementary cementitious materials and recycled steel as the largest driver of a reduction in that metric.
The Thornton Tomasetti survey also finds that concrete structures show less embodied carbon levels than steel alternates; floor slabs represent the highest proportion of embodied carbon in most building types; prestressed concrete hollow core plank or voided concrete slabs may be considered to reduce embodied carbon levels; and, LEED certified buildings show slightly lower embodied carbon levels than non-LEED buildings. Concurrent with the results, the engineer announced the scheduled December release of Beacon, a free embodied carbon measurement and optimization tool programmed for use in the Revit 3D building design environment.
“Structural engineers have the opportunity to be leaders in sustainable design because structural materials are the largest contributors to embodied carbon in new construction,” says Thornton Tomasetti Corporate Responsibility Officer Amy Seif Hattan. “We are sharing the first results of our ongoing study in the hope that it will serve to educate our peers and encourage them to contribute data so we can expand our research and support the development of more sustainable and better performing structures.
“Thornton Tomasetti was an early leader in efforts to engineer low embodied carbon structures as the first structural engineering firm to join the American Institute of Architects 2030 Commitment toward developing carbon neutral buildings in 2011. As a co-founder of the Structural Engineers 2050 Challenge and an active participant in the Carbon Leadership Forum, we are dedicated to growing the body of knowledge and data on embodied carbon in new construction and setting reduction goals that will support the move toward zero carbon buildings.”
For more than a decade, she adds, the industry has targeted emissions reduction efforts on buildings’ operating energy, compelling mechanical engineers and architects to specify materials, designs and equipment to increase efficiency. A new focus on reducing structural materials’ carbon footprint positions engineers to contribute via specifications for structures and foundations or substructures, which account for 55 percent of a typical building’s embodied carbon.