The building design and construction industry has an embodied carbon problem. The built environment generates 42% of annual global CO2 emissions, according to the International Energy Agency. Of those total emissions, building operations are responsible for 27% of annual global emissions, while embodied carbon emissions—the greenhouse gas emissions generated from the manufacturing, transportation, installation, maintenance, and disposal of building materials—are responsible for 15% of annual GHG emissions.
Unlike operational carbon which can be reduced, embodied carbon is fixed. Meaning once a building is constructed there is no opportunity to reduce its embodied carbon—it’s irreversible.
To mitigate the climate-damaging problem of embodied carbon today requires the combined efforts of the public and private sector.
RECENT PUBLIC SECTOR DECARBONIZATION INITIATIVES
In the public sector, recent federal government initiatives are aimed at growing the market for lower embodied carbon building materials and reducing levels of embodied carbon in federal buildings by prioritizing the use of low carbon materials in the construction and renovation of these buildings.
The U.S. government is the largest purchaser of goods and service in the world, with annual purchasing power of over $630 billion. Launched in 2022, the Buy Clean Task Force and initiative was created to harness some of that purchasing power to promote the use of low-carbon, made-in-America construction materials.
As part of this initiative, the General Services Administration is proposing a “substantially lower” standard for materials and products as defined by a global warming potential. This is the first time the federal government is prioritizing the use of American-made, lower-carbon construction materials in federal procurement and federally funded projects.
The Buy Clean Task Force was charged with three tasks: first, identifying construction materials and products with the greatest amount of embodied carbon to help prioritize lower embodied carbon materials for consideration in federal procurement and federally funded projects; second, raising the level of transparency of embodied emissions through supplier reporting of environmental product declarations (EPDs); and, finally, launching pilot programs to boost federal procurement of cleaner construction materials.
Building on this initiative, a Federal-State Buy Clean Partnership was introduced last March, with 13 states committing to prioritizing “efforts that support the procurement of lower-carbon infrastructure materials in state-funded projects, and to collaborate with the federal government and one another to send a harmonized demand signal to the marketplace.”
More recently, the GSA launched a pilot program of new requirements for the procurement of substantially lower embodied carbon construction materials in GSA projects funded by the Inflation Reduction Act. The IRA provides $3.375 billion for GSA to invest in federal buildings to help reduce carbon emissions and catalyze innovation. Of that amount, $2.15 billion is earmarked to procure low-embodied-carbon materials for construction and renovation projects.
According to the GSA, these investments will help leverage the federal government’s purchasing power “to spur markets for products that have substantially lower levels of embodied greenhouse gas emissions associated with their raw materials, transportation, and manufacturing—all of which occurs before GSA purchases the products.”
HOW THE PRIVATE SECTOR COMES INTO PLAY
To significantly reduce embodied carbon in the built environment, the private sector must also do its part to decarbonize buildings.
This is critical, considering that as much as 50% of a new, energy-efficient building’s emissions come from embodied carbon, according to the World Business Council for Sustainable Development (WBCSD). As the construction sector works to address the embodied carbon problem, tracking and reporting these emissions must improve so that the industry’s progress can be validly monitored. A report by the WBCSD and global sustainable development consultancy Arup estimates that less than 1% of building projects currently calculate and report their full carbon footprint.
Meaningful reduction in embodied carbon will require the combined efforts of private-sector stakeholders in every link of the building construction value chain.
Building material manufacturers should focus on research and development to create products with lower embodied carbon. Specifically, manufacturers should work to physically reduce scope 1 and 2 emissions when producing building products.
This can be done in a number of ways. Manufacturers could invest in on-site renewable energy like solar PVs or wind, if viable. They could also work with their utility provider to buy direct renewable power or contract with renewable energy developers to secure a power purchase agreement or virtual power purchase agreement to secure direct renewable power.
Manufacturers could also consider a “sleeve transaction,” which would allow the manufacturer to have a third party try to get a better price from the energy supplier; sleeve transactions have become significantly easier to obtain in the past few years. Building product manufacturers should avoid renewable energy credits and carbon offsets, as these are the last possible levers to pull.
Manufacturers should also work to publish EPDs to provide transparent data on the cradle-to-grave environmental impact of the products they produce. Architects and designers can use these EPDs to specify low carbon construction materials in their building designs. Using EPDs and other resources like this, building design professionals can more easily select lower embodied materials, optimizing building design to help conserve natural resources, improve building performance, and help promote a more sustainable built environment.
Contractors also play an essential role in helping to decarbonize the built environment. Every phase of the construction project life cycle presents contractors with opportunities help lower embodied carbon. This includes sourcing lower embodied carbon materials and establishing low-carbon procurement requirements with trade contractors.
The industry can also effect positive change by increasing awareness of embodied carbon. Educating all links in the construction value chain on the impact of these carbon emissions, the resources available to help identify and select lower embodied construction materials and the power of circular and efficient design and construction will go a long way in reducing these harmful emissions in the built environment.
As climate change continues to worsen, lowering embodied carbon is now more than ever before a critical imperative in the construction industry. To make meaningful progress in reducing embodied carbon and achieving climate targets will require the collaborative efforts of both the public and private sectors in prioritizing the selection of lower carbon materials. These combined efforts will help drive mass adoption of more climate-friendly building materials, which will reduce carbon emissions throughout the life cycle of buildings and pave the way to a greener, more sustainable built environment
ABOUT THE AUTHOR
Brent Trenga, LEED AP BD+C, WELL AP, is Director of Sustainability for Kingspan North America. Since 2015 he has led Kingspan North America’s material health and transparency program. He also leads Kingspan’s global Planet Passionate 2030 program, supports strategic planning for the company’s business development group, and provides insight to the entire company on sustainability initiatives.
