Hosts: Stephen Lacey & Katherine Hamilton
Guest: Christine Williamson | Founder | Building Science Fight Club
Category: ☁️ Carbon Reduction
Podcast’s Essential Bites:
[7:43] “A lot of what we really talk about is not just energy efficiency, and environmental responsibility, but risk, and primarily the risk of water related failures in our buildings, stuff like rot, corrosion, mold […]. And when it comes to discussions of energy, a lot of the design decisions that we wish to consider to advance our climate goals can unintentionally make our buildings less durable, and less healthy. Now, those things aren't always in opposition to each other. […] But they're also rarely in perfect harmony. And that's where Building Science can really help.”
[12:06] “In some ways, understanding design and building science and construction better equips designers to make […] early decisions in the design process that are less likely to get value engineered […] out of a project later on. […] And I think one of the challenges that we've had […] particularly with our green rating systems, or these incentive programs to encourage this kind of behavior is that we've essentially deputized architects to solve this problem by themselves. And we, I think, are not really acknowledging how big a role the owner plays in this. […] And I think […] that there are much, much simpler commitments that we can get out of people publicly, whether they're mandatory or not, then then the current very confusing approach that we take right now.”
[15:22] “Residentially, we're actually doing pretty well […] with energy improvements. […] We've actually made substantial progress. […] There's a kind of census, but for buildings that the government does every few years, and we actually have some pretty good data on energy use in buildings in the aggregate. And over the past 30 years our residential buildings have gotten much more energy efficient. […] So for example, in 1993, the average residential building […] used 55 kBT use per square foot. And by 2015, which is the most recent year that we have data that was down to 38 kBT use per square foot. And that is a really big deal. […] Now that's per square foot, though, the average home of course, has also gotten larger, and we have fewer occupants per home on average than we used to. But what's really interesting is that the downward trend holds even when we account for larger homes and fewer occupants per home. So the average home uses less energy as a whole. And the average person uses less energy at home by about 25%. […] We have much better windows than we used to much, much better, our homes are more airtight. Our homes are better insulated, and the appliances and mechanical systems inside our homes have also gotten more efficient. So it's really the combination of those factors that have made us see really excellent results […] when it comes to homes.”
[19:50] “Unfortunately in commercial construction, we are really struggling. The average commercial building uses about the same amount of energy per square foot as it did in the early 90s. […] We use about 80 kBT use per square foot, which is about twice as much energy per square foot as the average home. And that is primarily related to glazing, and ventilation. Even the best glass performs about as well or worse than the worst walls. And we use a lot of glass in commercial buildings. We also ventilate commercial buildings at much, much higher rates than we ventilate our homes. And when we bring in lots of outside air, we have to condition that air and that requires energy. And I think a really helpful distinction to make here is that we optimize interior conditions for comfort in residential buildings. But we optimize commercial buildings for productivity. That is a huge difference. And whereas we have a lot of market forces that make energy improvements very appealing in the residential market, those same market forces don't exist the same way in commercial buildings.”
[26:30] “When it comes to actual energy consumption in buildings, the three most important factors related to the enclosure design, so the layers that separate the inside from the outside, […] are how much glass is on the building. […] Number two, how airtight is the building. And number three, how well insulated is the building, including stuff that we call thermal breaks, or thermal bridging, where we have large structural elements that interrupt the insulation. […] And the […] non enclosure related factor that contributes enormously is the ventilation rates. […] So everything is sort of downstream of those things.”
Rating: ⚡⚡⚡
🎙️ Full Episode: Apple | Spotify
🕰️ 57 min | 🗓️ 09/30/2021
✅ Time saved: 55 min
