Feature image: Heidi Creighton helping build a pedestrian bridge in rural Panama. Photo courtesy of Buro Happold.

The United Nations Department of Economic and Social Affairs estimates that by 2050, 68% of the world’s population will live in urban environments. As the song goes, “we are living in a material world,” and much of this urban fabric is shaped by those of us in the built environment sector.

A large part of my professional role is to reduce the carbon footprint of the built environment in both operational and embodied carbon. Architecture 2030 research shows that the built environment is responsible for about 42% of annual global CO2 emissions. There are exciting opportunities and synergies for our industry to innovate and create healthier jobs and spaces as we all race toward our collective net zero, or even net positive, carbon goals.

Operational and embodied carbon

Operational carbon strategies are focused on lowering energy use intensity (EUI) and carbon intensity through efficient building systems, high-performance facades, behavioral changes and renewable energy generation. Decarbonization of our utility grid will also play a critical role in reducing the CO2 emissions of the built environment. Creating all-electric buildings will further reduce our dependence on fossil fuels (used for space and water heating, as well as commercial cooking needs) and is an additional key step toward the decarbonization of our building stock.

Embodied carbon strategies today tend to focus on the largest volumes of materials—which, for new construction, are the project’s foundation, structure and enclosure. A key tool for understanding the embodied carbon in building materials is Environmental Product Declarations (EPDs), which serve as material “nutrition labels.” The relevance and number of EPDs has grown rapidly, with a majority of EPDs available for concrete, finishes, asphalt, insulation and steel. The quality and comparability of the emissions data for construction materials and products continues to expand, offering critical information for the decarbonization of our material supply chain.

LEED debuted in 1998, and our industry has made significant strides in reducing our operational carbon footprint over the past quarter-century. The operational carbon generated from the daily use of a building will be decreased over time, thanks to ongoing energy efficiency efforts and grid decarbonization. LEED v4 incorporated whole-building life cycle assessment, as well as a more holistic approach to the Materials and Resources credit category. These strategies are a critical step in helping owner and design teams evaluate the embodied carbon impacts of material choices on human health and the environment.

Two colleagues give a presentation on collective impact. — A Collective Impact event. Photo courtesy of Skanska.

1550 on the Green: Texas

A focus on embodied carbon can be seen at 1550 on the Green, the 28-story office tower in Houston, Texas, that is targeting LEED Platinum and WELL Platinum certifications. Bjarke Ingles Group (BIG) as the designer, Skanska as the developer and contractor, and Walter P. Moore as engineer are all working closely together to reduce the embodied carbon by approximately 45% compared to baseline buildings. The primary contributor to this reduction is a focus on cement replacement in the concrete. For example, the use of low-carbon concrete in the project’s foundations is equivalent to taking 172 cars off the road for one year.

In addition, Skanska was able to reduce the amount of material necessary for different components. Notably, the project saved 700 cubic yards of concrete, or 70 truckloads, by reducing the slab thickness of the pan-formed system by 3/8 of an inch. This limited the amount of time that trucks servicing the project were on the road, which, in turn, contributed to improved air quality. For 1550 on the Green, a focus on ambitious embodied carbon goals created a substantial community benefit in cleaner air to breathe.

A high-rise building with terraces that incorporate greenery. — 1550 on the Green. Photo courtesy of Skanska USA.

Santa Monica City Hall East: California

In addition to embodied and operational carbon, we need to be concerned about the chemicals embedded in our building products. The International Living Future Institute (ILFI) maintains a red list of toxic chemicals that are prevalent in current building materials. These “worst in class” chemicals, along with other toxic materials, are harmful to human health and the environment and can be replaced with safer alternatives. Nontoxic, local and/or natural materials are inherently lower in embodied carbon and are better for all those along the material supply chain, from extraction and harvesting through manufacturing, transportation, installation and occupation to end of life.

Santa Monica City Hall East (formerly “The City Services Building”), which I worked on while at Buro Happold, is an all-electric, net zero energy and net zero water municipal project that is ILFI Living Building Challenge Ready and in its performance period now. Beyond being combustion-free and net zero, the project also had to meet the standards of the ILFI red list. The design-build team of Hathaway Dinwiddie, Frederick Fisher and Partners, and Buro Happold led the charge on the ambitious materials goals.

The team vetted over 1,000 products, approved and installed 800 unique products, trained 400 workers and onboarded 40 trade partners. Cost premiums were nominal, embodied carbon was reduced and manufacturers where overwhelmingly willing to work with the team. Some manufacturers changed their products permanently to meet the standards after we did our due diligence and advocacy for this project. The vetting, training and advocacy coming from projects like this help signal to the material supply chain and the broader industry that there are better, healthier and safer alternatives.

Projects pursuing LEED certification will find that in LEED v5, which is currently in its public comment period, new prerequisites are being introduced for the Materials and Resources category: Assess Embodied Carbon and Planning for Zero Waste Operations. Every credit and prerequisite in LEED v5 has a connection to decarbonization, quality of life and/or ecological conservation, showing USGBC’s commitment to a LEED program that is relevant, forward-thinking and the most impactful yet.

Construction workers bolting a large table to a floor. — Santa Monica City Hall East under construction. Photo courtesy of City of Santa Monica.

Community planning in Los Angeles

In our urban centers, we must strive to think beyond individual buildings and consider the wider region and ecosystems. Here in Los Angeles, I had the unique opportunity to work on L.A. County’s first-ever sustainability plan, coined OurCounty. Our team meaningfully engaged with communities through 11 participatory workshops in neighborhoods throughout all five county districts. The discussions were inclusive of the perspectives of low-income communities, where we heard and collected close to 6,000 comments that directly informed the final plan.

For example, one resident commented, “Thank you for taking such a strong leadership [position] on climate action, the most critical challenge of our time! To truly reach net zero carbon by 2025, fossil fuel use in buildings will need to be completely phased out and not simply mitigated.” This comment influenced the language used in one of the plan’s strategies. Broad support for the plan was also received from many nonprofits. They were in favor of a commitment to a clean economy through a just transition for displaced workers by providing meaningful job training and employment opportunities.

The ambitious and bold plan focuses on those communities that have been disproportionately burdened by environmental pollution, such as oil fields and refining facilities, manufacturing facilities, waste disposal sites and heavy transport infrastructure. The ports of Los Angeles and Long Beach handle approximately 29% of all containerized international waterborne trade in the United States. The plan is organized around 12 goals that cut across the environment, equity and the economy, designed to help the 88 cities and unincorporated areas of L.A. County toward sustainable outcomes.

Three people in discussion around a table. — OurCounty stakeholder engagement. Photo courtesy of Buro Happold.

Social equity and fair labor

In our industry, low-cost bids often win the job. Unfortunately, this can lead to cheap materials, as well as low wages and poor working conditions for our construction crews, truck drivers, and mine, field and factory workers. The building sector has a complex supply chain. As we scrutinize the carbon-intensive parts of this supply chain, we are likely to find forced labor. Therefore, focusing on lower carbon emissions and transparency in our supply chains will help eliminate forced labor and improve working conditions and wages.

To enact change, there are resources such as the Design for Freedom Toolkit that provides information, sample specification language, a tracking spreadsheet and a supplier outreach letter. Another impactful approach is to pursue one of the LEED pilot credits that is focused on social equity within the project team, supply chain and/or the community. We have an incredible opportunity to lead the industry to a humane materials supply chain.

Tips for green building professionals

There are exciting opportunities as we build toward a resilient and circular future. Here are some suggestions for sourcing better products and reducing the carbon impacts of your work:

Do the analysis and use the many available tools to model, track and measure operational and embodied carbon. You will make more efficient and impactful decisions with this information.
Prioritize carbon alongside costs. By looking at these metrics together, you will find big carbon wins with little to no cost premiums.
Engage with nonprofits focused on lowering carbon to learn, give back, network and create partnership opportunities. As an example, join USGBC California on May 23 for the California Green Building Conference in South Los Angeles, where innovation meets sustainability, uniting advocates and companies statewide to shape a greener California.
Demand EPDs. Signal to the material supply chain that transparency and low carbon materials are necessary.
Set aggressive carbon goals and budgets for your projects early. Bring creative teams along with you to come up with innovative solutions.
Find partners. None of us can do this alone, and partnerships will help scale leading-edge innovations and solutions.

The end result of a keen focus on carbon and supply chains is improved resilience for all, including better air quality for our communities, higher wages, safer conditions for workers across the supply chain, and healthier indoor air quality for our construction workers and building occupants—and for you, the legacy of helping make the world a better place for all.

The social benefits of lowering carbon