This is one of five major green building trends we’ve identified for 2019. To explore more of them, see our Five green building trends for 2019 cover story.
The construction industry finally has a plan of attack along its most formidable remaining front in the war against carbon.
So far, architects, engineers and builders have addressed only half the problem. To be sure, they’ve made a lot of progress. New and renovated buildings operate more efficiently than ever before. Energy-use intensity has dropped with each advance in lighting, mechanical systems, insulation, codes and design. Those improvements, alongside leaps forward for solar energy, now make net zero buildings truly viable. If the construction of highly efficient buildings isn’t yet widespread enough, at least it’s headed in the right direction.
It’s all good — right? No. Not really.
“We’ve been focusing hard on the operations side,” says Skanska USA Sustainability Director Stacy Smedley. “[But] we now know that if you look at a building’s lifespan, between now and 2050, half of the carbon will come from operations and half will come from carbon embedded in the materials used in construction.”
In other words, carbon emitted in the process of manufacturing materials, transporting them to the job site and constructing a typical building is equal to the amount that the building will emit during three decades of operations. And it stands to reason that the more efficient building operations get, the larger the share of the problem owned by materials and construction.
Wrapping one’s arms around the issue of embedded carbon has seemed an insurmountable task — replete with starts and stops, transparency issues and a lack of standards.
Smedley is part of a team working with the University of Washington Carbon Leadership Forum to develop a standardized system to track carbon embedded in construction materials. They began by collecting data on more than 1,000 buildings, categorizing buildings by type, and digging into the carbon emissions embedded in components of those structures.
One highly efficient Seattle mid-rise demonstrated just how big an elephant in the room materials have become in any discussion of buildings and carbon. The benchmarking exercise found that “it will take 255 years of building operation to equal the amount of embodied carbon produced during manufacturing and construction.”
This isn’t an entirely novel endeavor. Athena Impact Estimator, Tally and One Click LCA are among the tools competing to help project teams measure manage embodied carbon. While LEED offers a credit for lifecycle carbon assessment and the Living Building Challenge sets an “imperative” for embodied carbon, the organizations behind those two certification platforms are developing separate standards for a more systematic “Zero Carbon” certification.
As with the evaluation of toxicity in materials, however, the effort to assess carbon impacts has been stymied by a lack of transparent, systematically collected data.
“It’s at the level of all manufacturers that this information needs to be shared, and there has to be a common understanding of it,” Smedley says. “Everyone needs to come up with their emission data the same way.”
The fruit of all this labor is called the Embodied Carbon in Construction Calculator, or EC3. Although it’s meant to complement existing lifecycle assessment tools, EC3 is an embodied carbon application in its own right. It includes an open-source database on embodied carbon for materials and products, which can be communicated to end users in the form of Environmental Product Declarations.
Microsoft has joined Skanska as a key partner on EC3. Skanska is the general contractor on the software giant’s Redmond, Wash., corporate campus, and the two companies are piloting EC3 on that project.
EC3 is scheduled to become available to the public later this year.
PHOTO AT TOP: A massive renovation of Microsoft’s corporate campus in Redmond, Wash., is serving as the pilot project for EC3. Photo courtesy Microsoft.
The Kendeda Living Building Chronicle reports on regenerative design and construction, which a special focus on the Kendeda Building for Innovative Design and Construction. To explore more of our Five Green Building Trends for 2019, click here.