Embodied carbon in buildings represents 11 percent of total global emissions, but what is it and why should architects be considering it in their building design? Embodied carbon is the greenhouse gas emissions associated with a building materials’ lifecycle from extraction to production to transportation to construction to demolition. Each point of a material’s lifecycle offers an opportunity to lower the amount of carbon emitted by the process; isolating and tackling these opportunities offers architects a chance to play a critical role in reducing the built environment’s impact on climate.

A lot of work has already been done to make buildings more efficient and lower the amount of “operational carbon” emitted by a structure. Operational carbon comes from the energy used to power a building’s lighting, plug loads, heating, cooling, ventilation systems, etc. after it has been constructed. Embodied carbon, in contrast, is focused on the materials used to construct the building, such as steel, concrete, and aluminum. Concrete, the second most consumed material in the world next to water, is solely responsible for 8 percent of all global emissions. Figuring out how to lower the carbon footprint of the concrete lifecycle is imperative to meeting global emission reduction goals.

Various technologies have been developed to modify or replace some of the carbon-intensive materials, such as concrete. Designing different ingredient combinations can reduce the amount of CO2 emitted by concrete. For example, mixing industrial cement with mineral compounds such as calcined clays, fly ash, or blast-furnace slag can produce low-carbon concrete. The challenge that lies ahead is adoption of these technologies. Widespread use of these materials will require educating and motivating those in the AEC industry to implement them. Through its Knowledge Communities—member-led groups focused on specific topics, many of which are related to climate and equity—the BSA is taking on this challenge and partnering with other members of the AEC community to work towards the implementation of low-carbon concrete and steel technologies. One of these Knowledge Communities, the CLF Boston/Northeast Hub, is currently working towards convening multi-disciplinary members of the AEC community to identify pathways and roadblocks to implementing low-carbon concrete technologies in the Boston area. Learn more.

In addition to working on low-carbon concrete adoption, the BSA is also championing experimentation with mass timber, a low-carbon alternative to concrete and steel that has the potential to reduce a building’s carbon footprint by as much as 39 to 52 percent. Mass timber is produced by joining pieces of wood together to form strong, fire-resistant structural materials. The Boston Planning and Development Agency, in partnership with the BSA, has awarded numerous grants to support mass timber innovators through the Boston Mass Timber Accelerator. In February, three awardees were each granted $25,000 to help further the implementation of mass timber in the Boston area. Learn more about this program.

To learn more about embodied carbon, consider participating in what is currently the AIA’s most popular continuing education course: Embodied Carbon 101.

To get involved in the BSA’s Knowledge Communities or learn more, click here or email: [email protected].