Until now, a building’s carbon footprint has been measured solely by the greenhouse gases (GHG) it emits once construction is complete and it is being used as intended. Webcor, one of California’s largest general and specialty contractors, is championing — and will start systematically employing — a revolutionary new open-access tool that allows benchmarking, assessment and reductions in embodied carbon of construction materials.
In partnership with the Carbon Leadership Forum (CLF), of which it was a founding partner, Webcor has successfully pilot-tested the new Embodied Carbon in Construction Calculator (“EC3”) tool, beta-launched today in Atlanta at the Greenbuild International Conference and Expo. By utilizing the EC3 tool on some of Webcor’s projects currently in construction, Webcor has been able to observe an opportunity to reduce over 30% of embodied carbon against baseline values. This striking opportunity stems from the EC3 tool’s ability to assess the embodied carbon in the materials Webcor procures, allowing the company to evaluate subcontractors’ pricing measured against environmental impact, as well as work with design-build partners to better compare structural design alternatives. This will result in better-informed buying decisions.
“The building industry can make enormous new carbon-reduction impacts, as construction is one of the largest GHG emitters,” said Jenelle Shapiro, Webcor’s sustainability director. “Because Webcor has long been committed to sustainable building practices, we were eager to test and provide feedback on the performance of this tool. When our experience proved its incredible value, we realized that if the construction industry widely adopts this tool, we can take a big bite out of global carbon emissions.”
According to CLF, the building and construction industry is responsible for nearly 40% of GHG emissions worldwide, and 11% of this percentage involves building materials manufacturing. Architecture 2030 estimates that construction demand will equate to “building an entire New York City every month” for the next four decades. It further projects that half of all new construction emissions will come from embodied carbon, which includes emissions from the extraction, transportation, and manufacturing of building materials. All things considered, Webcor knew it had to do something substantial to reduce embodied carbon in construction.
Webcor utilized the EC3 tool to evaluate seven projects with a total gross floor area of nine million square feet. Potential savings from all projects could amount to 138 million kgCO2e, which is a reduction of 36% over the baseline conservative projections and equivalent to removing 29,000 passenger cars from roads for a year. One particular project evaluated in the tool had an achievable reduction of over 50%.
Webcor also used the EC3 tool to compare the carbon intensities of multiple project designs for a proposed commercial office development. The tool helped identify one project design as having an embodied carbon intensity 5% lower than the alternate design.
Materials with the greatest impact on a building’s carbon footprint include concrete, structural steel, steel rebar, and drywall. Choosing suppliers with lower emission amounts, as well as those closer to the project site, can help reduce the embodied carbon associated with these materials.
Even prior to piloting the EC3 tool, Webcor has been conceiving ways to reduce the carbon intensities of its self-perform materials. Its specialty contracting division, Webcor Concrete, prioritizes efficient, low-carbon concrete mixes for its projects. The Webcor Concrete team has provided feedback to CLF on the inclusion of additional concrete performance attributes, which affect the amount of embodied carbon in specific concrete mixes. The goal is to improve the EC3 tool’s ability to distinguish the differing amounts of embodied carbon in various concrete element mix types, such as slabs, shear walls, and foundations.
Shapiro added, “By focusing on environmental transparency for the largest building components we source, we will be able to make better-informed procurement decisions that account for embodied carbon, thus making it possible for our buildings to significantly shrink their carbon footprint.”
Following its testing, reporting, and contributing to improvements in the EC3 tool, Webcor established a company Embodied Carbon Commitment that, beginning in January 2020, will be applied to all future projects. Following are some of Webcor’s embodied carbon commitments:
“As an environmentally committed general contractor, Webcor sees a huge opportunity to reduce the environmental impact of the structures we build, particularly in regard to the footprint of the materials that go into them,” said Jes Pedersen, Webcor CEO. “We believe that setting goals and holding our partners and ourselves accountable to measure the embodied carbon of the materials we source will help us lead the way to a greener construction industry and allow those manufacturers who are falling behind to step up and be a change agent for future generations.”
