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Emissions out. Ecocentric’s in.

Worker installing solar panels on roof

Season 2, Episode 1


Every year, hundreds of thousands of people move to Toronto, which means the need for housing is not slowing down, however neither is the rising costs. This leads to an increase in the construction of high rises, which are polluting the environment. The solution? The ZEROhouse concept is a 1,100-square-foot stacked townhouse designed to be built on cheap land formerly occupied by one or two-storey buildings in existing neighbourhoods.

In this episode, we chat with architectural science professor Cheryl Atkinson about her work on the project and ZeroHouse resident Kim Harris.


ZeroHouse is a fully functional, sustainable home built with zero net carbon emissions, zero energy use and zero toxic materials.

Materials used to build house:

The 1,100-square-foot, wood-framed structure is made of eco-friendly materials such as straw bale and wood fibre insulation. The floor is made from ash trees cut down due to emerald ash borer infestation and the exterior is covered in peel-and-stick materials that turn solar energy into usable electricity.


Amanda: This is The Forefront, an award winning podcast that explores ideas for cities. I’m Amanda Cupido. 

So here’s the problem: Toronto is a busy place—and every year, it gets busier. In fact, in 2019, Toronto Metropolitan University’s Centre for Urban Research and Land Development found that the Greater Toronto Area was the fastest growing metropolitan area in Canada and the US. Plus, Ontario’s Ministry of Finance believes that the population of Toronto will top 8 million within the next ten years. All of those people need somewhere to live. 

Now, anyone who’s been to Toronto knows that the city is packed with high rise buildings filled with apartments of all shapes and sizes. But what many people don't realize is that there’s an environmental impact to consider. In the GTA, housing and buildings account for 48% of our carbon footprint.

Cheryl: It's not just about the energy that we produce, when we heat and cool buildings, it's about all of the energy that goes into the materials that we use, like concrete and steel, high rise buildings have a huge embodied carbon footprint. 

Amanda: That’s Dr. Cheryl Atkinson. She’s an architect and an associate professor in the Department of Architectural Science at Toronto Metropolitan University.

Cheryl: You have to burn stone essentially, to make the Portland cement that you make concrete out of, you transport materials, huge distances, so etc, etc. So there's really a lot of embodied energy we're recognizing that's just in the construction materials themselves. 

Amanda: While on sabbatical in 2017, Cheryl began working on a project with students from Toronto Metropolitan University, U of T, and The Endeavour Centre -- which is a school in Peterborough, ON that specializes in sustainable building. Their goal was to build a prototype of a house that was carbon neutral, but still beautiful.

Cheryl: What we were trying to do was, do a demonstration home that was sustainable in a whole bunch of different ways, rather than just being about not being able to work off the grid or not consume fossil fuel energy. It was designed to be holistically energy efficient and the kind of architecture that would make people happy in their daily lives, with lots of daylight, all the good things that make architecture thrive, make people thrive in good architecture. 

Amanda: What they ended up with was an 1100 square foot, two-story townhouse called a ZeroHouse—meaning zero net carbon emissions, zero energy use, zero toxic materials, and zero cost premium over a traditional house of a similar size. This kind of house is now a home to a self-described “eco maniac.”

Kim: Well, when I was 15 years old, which is a really long time ago, I worked in a grocery store and phosphates in laundry detergent were causing a lot of problems in the Great Lakes.

Amanda: That’s Kim Harris. She says she’s been passionate about the environment for most of her life. 

Kim: And the grocery store I worked in sold one phosphate free detergent. And so every time I checked out somebody who wasn't buying it, I told them about it. And I didn't convert that many people, but I'm always doing stuff like that. I'm on the sustainability committee for the town I live in now. And I've never used, taking a plastic bag at a grocery store. I’ve never had a throw-away plastic bottle of water. I’ve just made it a mission not to consume waste.

Amanda: In 2017, Kim went to the movies with her good friend, Cheryl Atkinson -- Cheryl asked if she’d be interested in being the first person to live permanently in a ZeroHouse. Kim jumped at the chance. 

Kim: When I lived in a house in Toronto, it was quite large. And it makes me realize, when we have large houses, we tend to fill them. And when we live in a small house, we don't need so much stuff. This house is over 1000 square feet and it's just the perfect size for one or two people. And I live here by myself and I find I don't need any more space than what I have here. I just think we have a crisis in our planet right now. And I don't see as much action as I would like to see in people personally or in our governments. And that's one thing I love about this house is it inspires people to do something about climate climate crisis - I don't even like to say climate change. I like to say climate crisis, and not let anybody off the hook. 

Amanda: Okay - so people can MORALLY feel all warm and fuzzy about living in the home but can it LITERALLY keep someone warm during our good ol' Canadian winters? Here's Cheryl:

Cheryl: We stuffed the walls with straw, which is a very cheap and readily grown insulation material again, with lots of air pockets naturally incorporated into it. So half the lower half of the house, the walls are full of straw bale. And the upper half is recycled paper cellulose blown into the walls. We used also triple glazing and fiberglass windows which don't have any thermal bridging, which is they have a high insulation value in the frame of the window, better than wood actually and lower maintenance. And they're made of glass, which is an infinitely recyclable material.  So the frame is fiberglass which is made of an opaque glass and then the windows are triple glazed so they’re super energy efficient, too.

Amanda: On top of all of that, ZeroHouse uses something called integrated photovoltaics, which is a fancy way of saying solar panels. Cheryl’s team uses a special photovoltaic membrane that sticks directly onto the metal siding of the house.

Cheryl: We looked at some reports from some researchers, who’d been looking at low altitude sun in Canada and we determined that we could generate enough energy from the roof of our upper unit to run it and half of the energy needs of the unit below. But if we put...photovoltaics on the southern facade of both buildings, then we could generate enough energy for both units. So while the facade is less efficient in a place like Canada with a lot of low angle sun in the winter, you do collect a significant amount of energy. 

Amanda: But Cheryl’s interest in the project wasn’t only limited to its environmental sustainability. She also wanted to make sure that the team developed something that was urbanistically sustainable—meaning that it's also good for the city.

Cheryl: It was important to me that it was housing, it wasn't a single family home on a big lot. It's designed to be infill housing...what we build is essentially a two storey upper unit of a five storey building, which would have been two stackable houses on top of each other over retail. So the idea was it would be infilled into a site in Toronto on an existing arterial street. So we're taking advantage of existing infrastructure, not building on green field sites. Using existing transit systems, existing sewers and roads and schools and community centres and all of that. So it's recycling this existing infrastructure. I think a lot of people don't realize that despite all the growth in Toronto and the high rises, exploding and popping up everywhere, we're actually losing population in a lot of our inner city neighbourhoods, the low rise in inner city neighbourhoods. And, and suburbs, largely because of zoning regulations that don't allow for greater intensity. So you know, people age, they move out of neighbourhoods, and we're actually losing population, schools are closing in a lot of these neighbourhoods. So the idea was to reinvigorate them with this infill housing, that's mid-rise.

Amanda: Cheryl says the ZeroHouse is also SOCIALLY sustainable.

Cheryl: You know, you can walk up at either end of the building, there's a common corridor where you can bump into your friends and neighbours before you open your door. There's windows on three orientations of the building, so that you get lots of cross circulation and natural ventilation. We designed a courtyard into each unit so that you got light, not just from the south, but from the east, and, and the north and through this operable window of this common courtyard.

Amanda: Are you getting an image in your head of what this looks like? Sounds pretty beautiful doesn't it? 

Cheryl: We worked hard to really make it attractive as a building. So I think it's, if you've seen any of the images of the interior, it's quite handsome. We panelized the whole thing, we organized the patterning of the panels. It's spatially interesting, architecturally, it's got a double height space. 

Kim: Number one, it's the most beautiful house I've ever lived in. The aesthetic of this house - you have to come and visit it. It is so beautiful. I think there's so much wood there's such a good vibe here. There's no paint, there's no varnish, there's nothing toxic in this whole house. And it really means to me that change is possible—that, and we aren't sacrificing beauty.

Amanda: That’s exactly what Cheryl set out to achieve with this project: sustainability without sacrificing the aesthetic. She believes the combination of these factors is the key to a more environmentally friendly future. 

Cheryl: Ecological buildings have had a bit of a bad rap over the years, people thought that there's, you know, there's architecture, and then there's the other stuff, which worries about energy efficiency, and I think this, these two things have to come together. And I think they are, finally. People are, well, they recognize they have to buy houses, or live in buildings that are way more energy efficient, but they also want them to be beautiful and enjoyable. It's kind of like the Tesla car, you know? Taking a, you know, EV cars always used to look very, they were a bit quirky. And you would be advertising that you cared about the environment by driving one. And now somebody's made a luxury car that looks like it's any other luxury car, and it just happens to be a really well designed, energy efficient car. 

Amanda: For Kim, the biggest benefit of living in the ZeroHouse is feeling that she’s practicing what she preaches. 

Kim: One of the things it's given me is, I think, I put my money where my mouth was, do you know what I mean? I feel like that gives me a right to challenge people on their lack of action in the climate crisis.

Amanda: So, are ZeroHouses the way of the future? Maybe! Who wouldn’t want to live in a beautiful home that also happens to be good for the environment and good for the city you live in? 

Whether we all end up in ZeroHouses or not, Cheryl and her team proved an important point: prioritizing sustainability in our housing does not mean we have to give up on creating beautiful spaces. In fact, the combination of these two factors might just be the thing that gets more people on board with environmental action and urbanism. 

And the more people we get on board, the closer we get to slowing the climate crisis, building better cities, and living happier lives. Wrapping up, here’s a final word from Cheryl about Toronto Metropolitan University's role in all of this...

Cheryl: I think the collaborative spirit that this university entrenches into their core philosophy was important to making this happen. And that they're certainly advocates for experiential learning, which this was all about, as well. So I think it's a great place to try and do projects like this, and they're difficult to do. There's lots of logistical issues and, and they were always helpful and enthusiastic about making it happen. So it was great to have that relationship with our campus.

Amanda: This podcast was created for alumni and friends by University Advancement in partnership with City Building Toronto Metropolitan University. Special thanks to our guests on today’s episode: Cheryl Atkinson and Kim Harris. This podcast was created by me, Amanda Cupido and Emily Morantz. Both of us are proud Toronto Metropolitan University grads! To learn more about ZeroHouses, and more episodes of this podcast and others, visit

The Forefront — Ideas for cities

TMU’s award-winning podcast The Forefront: Ideas for cities explores the role the university is playing in creating more inclusive, sustainable and livable cities.

The Canadian Council for the Advancement of Education (CCAE) Prix d’Excellence Award medallion

The Forefront is a proud recipient of the Canadian Council for the Advancement of Education (CCAE) Prix d’Excellence Award.

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