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To Address Climate Change, Architects Must Tackle Embodied Carbon

If the building industry is really going to tackle climate change, we can’t simply talk about energy and building performance. It must be a much broader discussion, encapsulating all aspects of what we do. The shift to a focus on decarbonization over energy performance is clearly happening. Wall Street is pushing publicly traded funds and companies to establish carbon-reduction goals as part of their environmental, social, and governance (ESG) reporting. They’re publishing the results, and analysts are reporting on their progress. That alone has changed the conversations we’re having with larger clients. At the same time, universities, cities, and municipalities are also moving to better understand how to mitigate their carbon footprint. New codes and local ordinances are mandating higher standards.

As an industry, we need to evolve our approach. Designing around performance, the predicted energy intensity (pEUI), was a necessary place to start. It was easy to understand and could be addressed with cost-effective strategies that had a measurable payback over time. A number of software tools were available and accessible, and design firms could work with engineers to figure it out and make at least some measurable progress. After 13 years, firms reporting their results in the AIA 2030 Commitment cut operational energy use in their projects by an average of 50%—which represents progress, even if it does fall far short of the program’s target.

Carbon is a different story. To date, we have been measuring building performance, which has given us an understanding of operational carbon emissions. But to have a full picture of the carbon footprint of a building, we need to measure embodied carbon, which are the emissions associated with the extraction, manufacturing, and transport of building materials. While building performance metrics are contained and easy for designers to influence, embodied carbon is diffuse, coming from many sources throughout the building lifecycle. It’s hard to measure, and its calculation is dependent on more stakeholders. This means that if the industry is going to master carbon, we’ve got to work differently and update our definition of sustainable design.

The first thing we need to do is understand where we are. At this point, we don’t have widely accepted embodied-carbon baselines to measure against or targets to shoot for. There’s not a lot of data out there on embodied carbon, and the information that is available can be hard to find. There has been progress in recent years—and several companies have developed tools, including Tally, EPIC, and EC3—but we need to develop an industrywide database to set easily understood benchmarks.

Interiors need to employ circular supply chains, and incorporate recycled and salvaged materials to limit embodied carbon. Designers should give preference to materials and finishes with Environmental Product Declarations to better understand their environmental impacts. Photo: LPA/Costea Photography.


We also need to take a more rigorous approach to building and material reuse. Renovations typically save 50% to 75% of embodied carbon, compared with new construction, according to a study by the Rocky Mountain Institute. Too many times we tear a building down, take its pieces to the dump, and erect a new structure. Retrofitting and making existing buildings more efficient needs to be a huge part of our carbon strategy.

When we do build, we need to think in a new way and ask different questions: Are our building materials highly recyclable? Is the building highly resilient? Can the building be deconstructed after use or easily readapted to a new use? Can the supplier take used building materials and feed them back into its manufacturing process? All four questions are strong indicators of where the design should be going.

To make better choices, we need to evolve our understanding of how individual buildings contribute to carbon emissions. It will take an integrated approach to every project, involving engineers, interior designers, and landscape architects from the start of the process. Only by talking about carbon holistically from the earliest stages can we achieve meaningful results and reduce the carbon emissions generated by the building and construction industry.

When we focus on pEUI as our main metric for measuring performance, the key players are architects and mechanical and electrical engineers. The strategy is simple: optimize the envelope and systems to reduce the building’s energy demand and then look to add renewable sources to offset any remaining loads. But when you talk about carbon, everyone has to be at the table. For starters, you need the structural engineers. On some projects, the foundation and structural system can account for 50% of the overall embodied carbon. Efficient structures and the right materials can have a huge impact on a project’s total carbon footprint.

Landscapes are an underutilized resource for carbon reduction via biosequestration. Photo: LPA/Costea Photography.


Landscape architects should also play a larger role. While architects and engineers always talk about “doing less bad,” landscape design can have a positive effect, employing planting strategies that sequester carbon, offsetting some of the carbon emissions associated with the building while creating healthier environments.

Interior designers are absolutely necessary to discuss materials and help determine the appropriate amount of built space for the project. Understanding the client’s larger goals can help right-size the building and explore ways to build less. We should also be considering how long these interiors will last. Over a 60-year lifespan, cyclical interior fit-outs can add more embodied carbon than the structure and envelope of a building, studies show. Are we creating interiors to be deconstructed? Are we creating them to be recycled? Are we fully leveraging recycled or salvaged materials? 

Designing around these questions will pay huge dividends when we bring carbon into the discussion in addition to building performance. But we can’t have these discussions halfway through a project. By then, reversing decisions that have already been made is costly and creates delays.

In recent years, we’re seeing movement within the industry. Associations are rallying the industry to focus on reasonable targets, such as SE 2050, which calls on structural engineers to target zero embodied carbon by 2050. Mechanical and civil engineers are taking up similar targets, demonstrating the importance of the cause.

Despite a growing awareness that carbon is an important metric to track, the complexity around it, combined with a lack of regulation, is creating hesitation. We need to get past the uncertainty and recognize that zero carbon is not simply the right thing to do, but an imperative. It’s in all of our best interests to work with clients from the start of the process to address what we, as an industry, know is the biggest issue of our time.

Featured image: The Environmental Nature Center and Preschool, in Newport Beach, Ca., won a national AIA COTE Top 10 award in 2020. The LEED Platinum building has PV panels, which are designed to produce 105% of the net energy required to run the school. Photo by Costea Photography, courtesy of LPA.


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