[Note: To watch segment 2 of Chris Magwood's lecture, please click here.]
Magwood found that the choice of building materials made a whopping difference in whether a given building was a net carbon emitter or a net carbon drawdown, from over 200 tons of embodied carbon in the worst case to a net drawdown, or storage, of over 130 tons using the best materials. He was still skeptical about his results, but when he began to share his results, everyone agreed, “Yep, those are the numbers.”
High Energy Efficiency Paradox
Magwood also found a surprise when he looked at the impact of using high EC materials in an effort to reduce the operational energy of a given building. “When I looked at energy efficiency, if the insulation has a high carbon footprint like foam, you drive up the EC of the building. So we’re trying to drive carbon down, but with foam, you get a big jump in the carbon footprint. The opposite happens when you’re using plant-based materials. So using more plant-based materials is good, as opposed to bad.”
In fact, instead of using lots of foam to get high energy efficiency in operations, Magwood found you would get less carbon-intensive results by just building to code using standard materials, the best of the worst at Home Depot.
“This result is devastating for people who’ve been making energy efficiency the primary goal. But it’s not the right thing to do if you’re not using the right materials—people are shouting at me at passive house conferences, ‘No, no, no."
Eliminating 25 Coal Plants
What did these numbers amount to across a whole country? Magwood was forced to use numbers from the U.S. because the Canadian government does not track building statistics as a result of Conservative cut-backs.
If all residential building in the U.S. happened at the worst case level, the resulting embedded carbon emissions would be 54 million tons, the equivalent of the output of 15 large coal plants. On the other hand, if these same buildings were built using the best materials, the result would be the drawdown of 36 million tons of ECs, the equivalent of taking 10 large coal plants offline. The net effect of using the best materials would therefore be the equivalent of removing 25 large coal plants (15+10). By way of comparison, “In Ontario, we shut down 6 coal plants, and it was the biggest reduction in emissions ever in North America.”
Magwood said his findings were exciting in part because they were “eminently doable. Lots of other industries emitting on this scale face an existential threat: you’ve got to stop what you’re doing. In building sector, we don’t have to stop building, we just have to build better, and we can be part of a solution by continuing to build in a really smart way. A message you can take to industry, we’re not asking you to stop, join in, be a hero for the climate, keep doing your business, just do it smarter, think about this stuff before you put it in.”