The future of urban living is clean — and affordable
Increasing access to affordable housing in urban markets and improving environmental sustainability are not usually part of the same conversation, but the subjects are in fact closely linked.
The construction and operation of buildings are responsible for roughly 30% of our greenhouse gas emissions, according to one estimate. The number is even higher in densely populated regions such as the Greater Toronto Area, where buildings generate as much as 45% of carbon that’s released into the atmosphere. There are costs attached to those numbers, and invariably they are passed along to consumers.
At the same time, there is a need for housing solutions that address scarcity of supply by means other than suburban sprawl or urban high-rise construction.
Through innovative research and ambitious pilot projects, Ryerson is at the forefront of finding ways to address those concerns.
30%of our greenhouse gas emissions can be attributed to the construction and operation of buildings
Home, sweet alternative home
Location, location, location. This mantra of the real estate industry persists, but it’s no longer the leading factor in determining the appeal of a residential property. Canadians who are demanding action to address climate change are also looking to their homes to provide part of the solution. And, price is still very much part of the equation for buyers and renters.
But increasingly, such considerations can lead to unwelcome trade-offs. A lower-priced, comfortable home built to contemporary standards in the suburbs? Newer but more expensive in-fill or a high-rise apartment or condominium in the city?
For architect and researcher Cheryl Atkinson, another viable option strikes a balance between the desire for urban living, a low carbon footprint and affordability: housing that uses eco-friendly materials and building processes along with net-zero design targets in carbon emissions, energy use, toxic construction materials, landfill waste and cost premium compared with homes built using traditional supplies and methods.
ZeroHouse, a partnership between Ryerson’s Architectural Science Department and the Endeavour Centre, is novel not just for its design but also the team behind it. In addition to Atkinson, professor of engineering Alan Fung and professor of entrepreneurship and strategy Philip Walsh collaborated on this solution to address sustainable urban housing.
The project tapped into a growing opportunity for what’s referred to as missing-middle housing: duplexes, stacked row units and bungalow courts that sit in the middle of a spectrum between detached single-family homes and mid- to high-rise apartment or condominium towers.
Moreover, they’re intended to be built on land formerly occupied by low-density structures — one storey storage buildings and auto body shops , for example — the neglected spaces in existing urban neighbourhoods.
4Number of weeks required for on-site construction of ZeroHouse
“There are lots of under-utilized sites for adding mid-rise density within existing urban footprints, if we were more clever about it,” says Atkinson.
“While this project was designed as urban infill for busy arterial areas that border existing low-rise neighbourhoods in Toronto, the same construction strategies could be scaled up or down in a variety of locales in other cities.”
The beauty and benefits of green building
Although only a single unit was built, the ZeroHouse prototype was conceived as the upper unit of a stacked townhouse with ground-floor commercial space that could exist as part of a mid-density urban development.
“It was also really important to me as a designer to integrate beauty into the mix,” Atkinson explains. “Elegant and beautiful mid-rise housing is the urban fabric of our great global cities. Housing should be worthy of design attention.”
Indeed, the 1,100-square-foot, wood-framed structure features clean minimalist lines and details both inside and out. Birch ply interior finishes and flooring made with recycled ash provide a soothing ambience within the airtight and highly insulated enclosure. State-of-the-art active and passive systems, including roof-integrated photovoltaics, add to the dwelling’s futurist vibe.
As a proof-of-concept project, ZeroHouse also demonstrated the advantages of using prefabrication as a method of construction. Floor, wall and roof sections were built separately in a makeshift factory setting, reducing total construction time on site to just four weeks, compared with the 20 to 50 needed — depending on the season, materials used and site location — for conventional builds.
Only a day was needed to assemble those pieces, with pre-installed windows and doors, on a temporary foundation. Another six days were used to install prefabricated stairs and interior finishes, roofing and exterior cladding.
While this project was designed as urban infill for busy arterial areas that border existing low-rise neighbourhoods in Toronto, the same construction strategies could be scaled up or down in a variety of locales in other cities.Cherly Atkinson, Associate Professor, Architectural Science and ZeroHouse designer
Along with that efficiency, a striking outcome was how little waste was sent to a landfill as unrecyclable: just eight kilograms, contained in a few garbage bags, as opposed to 1000 times that produced with typical house construction. That’s partly a result of design and the greater degree of precision that could be achieved in a controlled factory setting for fabrication.
Both of those factors were reflected in the building’s subsequent fate. It was disassembled and reassembled several times, including for a brief stint as a showpiece exhibit outside the 2017 Expo for Design, Innovation & Technology in Toronto. It now has a private owner and is lived in permanently in southwestern Ontario, although Atkinson and her colleagues continue to monitor and study its performance while developing and promoting the concept.
“It’s still getting attention from developers, home owners and municipalities interested in changing the status quo,” Atkinson says.
In fact, scalability is fundamental to the potential ZeroHouse represents. It’s precisely the type of urban housing solution that can be exported and expanded upon across the globe. As housing prices soar in densely populated urban centres around the world, sustainable alternatives to traditional single dwelling homes are key to ensuring high livability standards and mitigating environmental impacts.