The Path To Carbon Neutral

By Tracy Hanes

Mapping out the difficult but rewarding road to sustainability

Canada’s carbon-reduced future is a mere half-dozen years away, with significant changes and challenges looming for Ontario’s building industry. According to the Canada Green Building Council (CaGBC), residential, commercial and construction buildings account for 17% of the country’s greenhouse gas (GHG) emissions. If you factor in building materials and construction, that number climbs to almost 30%, making the building industry Canada’s third-highest carbon emitter. 

Low-carbon construction is expected to play a major role in helping Canada achieve its carbon-reduction goals. The target is a 40-45% reduction below 2005 levels by 2030, and net-zero emissions by 2050. 

While many Ontario builders have adapted their housing products to be energy efficient, reducing carbon is more complicated, requiring more knowledge, new products and skills.

“At the heart of it, it’s an engineering problem, a financial problem, a materials problem, a construction management problem,” says Adam Molson, Daniels vice-president of rental communities and sustainability. “We basically need to change the way we build, design and finance buildings. It’s a pretty massive transformation.” 

It requires looking at operational carbon—that which is used during the operation of buildings and its infrastructure, such as heating, cooling, hot water and lighting—as well as embodied carbon, which is emitted from processes, materials or products used to build, maintain, repair, refurbish and demolish buildings. 

High-rise developments emit far more carbon than low-rise, mainly due to the required quantities of concrete and rebar. Cement, a key ingredient in concrete, is the world’s second-largest industrial CO2 emitter and is responsible for about 7% of carbon emissions globally and 1.4% in Canada. 

Ryan Zizzo, a professional engineer, is the founder and CEO of Mantle Developments, which offers consulting on climate-smart and net-zero carbon construction. Zizzo lent his expertise to updating Toronto Green Standard (TGS) V4 and is an expert volunteer committee member for CaGBC’s Low Carbon Training Program. He says builders typically look at operational carbon, which can be reduced through means such as solar photovoltaic systems, buying from the grid, or electric or geo-exchange/geothermal heating and cooling systems.

“What’s not on people’s radar is embodied carbon—how it’s made and where it’s transported from,” Zizzo notes. “That’s more difficult.” 

“Embodied carbon is the sleeping giant the industry has just woken up to,” says Molson. “It’s very different in order of magnitude and complexity than straight energy efficiency.” An energy-efficient building could have significantly more embodied carbon than an electrically powered building that isn’t as energy efficient, Molson explains. 

Zizzo says reducing carbon requires changing how the industry designs and builds. For instance, eliminating basements or underground parking garages, which use a great deal of concrete, would effectively reduce a substantial amount of embodied carbon. Builders can also look at alternative building materials such as mass timber and/or materials from agricultural byproducts such as corn husks. 

Leading Man

Some Ontario builders are already working on their low-carbon futures. Mattamy Homes is one of the companies taking the lead, and the chairman and CEO of Mattamy Asset Management Inc. Peter Gilgan has stepped into the company’s first Chief Sustainability Officer role. He felt it was important to set the tone from the top down to signal the importance of climate change and reducing emissions to Mattamy employees.

Mattamy Homes has 15 divisions across North America, each with a sustainability office. Gilgan and four team members held workshops in every division in 2022 and 2023 to discuss the importance of sustainability, affirm the goal to establish Mattamy as an industry leader in fighting climate change and identify challenges and opportunities. Gilgan also aims to help others in the industry with their carbon-reduction strategies. 

“Our intent is to prove to our peers what can be affordably done. We are trying to find solutions everyone can afford to adopt so that our industry can make a difference. We want to be very public about this and share our findings and challenges with other builders,” says Gilgan, whose company hosted a conference in late February to share its insights with others in the industry. 

The path typically begins with setting a baseline for GHG emissions and energy consumption. Mattamy used industry-accepted modelling tools to evaluate the energy and carbon impacts of 50 low-rise homes and four mid- and high-rise projects. The low-rise home assessments were completed across Canadian and U.S. markets to understand the operational and embodied carbon impacts from factors such as climate, building materials, local electrical grid emissions and energy usage. 

Daniels’ first step was to develop a clear focus and strategy. ’Sustainability’ is a catch-all term and can have many different aspects, says Molson, and with LEED criteria or TSG, “it is actually 30 things, and low carbon is one box. Trying to satisfy all 30 things took away a lot of focus. We were trying to do so much and not prioritizing what’s important.”

Crunching The Numbers On Carbon

Daniels determined that carbon and climate change was the most critical concern. Next came establishing a baseline, which can be tricky, as municipal, provincial and federal standards are measured and modelled very differently.  

“There was no apples-to-apples data,” said Molson. “We developed an internal standardized approach that allows us to unlock solutions. We have to speak the same language on every project. All the different lenses and languages are still a fundamental issue for the industry to move forward.”

Daniels examined the carbon emissions of five of its high-rise buildings, with locations in Mississauga, Brampton, Toronto and Vaughan. Two targeted LEED certification and one targeted TGS Version 3 Tier 2. Three were mixed-use, while two were rentals. Daniels used TGS Version 3 methodology for the energy models. Three projects had a Lifecycle Assessment (LCA) to report on upfront emissions using the CaGBC’s ZCB Design Standard methodology, and all buildings had the same or similar materials and structural makeup. 

The project at one end of the range emitted 3.5 times more carbon than the one at the other end. That was a light-bulb moment, says Molson. “We knew there’d be some variance but didn’t expect that much.” The highest-emitting building was in a municipality that didn’t require any standards above the Ontario Building Code, and Daniels’ partner on that project didn’t care to exceed that. The best-performing building was in Brampton, a city with a program promoting green building, with a development partner who had a keen interest in sustainability. 

“The project went through Enbridge’s Savings by Design program, and through that, we did a feasibility study on geothermal,” says Molson. “That hadn’t really been on our radar, but having that group of professionals and analysis showed us there is a positive business case, and it makes dramatic improvements in carbon emissions.” 

Based on its evaluation of the five buildings, Daniels’ baseline carbon intensity was 1,660 kg CO2 /m2—the equivalent of stacking almost four barrels of crude oil on each square metre of floor space in its communities. Upfront emissions accounted for 385 kg CO2/m2 (with concrete and rebar the highest emitters), while operating emissions were 1,275 (heating, cooling, hot water, etc.). 

All Daniels communities starting development in 2026 will target Near-Zero Whole Life Carbon. The Generation 1 commitment (2021 to 2025) of 1,000 kg k CO2/m2 will represent a 40% reduction from its baseline, and the Generation 2 target (2026 to 2030) of 600 kg CO2e/m2 is near-zero, a 64% reduction from its baseline. 

The electrification of homes will play a crucial part in achieving low- or zero-carbon levels. Mattamy has developed one all-electric townhouse community in Pickering, with another under construction in Ontario. These communities use geothermal heating and cooling and air-sourced heat pump water heaters for domestic hot water. Gilgan says hybrid solutions will be required in some locations, such as Ottawa, where temperatures get too cold for heat pumps to operate effectively in frigid weather, necessitating a natural gas backup.

Not just big builders are looking for low-carbon solutions. Mike Manning, president of Greenbilt Homes, recently built a small multi-residential building in Toronto called the FlexPlex (named for its ability to ‘flex’ from duplex to triplex to fourplex) that uses no fossil fuels. It is currently configured as a duplex, with Manning and his wife occupying the two bottom floors and a tenant family in the top unit. Manning, a certified Passive House builder, incorporated some Passive House elements, such as high levels of insulation, a carefully installed air barrier for airtightness, Passive House-rated doors and windows, and also optimized placement and sizing of windows on south- and west-facing walls. Cold-climate air-source heat pumps supply heating, cooling and water heating, with a heat recovery ventilator also installed. Due to the superior insulation, the undersized mechanical system draws less electricity. Last fall, the first monthly hydro bill for the 3,900 sq. ft. building was $205, including HST. Manning intends to install solar panels to make it a full Net Zero Carbon and Energy building. Its construction, Manning assures, cost no more per square foot than a conventional custom home. 

Tailor-Made Solutions

Architecture firm BDP Quadrangle has started to execute embodied carbon studies on its projects, in alignment with TGS voluntary measures. The lack of requirements to design low-carbon buildings, or targets for operational or embodied carbon, also makes it challenging for architects, says Michelle Xuereb, Director of Innovation at BDP Quadrangle. That requires her firm to create tailor-made, low-carbon solutions for each client.

Xuereb says the immediate capital costs of a low-carbon building can be higher than a code-compliant one. In contrast, the long-term operational costs can be significantly lower and can ensure that the value of the building remains high in the long run. If a developer builds to sell rather than to own in the long term, there may be less incentive to adopt low-carbon principles.

BDP Quadrangle begins the process with a strategy meeting to determine client goals and will look at the opportunities and constraints of the site. They discuss where the market is going regarding low-carbon, what the build is, how the client can stay competitive, mandatory requirements such as green standards, and if financial incentives are available. 

Zizzo says moving the building industry towards low-carbon or zero-carbon first requires policy encouraging it. “Some leading municipalities are doing that now, including Toronto, Caledon and Markham. Policy is a big lever.”

Zizzo says consumer demand will also push low-carbon solutions, and while many consumers look for energy efficiency and other sustainable features, carbon isn’t yet on their radar. There are labels, such as the Canada Green Building Council’s Zero Carbon Building Standard, to certify and label low-carbon buildings, but more marketing and education are needed to build awareness about such labels.

On the builder side, more training and content about low- and zero-carbon construction is required, says Zizzo, starting in school curriculums and professional training programs. He says turnout was low for the first free low-carbon training program (lowcarbontraining.ca) offered by CaGBC and other partners in late 2023, and to be effective, those programs require extensive reach. The program continues to be offered (as of this issue’s deadline) with various courses, from a general introduction to those aimed at specific groups, such as trades, architects and engineers. 

Builders can also start by hiring an expert to guide them on the low-carbon path or to look at existing resources, Zizzo recommends. For instance, the free global organization Carbon Leadership Forum (carbonleadershipforum.org) and Builders for Climate Action (buildersforclimateaction.org) have online resources and a calculator to determine the carbon footprint of building materials.

“The biggest myth is that low-carbon solutions cost more, which is not necessarily the case,” Zizzo says. A good example is the Vaughan Metropolitan Centre YMCA, where mass timber used for the aquatics centre’s ceiling was less expensive than concrete, says Zizzo. 

“Mass timber is a maturing industry in Ontario,” says Xuereb. In 2015, Ontario’s code changed to permit mass timber up to six storeys, and the BDP Quadrangle-designed 80 Atlantic for Hullmark Developments was the first timber office building built in Toronto under the new code. In July 2022, the code was revised to permit encapsulated mass timber up to 12 storeys. 

“This means we will start to see more mass timber up to this height for residential uses,” says Xuereb. “We are working on a mass timber project right now with Leader Lane Developments and Windmill Developments at Jane and Bloor.” 

Less can also be more when it comes to material choices, Zizzo explains. Finishes such as ceiling tiles and carpets could be eliminated from commercial buildings and perhaps residential buildings. “Do we need those carpets or tiles? We could only use materials we need.”

Molson says technical solutions are two-fold: using less carbon-emitting energy, switching to geo-exchange, using electricity and stopping the burning of natural gas. The other component is to use less energy by building better-performing buildings and building envelopes.

“Our whole (high-rise) industry is built around building glass towers, and they are terrible for that,” says Molson. “We need to re-engineer the building envelope, which is much more complex than switching to geothermal. How we clad buildings impacts how quickly we build. And especially with higher interest rates, that’s a challenge. The way the supply chain is set up is very complex.”

Read The Label

Early adopters such as Mattamy, Daniels and BDP Quadrangle look for products with Environmental Product Declarations (EPDs)—assessments based on verified data about the long-term environmental performance and impact of products and materials. But they aren’t always easy to source. Mattamy’s GTA Urban Division has begun collaborating with supply-chain partners to build an internal catalogue of EPDs to help understand the range of embodied carbon options available in the supply chain. 

Gilgan says different geographical areas require different materials and approaches due to labour situations, regulations, material availability or the climate. For example, low-emitting concrete can be produced by adding fly ash (residue made from pulverized coal combustion), but that only works if the fly ash is not transported long distances. And solar and wind power make more sense in Alberta than in Ontario, as there are more hours of sunlight and wind in the west. 

Gilgan said that in some cases, Mattamy has actually saved money by adopting higher environmental standards. For instance, due to the compact nature of high-rise buildings and the multiplicity of users, geothermal heating can be very efficient. “There’s a perception this is going to cost more, but we are not going to promote solutions that are going to back up business,” Gilgan says. “There have to be offsets. We have to find ways to do it that are affordable. That doesn’t mean you aren’t going to do it.”

“I think, ultimately, it will be a combination of government regulation and institutional capital,” says Molson. “To me, the huge unleveraged opportunity is the financing side. For those five projects we used for our benchmark, we got the same terms from the banks on all projects at the same interest rates. We need to work together to have financing tied to carbon performance. We need to work through OFSI (the Office of the Superintendent of Financial Institutions) to push the banks on this.”

But the biggest challenge is determining how to change buildings in a feasible way, Molson says. While green standards such as TGS have effectively pushed sustainability and low-carbon forward, his concern is “how we’re going to get there if people complain it’s too expensive, and we start back-sliding.”

“There is no question we need more participation from government regulatory bodies to reduce the impediments and provide some sort of support,” echoes Gilgan. “When electric cars got going, there were subsidies for them, and we’re going to need something like that to implement this. The worst thing we can do is exacerbate the monumental challenge of affordability.