The Decibel - The problem with building more housing

Episode Date: August 23, 2023

Canada needs a lot of housing – and the Liberal government is making this a priority at their cabinet retreat this week. But there are concerns that if we keep building new homes using current materials and practices, it could lead to a spike in our greenhouse gas emissions.Luigi Ferrara is the chair and CEO of the Brookfield Sustainability Institute, which looked into this issue. Today, he tells us why current building practices cause high emissions, and how homes could be built differently – and retrofitted – to become more sustainable.Questions? Comments? Ideas? Email us at [e-mail]

Prime Minister Justin Trudeau is holding his Liberal cabinet retreat in Charlottetown this week. And one of the big issues they're focusing on is the housing crisis. As our population continues to grow, the supply of housing just isn't keeping up. So Canada needs to build a lot of houses. By 2030, we need 5 million new homes. That's according to a report from RBC and the Brookfield Sustainability Institute. But there might be a problem with that. A climate problem.

According to that same report, if the homes are built using current practices and materials, it will spike our greenhouse gas emissions. Luigi Ferrara is the chair and CEO of the Brookfield Sustainability Institute, and he's the dean of the Center for Arts, Design, and Information Technology at George Brown College. Today, Luigi tells us why Canada's current building practices cause such high emissions and how we can build things differently going forward. I'm Mainika Raman-Wilms and this is The Decibel from The Globe and Mail. Luigi, thank you so much for joining me today. Oh, thank you for having me here.

So we know that Canada needs a lot of housing, but building those houses might spike our greenhouse gas emissions. And your report says that if we keep building the way that we are doing these days, our emissions will increase by 18 million tons every year, which seems like a lot. But can you put that into context for me? Is it a lot? It definitely is a lot.

And if you just imagine just the simple fact of potentially creating four to five million new homes for Canadians, you could imagine the impact of the existing homes that we have in the country. This is a significant addition of new housing stemming from growth in families, generational turnover, but more importantly, from immigration that is coming to this country. So if you see this impact coming, you have to plan for it and you have to plan to do housing differently. Because if we keep building as we have been building over the years, you know, we're building to standards of the 20th century, where we had what seemed like unlimited energy. And we had a much smaller population and we had much more space to house the population.

We're in a very different situation in the 21st century. And in the future, we're going to need to start thinking about how to live more simply, more in tune with nature. So every century has its own way of living. And we're starting to reimagine and redefine how we're going to live in this century. So how much do existing buildings actually contribute to our greenhouse gas emissions today? Yeah. So globally, the figure is around 40%.

I think about 28% is operations of the buildings once they're built. And then the 12% is the embodied carbon that goes into building the buildings and making the materials and transporting them to the site. But, you know, there's an overlap between, you know, the different sectors. In the RBC report, we talk about the building sector being the third largest sector, because if you go by sectoral analysis, obviously oil and gas is big, and then transportation is another big sector, and then the built sector is the third. So really, they're kind of all interrelated, how much energy you use, how you construct your built environment, and the way you get around the cities. They're the big trifecta that impacts our greenhouse gas use. Right. So let's actually get into this then. So

why do buildings cause such high emissions? Can you help me understand what's happening? Well, you know, anytime you're creating something major and new, like, you know, highways, cars, etc., you're using a lot of resources, right? And to create those resources, you expend a lot of energy. So even just making the materials to make the buildings actually it takes a ton of energy, and then taking that material to the site, building that material, and then cladding it, and then heating the spaces that we're building, right? And just to think about it, you know, an average house, say, in 1950, the size of a house was 1,100 to 1,200 square feet. Now, average homes are, you know, sometimes in the order, you know, at least single-family homes of 22,000 to 3,000 square feet. Now, average homes are, you know, sometimes in the order, you know, at least single family homes of 22 to 3,000 square feet. And so with bigger homes, that means more space to heat and cool, you're saying? Absolutely. It's harder to run, more costly, more energy expenditure,

and not necessarily in use all the time, and often with by few users right you know that's a whole different utilization of the space of our geography and a consumption of land loss of land for food so it sounds like there's a lot of things like we have to think about going forward and so when we're talking about house emissions it sounds like you're kind of breaking it into two buckets right there's the emissions from the materials that build the houses and then there's also the emissions from heating and cooling those buildings can Can I ask you about bigger buildings though, Luigi? Like I'm thinking about the office towers that we're in right now, right? There's a lot of steel and windows that must take a lot to heat and cool as well.

Absolutely. And in some cases, those buildings are built less efficiently than even single family homes. They have tons of glass on their surface, whether there are office towers or condominiums. They're not very well insulated. And they're also used for limited periods of time, right? They're used in essence from nine to five. And since the pandemic, they're used even less. And so we are heating them. We are cooling them, mainly cooling them, because actually when you put people in them, generates so much heat that they often need to be cooled, even in cooler weather. And that costs a lot of money.

It expends a lot of energy. It puts out emissions into the atmosphere. And increasingly, they're going to be potentially empty. Work patterns are changing dramatically. It may mean that many of our office buildings need to be reimagined because some of them will be sitting empty. And any good sustainability planner will tell you the best way of moving forward is to reuse all your existing buildings and not necessarily build new ones because, you know, retrofitting the existing buildings, it means that you've got a lot of the embodied carbon already covered and you're just updating and reducing the energy costs of operating them and actually making them better utilized over time, right?

So, you know, rethinking how we're doing things, how we're planning our cities, turning them into mixed use zoning, as opposed to single use zoning, imagining that parts of an office building might have workplaces and parts might have living in them. That's a very big change from how we've been operating up till now. So let's actually talk about then how we would go about making these kinds of changes, because they do seem to be pretty significant changes. How could we build differently to reduce the emissions that we're talking about? So, for example, with the construction of a building, how could that be done differently? Well, I mean, you know, George Brown, with its Limberlost Place, has got a signature project that's reimagining just that. And you're talking about this Limberlost Place is this building that George Brown is constructing. It's a 10-story building that will

house our architectural technology and computer technology schools. And it's been designed, it's 10 stories, it's made of wood, has a totally new structural system. It's a net zero carbon building because wood is much less embodied energy and it has embodied carbon within it than, say, a concrete or a steel building. And when you say embodied carbon, that's just the carbon that's baked into the, but in the wood, essentially.

Absolutely. And in the processes, you know, you're just cutting it down, reshaping it and constructing with it as opposed to having to grind and heat and burn to make steel or concrete, which expends tremendous amounts of energy, right? So, you know, this building is showing the way of how we might build differently in the future. In fact, it also doesn't have a central cooling and chiller system. It's passively designed to absorb energy both in the solar voltaics, but passively in the solar chimneys, redistributes

the heated air throughout the building, lets it out when the building needs to be cooled off, closes the vents when the building needs to retain the heat. It's a smart building that is working with nature as opposed to trying to overcome nature by having these giant machines that cool in heat, right? So it's a totally new approach. And we're going to need to build a lot of those types of buildings moving forward. So our residential buildings, you know, may need to shift to this kind of construction. Certainly our office and institutional buildings might need to shift in this direction, or we'll need to find

ways to make, you know, concrete buildings less carbon intensive by curing the carbon, capturing and sequestering the carbon. You know, there's all sorts of technologies that are being developed. But mainly, you know, from a building design, the key thing is to respond to nature, to the sun, the wind, you know, being closed where you're going to lose a lot of heat and open where you can gain passive heat. Developing something that's been pioneered in Canada, which are double skins that actually create like a. What is that? It's almost like having insulation on a building using a gap with a second skin. So it's like wearing a piece of clothing.

Your building's wearing a jacket, in essence, and therefore it doesn't lose as much heat. It has a space for that heat to be trapped in. Like a double-paned window, but for the whole building. But for the whole building. Yeah, so as you said, it sounds like you actually need to kind of work with nature and make it fit in a way that you're not always fighting against the heat or against the cold, but finding ways to kind of integrate this together within the building. Can I ask you

about heat pumps, Luigi? Because I think we hear a lot about heat pumps these days. Can you tell me about those and how they might help? Well, they're actually already helping, and especially in Atlantic Canada. They're a little bit expensive at the moment, but they enable sort of the transfer of heat and cold to capture the heat and keep it in a building and then to release it as needed. And Canada has actually been pioneering this kind of technology. So heat pumps are a new way of trying to heat our homes and our buildings. But there are many, many technologies.

I kind of like an approach that I call smart sustainability, which uses digital technology to really optimize what you're doing with a natural and passive and with specialized technology like a heat pump. Can you give me an example of the digital technology? We designed a house a number of years ago called the Canoe Home for CMHC, Canada Mortgage and Housing Corporation. So it was a demonstration home. But, you know, the idea there is when we're in our houses, we're often only in like one or two rooms.

And yet we're heating the whole house. And often we're out of the house for large periods of time. use sensors and digital technology to sort of heat only the areas that you're occupying and then just keep the other areas cool enough not to sort of freeze, but not up to the level of human occupation. If all of us were doing that, we would significantly reduce the energy usage. And some people do that these days, right? But they have the thermostat on their phone. They've got a smart system in their house. Absolutely. So this is kind of using the

digital to be more sustainable. Also, if you think about it right now, we build buildings and then there's tons of garbage, right? But what if we designed our house and they were all prefabricated and pre-printed out and then they arrive at the site and there's no waste. Our own limber loss building is a bunch of prefabricated wooden pieces that, you know, in essence kind of clip together. So you're not wasting so much material. And if you look at Toronto, the whole of the Leslie Street spit and everything south of Front Street is all that waste that we've been using over time. Yeah, Leslie Street spit is essentially, it's kind of a peninsula into Lake Ontario. That's all the dirt that was dug up from buildings and the subway and everything in Toronto.

In fact, when you're down there, you know, and you're walking on the little beaches there, you see little pieces of concrete, bricks, rebar. Those are buildings that have been torn down, right? All of these things are new sort of frontiers for us to reimagine how we're doing things and to do it in a different way than we've done it in the past. Using the new technologies that we have, right? We'll be right back. Let's talk a little bit about building materials, Luigi, because you've been talking a lot about wood. Can we build the same types of buildings out of wood compared to steel and concrete? Like, isn't there a structural issue?

I don't know if we're building out of wood instead. Actually, wood is one of the best materials for building buildings. If it's sized to the right size with mass timber, it can perform better during fires because it chars on the outside and yet the structure is still standing. So wood is a really sound building material that we should be using more. It's also a renewable building material. So if you think of the history, say, in Japan of wooden buildings or in Norway, they have wooden buildings that are 900 years old. And so there's no reason that we can't, and Canada especially, reimagine a whole new wooden type of architecture. Now, it's not the only material we should use, and nothing is like really a silver bullet and we should just all do one thing. There are buildings that will still need to be made in concrete, but you want to build the buildings out of concrete that truly need to be made out of concrete.

But you want to do it in a more balanced way. Why did we stop using wood so much? Like, there must be a reason why we switched. So we switched early in the 20th century. We used up a lot why we switched. So we switched early in the 20th century. We used up a lot of the timber. So it became easier to use new materials that were being developed, like concrete, which lasts a long time, is fireproof, and was very cheap to form and to work. And so it kind of replaced the wooden buildings. And we wanted to build taller buildings faster, right?

And so the easiest way at that time was to work with steel and concrete. Okay. And so we've talked a lot about how to build differently now. But you also said it's better to fix the buildings that we currently have, right, to retrofit essentially. So how could we retrofit our current buildings to be more efficient? Well, there's a number of ways. There's sort of targeted incremental improvements that you can do as you're fixing up a building, like changing the windows, insulating it from the inside or outside, changing the roof, changing the energy system. But there are some really more sort of systemic approaches that we can use, which is we can reskin buildings with a double skin or with a double envelope.

Or we can actually, you know, put green roofs on all our roofs. What about windows on, you know, big, big office towers, right, with like floor to ceiling windows? How could we kind of, I guess, better use the heat that comes in or keep it out? Yeah. Well, interestingly enough, I'm sorry to use the example of Limberlost, but it's a perfect example because we designed the facades there to, you know, have about 40% glazing. But most buildings have 90% glazing or 80%. What is glazing? That's the glass on the outside of the wall.

It's the ratio of the glass to the solid pieces. And if you think of most condos, for instance, now it's almost all glass walls, right? And 40 to 50% is enough to bring the light that you need into the building so that you don't have to have a lot of lights on all the time. So if you can make facades with better insulation

and not all glass, you can reduce the energy that the buildings are consuming, right? So all of these super glass buildings are actually a problem for us. We need to rethink what is the right way to clad our office towers, our tall buildings, our condominiums, and to clad them with a better ratio of insulated to glass. So Luigi, these, I mean, these all sound like really beneficial changes, but they also sound very expensive.

And I know the report itself says it would cost $40 billion annually every year to make these changes, and 60% of that would be spent on retrofits, so fixing up the old buildings, and then the remaining $40 would go towards new builds. So this is a lot of money we're talking about. Who's going to pay for all of this? Well, you know, oddly, in the end, we're going to pay if we don't do it, right? If we don't reconstruct in a better way or build new in a better way, we'll pay it as energy costs rise and as less energy is available and as actually the climate degrades, as we've been experiencing this summer, right? Then all of a sudden things cost more.

So what you should have spent maybe at the front building something right, you end up paying two, three times over, over time. In a way, it's a false argument to say that it's too expensive because you're going to end up paying one way or another. On a practical level, though, who would actually be footing the cost? Is it going to be companies who are building the buildings or people who are buying these more energy efficient homes? Well, on a practical level, we have to start thinking of what is a way of incentivizing what are sustainable economic choices, right? I'm interested in innovation in finance and sustainable finance. Should we have new mortgages that where if you've spent on something that's more green, that actually somehow you save over time? We need to come up with interesting and new novel mechanisms.

What levers the government can use, what incentives they can provide. Business knows the experiment out east with heat pumps and the subsidy with them was successful. In other places, it hasn't been as successful. But we're going to need a lot of creativity, not only in terms of the solutions, but in terms of how do we reimagine the finances of things that makes it more feasible and possible. So essentially, this is the role of the government here then to create these kinds of incentives to encourage this kind of behavior? Absolutely. The government should be doing that. But the answers aren't only in government.

They should be in private companies as well. So mechanisms in insurance and in other instruments that we have in the society could make for a significant incentive or opportunity to provide people the opportunity to go greener. And the faster we do that, the more likely these changes are going to happen. Because honestly, like you said, if it's just going to cost more, it's going to be hard for people to do, right? So we have to figure out what is the way of covering the cost

that makes it cost less for people over time. Luigi, thank you so much for joining me today. No, thank you for the chance to talk to you about these important topics. much for joining me today. No, thank you for the chance to talk to you about these important topics. That's it for today. I'm Mainika Raman-Wellms. Our summer producer is Nagin Nia. Our producers are Madeline White, Cheryl Sutherland, and Rachel Levy-McLaughlin.

David Crosby edits the show. Adrienne Chung is our senior producer, and Angela Pachenza is our executive editor. Thanks so much for listening and I'll talk to you tomorrow.