These are troubling times for conscientious architects and builders. A 2019 report from the U.N. Environment Programme offers a “bleak” outlook in progress toward controlling greenhouse gas emissions and holding off permanent climate change, and buildings have a lot to do with it.
The agency’s Emissions Gap Report—which estimates the difference, or gap, between actual and future emissions and levels that make goals of the Paris Agreement possible—shows that global emissions are going up by about 1.5% per year. It will take a 55% reduction in emissions in the next decade to hold global warming to 1.5°C, a 25% reduction to limit warming to 2°C.
Buildings are a major contributor to the problem. An estimated 39% of global CO2 emissions can be traced to the building sector: 28% to operate (heat, cool and power) buildings and another 11% in materials and construction.
Forward-looking builders have been pinning their climate hopes on designing buildings that use less energy. By lowering energy consumption with more insulation, better air sealing and high quality windows, less fossil fuel gets burned. People who live in those houses won’t spend as much money to heat and cool them, and they’ll be more comfortable. More to the point, more efficient houses mean fewer carbon emissions in the atmosphere. This is helpful for long-term carbon reductions, but not in the near term. That’s the rub. The time frame to check the global carbon problem is much shorter than the carbon benefits that high-performance building will provide over the next decade or two. The embodied carbon in these new super efficient buildings is “front-loaded,” meaning that all of it occurs when the building is erected.
Increasingly, the focus is on embodied carbon in construction—the greenhouse gas emissions associated with extracting, manufacturing, and transporting the materials needed for building. Architecture…