Marianne Touchie and Helen Stopps have spent a lot of time thinking about thermostats.
“Between Helen and I, I don’t know — hundreds and hundreds and hundreds of hours: it’s hard to put a number on it,” laughs Touchie, an assistant professor in the University of Toronto’s Department of Civil and Mineral Engineering.
The tiny household devices play an outsize role in the research that Touchie and Stopps, a PhD student, are conducting. The duo wants to find out whether so-called smart thermostats could meaningfully reduce energy consumption in Toronto’s high-rise condo towers, which experts suggest has gone largely unchecked — at least until recently.
“People could build code-compliant buildings as of five years ago that were total energy hogs. It was just a fact, but things are moving in the right direction,” says Graeme Stewart, a principal with ERA Architects, whose portfolio includes a number of deep-energy retrofits for apartment buildings across the city.
The materials used to construct many of the towers that have joined the Toronto skyline in recent decades — according to Urbanation, a Toronto-based consultancy, more than 1,000 condo buildings have gone up since 2000 — are partly to blame. “When you think about it from a building-physics perspective, the windows are really the weakest part of the building envelope,” Touchie explains. “They have the least amount of thermal resistance, so they allow the most heat to transfer across those elements. They also allow radiation to come in more readily — or impact the interior temperatures more readily — than an opaque section, obviously,” Touchie adds.
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And that’s a problem when most of a building’s facade is made of glass.
Stewart notes that the Toronto Green Standard, a set of city-enforced sustainable-design requirements, in effect discourages wall-to-wall glass towers. “The easiest way to become compliant for the Toronto Green Standards and meet those objectives is just to have smaller windows and more insulated wall surface and all that stuff,” he explains.
But the standard, which was introduced in 2006 on a voluntary basis and has since become mandatory — and increasingly rigorous — doesn’t apply to existing structures; it’s applied only when a development application works its way through the municipal-approval process. “It is a shame that these now-enforced, more stringent requirements were not enforced 20 years ago,” Stewart says. “We just built hundreds and hundreds of buildings that didn’t meet the standard.”
According to the city, the heating and cooling of buildings is responsible for 52 per cent of Toronto’s greenhouse-gas emissions. So, as the city works to reduce its carbon footprint through initiatives such as the Green Standard, staff are turning their attention to the glass condo towers that are already here. “That’s something that a lot of us, including we at the city and the industry, are just kind of diving into now,” says Rae-Anne Miller, manager of public energy initiatives for the city’s environment and energy division.
Through TransformTO, a municipal climate strategy, the city is researching the matter and digging into what kind of retroactive action can be taken. “One of the really interesting parts of TransformTO is looking at what kind of authority does the City of Toronto have,” Miller says.
But getting meaningful data about the energy efficiency of Toronto’s existing condo towers can be a struggle. Miller is hopeful that provincial regulations that took effect last year will provide useful insights: as of this year, buildings 100,000 square feet and higher are required to report electricity, water, and gas use. But these numbers show only a building’s total energy consumption — they don’t go down to the suite level. “Yeah, there’s challenges there,” Miller admits.
Touchie and Stopps have also come up against the data gap — and that’s where their research comes in. As part of their study, smart thermostats were installed in 56 units in two recently completed, heavily glazed Toronto condo buildings (Touchie didn’t want to identify which ones, as, she says, “the results can potentially impact people’s property value”). The year-long study, which wrapped up this fall, found that hourly HVAC (heating, ventilation, and air-conditioning) system run times were reduced by an average of 17 per cent.
The two are now looking at what the implications would be for the buildings’ central cooling and heating systems, which have ranges in which they perform most efficiently. It is possible, for example, that changes to in-suite utility use could push these systems outside these zones, making the exercise counterproductive. They expect to have results within nine months. Until then, Touchie is reluctant to estimate to what degree smart thermostats could reduce energy use in a condo tower. But she expects it “is not insignificant,” adding, “It seems so silly to be building these buildings with these non-programmable thermostats.”
Other examples of retrofits that can improve a building’s performance are switching to a high-efficiency boiler for heating water, installing energy-efficient windows or otherwise renovating a building envelope, and automating the heating and cooling systems for shared spaces, such as hallways and amenity areas.
While a number of the city’s aging rental-apartment buildings have seen such upgrades, the condo segment has lagged. One explanation for that is timing. Dana Senagama, Canada Mortgage and Housing Corporation’s principal market analyst for the GTA, estimates that 80 per cent of the apartment buildings in the Toronto census metropolitan area were constructed before 1990 — many date back to the ’60s and ’70s. The first condo boom didn’t peak until 1989, she notes, adding, “The condos became a phenomenon really in the last 20 years.” Therefore, they “wouldn’t need the same kind of retrofitting” as rental buildings, she says.
But there is another factor at play, Touchie suggests. While it might be in the interest of a rental-building owner to reduce operating costs through green retrofits, condo developers don’t have the same vested interests. They are selling units and have no future stake in the project. “There’s no incentive to design buildings that are going to last and that are going to perform well over the life of the building, because it’s a lot more expensive from a capital-cost perspective when you’re doing this initial construction,” says Touchie. “I feel like we almost need to change the model that we use to build these buildings.”
Touchie points to Seattle, where developers can be penalized if their buildings don’t meet specific green standards. The City of Seattle confirms that it has programs in place through which penalties can be retroactively levied against developers. “However, these are not mandatory programs,” a city spokesperson tells TVO.org by email. Rather, in exchange for agreeing to meet higher standards — and to avoid facing financial penalties if a building fails testing about a year after completion — developers can receive incentives such as greater density for a building site and a faster permitting process.
Stewart emphasizes the importance of regulation: “The building code is king, and the more stringent the code, that’s how you get outcomes,” he says. “Obviously, positive incentives like funding and grants and stuff really help — and, certainly, they’re a part of the ecosystem — but just standards really push the market.”