Strategies for Lowering Carbon Footprint in the Building & Construction Industry

Hosted in late July 2022 as part of their ongoing aec-tech talk series, aec+tech invited industry leaders specializing in sustainable design and construction, to share their insights on lowering the carbon footprint — embodied and operational. Stacy Smedley from Building Transparency / Skanska, Kathleen Hetrick from Buro Happold, and James Bowles from Freeform / Zero talk in-depth about their work and experience in tackling the issues associated with reducing the large amounts of carbon that buildings put into the atmosphere. To watch and follow this and future aec+tech talks, visit our YouTube channel here.

Stacy Smedley: Building Transparency / Skanska

Stacy has more than 18 years of experience in Architecture and Construction: as the Sustainability Director at Skanska, she leads initiatives and high-level sustainability strategies on project delivery and is a subject-matter expert in carbon emissions associated with buildings. As executive director of Building Transparency, she provides open-access data and tools to address embodied carbon’s role in climate change.

Stacy addresses the conversation from both her positions at Skanska and Building Transparency. She mentions that her work over the past five years has focused on enabling low-carbon procurement and industrial decarbonization of the built environment.

This, Stacy says, involves two components — embodied carbon, including all the emissions that are related to building materials and construction, and operational carbon, the emissions from the energy consumed by buildings during their operation/occupancy.

She explains how buildings account for as much as 40% of all global CO2 emissions — this number could even be more if we include its spillover into the transportation of materials and other industries. She says that most stakeholders in the AEC space over the years have primarily focused on operational energy and its emissions, reflecting a serious need to improve our understanding of embodied carbon.

She talks about forecasts of how much the world is going to build in the next few decades: about 2 trillion square feet of buildings worldwide, which is the equivalent of a New York City every 30 days for the next 30-plus years!

Almost half of all the emissions from a building are from embodied carbon, but little has been done or undertaken to understand it further to reduce it.

Whereas the AEC industry has invested a lot of time and resources in improving the efficiency of our buildings during their occupancy, and in decarbonizing our power grids, all of which address just one end of the carbon spectrum. She references her work at Building Transparency where the life cycle of buildings and materials, and the energy used during each stage are mapped out, to understand which areas/phases of each material’s life are the most carbon-intensive. For example, she points to steel and concrete, for which the emissions are the most during the manufacturing stage: this hints that the processes within production need to be optimized to bring down emissions during this phase.

Stacy explains how public and private sector corporations are making zero-carbon commitments that take into account embodied carbon, and how they are trying to meet them on the public policy side. The United Nations Decarbonization initiative encourages disclosure of carbon emissions of common building materials like cement, steel, and concrete, which countries could sign on to. Further, the 5.5 billion USD from the American Federal Budget for disclosure of building materials’ carbon emissions by manufacturers, Stacey thinks, would incentivize low-carbon procurement by architects and engineers.

She highlights how Building Transparency is involved in enabling low-carbon procurement of build-ups. As a non-profit, the company provides open-access tools and data in the form of a toolkit called the Embodied Carbon in Construction Calculator (EC3). The tool supports the policies from the public and private sectors concerning the disclosure of carbon data, such as EPDs (Environmental Product Declarations) that enable users to set carbon targets and later achieve them. It also lets its users compare manufacturers and source low-carbon options for their projects. Stacey says that the use of the tool in multiple projects across Washington state has brought about a considerable impact on building products and material manufacturers in lowering their emissions, be it concrete or carpets.

Kathleen Hetrick : Buro Happold

Kathleen Hetrick, WELL AP, LEED AP, is an Associate at Buro Happold and a Bloomberg Fellow at the Bloomberg School of Public Health, John Hopkins University. As part of Buro Happold’s sustainability team in Los Angeles, Kathleen combines her passion for regenerative design with a technical background in architectural engineering to lead sustainable design processes on a wide range of projects. She is also involved in the company’s thought leadership activities including corporate sustainability plans, purchasing guidelines based on embodied carbon, and so on.

She begins by stating how conversations around carbon and emissions have long been only in the realm of MEP engineers and not Architects/Designers because such aspects leaned much towards the operational side of buildings. Ever since the idea of embodied carbon started gaining traction, everything from structure and facades, to carpets and ceilings are now part of the ‘carbon conversation’. Going beyond that, construction and demolition waste is also a part of this conversation, owing to how critical each phase of a building’s life cycle can be in terms of emission intensities. She emphasizes the importance of projects, organizations, and their role in being mindful of their emissions, as it is not just a carbon story, but also a human health and environmental justice story. She insists that the problem is pressing and is not just localized to the United States, but rather the world over.

Kathleen goes on to throw some light on societal issues and environmental justice: she talks about how racial segregation and disparities in American cities result in people of color being more impacted by construction and extraction-related pollution. She insists that the problems associated with emissions are not limited to being environmental alone.

Projects don’t have to employ mass-timber construction to reduce embodied carbon; she says that it really comes down to the way you design, the way you construct, and more importantly the materials you procure, all of which play a role in bringing down embodied carbon. She mentions that it is even possible to slash emissions way into the project by making smarter decisions about material procurement. On both ends of the spectrum, be it a small firm starting out, or a large organization with a diverse portfolio, just being smarter about design decisions, optimizing structural systems, and making more informed material choices can all contribute to lowering your emissions. Kathleen further adds that it need not necessarily be only during the beginning of the project, and such choices could be made during any project phase.

Kathleen talks about how architects and designers could push structural engineers and contractors for material and build-up choices that are low on emissions. She says that more and more building products and materials nowadays have EPDs and that design and specification choices must be made with a target GWP to attain. Further, she talks about technological innovations in making clean and green building products, in manufacturing hubs powered by renewables, using less carbon-intensive processes. She mentions how tools like EC3 could be very handy in choosing material combinations that minimize emissions, and enable making more responsible material decisions. She insists on how local businesses and communities could benefit from a project from an emissions point of view, and how responsible specifications for a project could go a really long way in mitigating human and environmental health risks.

James Bowles: Freeform / Zero

James is a 4D planning specialist with a background in engineering and construction. He runs a 4D planning consultancy Freeform and leads the global industry group Zero which is focused on embodied carbon. Having worked on a wide range of projects, James has 22 years of project delivery experience in the UK and beyond.

James primarily focuses on people and industry groups, in bringing people together for a change in the attitude towards embodied carbon. Zero, their young industry group, envisions a completely decarbonized building industry. Their mission is to raise awareness, particularly outside the usual bubble of the AEC space, in getting people to make better decisions about embodied carbon. Zero aspires to become a global hub for people who want to learn more about and contribute to mitigating problems around carbon emissions.

James points out that it shouldn’t fall on just one sustainability consultant or an organization’s sustainability team to learn more about the impacts of emissions and work to resolve them.

He says it is all of us who should do more towards this subject and it is one of the founding principles of their industrial group. He believes it is possible to make a very substantial impact by collaborating and sharing knowledge on decarbonizing construction, rather than as individual organizations. Zero will be running social media outreach campaigns and has already established a mentor program to invite more people to their cause, with a focus on people with engineering, construction, and project management planning backgrounds. They aspire to get as many as a million people in the industrial group in 5 years.

James talks about the playbook that the group is developing to bring about educational outreach, hackathons, presentation events, seminars, and so on to collaborate and share ideas on decarbonizing buildings. He talks about the diverse kinds of backgrounds: architects, engineers, planners, project managers, quantity surveyors, etc. that people in the industrial group are from, working with a focus on not just materials and methods, but on education and communication, how to bring these ideas to the forefront to engage with people. Over the course of developing the group, James says that the industry group has representation everywhere and they are working towards bringing a lot of information on carbon-cutting available to people from all these backgrounds.