Sustainability Glossary: Embodied Energy
As part of the Metropolis Perspective: Sustainability special issue, we asked experts to provide refreshed definitions of key sustainability concepts.
In 1978, ten years before scientist James Hansen warned Congress about the severity of climate change, architect Richard Stein co-published a paper in Science about energy consumption in architecture. In it, Stein reported that most of the consumption in buildings was operational energy—that used for heating, cooling, and lighting. The remaining 10 percent was embodied energy—what is required to extract, manufacture, transport, and assemble a building’s constituent materials.
Despite embodied energy’s relatively small proportion, Stein concluded that reducing embodied energy expenditure was critical, and he made a series of recommendations: establishing embodied energy limits in building codes; reducing the amount of structural materials in buildings; and rehabilitating old buildings instead of creating new ones, which would improve both energy consumption and labor conditions.
Today the proportion of embodied energy in buildings has increased to more than 40 percent of energy consumption. And zooming out to a broader scale, we know that buildings have a huge global impact. According to the United Nations Intergovernmental Panel on Climate Change, by 2050 a third of global carbon emissions (and roughly a third of global energy consumption) will come from constructing—not operating—buildings and infrastructure.
It is clear that addressing embodied energy is a critical part of the climate change challenge that Hansen warned about, and there are some immediate steps that architects can take, such as designing with wood and mineral wool instead of steel and polystyrene. But more fundamentally, the concept of embodied energy allows us to examine the intersection of architecture and the environment with a fresh perspective. By considering the production of a building as an act of energy expenditure, architects might start designing systems that extend beyond the boundaries of their walls and facades. They might see buildings as temporary formulations of matter, energy, and labor that are connected to other formulations preceding and following the life of a building. And embodied energy might offer a framework for designing—or at least accounting for—many invisible yet essential aspects of the built environment, including embodied carbon, embodied water, and embodied labor. While digital and visual information abounds, physical but invisible impacts are more important than ever.
DAVID BENJAMIN is a professor at Columbia GSAPP and founding principal of New York research and design practice The Living. He edited the 2017 book Embodied Energy and Design: Making Architecture Between Metrics and Narratives (Columbia Books on Architecture and the City/Lars Müller Publishers).
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