Sustainability and longevity go hand-in-hand with Montreal developer Maître Carré, as it completes its 189-unit rental building in Gatineau, Que. under its Mellem brand.

Maître Carré is pursuing LEED Silver certification for the project, known as Manoir-des-Trembles. It is designed with energy efficiency in mind, and includes components such as heat pumps and condensing water heaters.

“It changes our vision on construction. We need to operate on a window of 15 to 20 years,” Kevin St-Pierre, director of construction at Maître Carré, said in an interview with Sustainable Biz Canada about Mellem, the company's rental building franchise.

“It allows us to make better choices of mechanical equipment or every product to make sure it lasts and we have the opportunity for return on investment. Sometimes when you do cheap apartments or cheap condos you want to go low-budget stuff, but now that we want to keep it, we make sure to take the decision for the long-term.”

Manoir-des-Trembles represents Maître Carré’s first project with Montreal-based construction firm Pomerleau. It will become the second Mellem project to welcome tenants when it opens for move-in, which is expected to begin in October.

Looking for impact

Maître Carré was originally conceived as a condominium development, but was switched to rental housing three years ago “because we wanted to have a longer impact with the projects,” according to the company’s director of marketing Etienne Lebeau.

Pursuing energy efficiency benefits Maître Carré as a long-term owner because “that is future-proofing your building stock,” Etienne Gravel, the sustainable construction director at Pomerleau, said.

Sustainability is not new to Maître Carré. In 2022 it achieved B Corp certification, which verifies a company is meeting standards for performance, accountability and transparency in ESG categories.

Lebeau said as Maître Carré was in talks with Pomerleau, both companies realized the design for Manoir-des-Trembles was already well on the way to achieving a LEED certification.

“When were approached at first by Maître Carré to evaluate the potential for LEED certification, we checked all of the criteria and we realized it was possible to realize a LEED-certified level with the level of input they have,” Gravel said.

The Gatineau rental building was already slated to have an energy-efficient envelope and systems that reuse heat, giving it a significant head start in the LEED certification process.

How it will aim for certification

To attain the LEED Silver certification, Gravel listed off the relevant features of Manoir-des-Trembles:

• high-efficiency heat pumps;
• LED lighting;
• exhaust air heat recovery;
• low-flow plumbing fixtures;
• a high-efficiency heating coil; and
• condensing water heaters.

The result is a building that is 18.4 per cent more efficient than the 2015 National Energy Code of Canada for Buildings, and achieves a 14 per cent reduction in operational greenhouse gas emissions.

The parking lot will include 20 electric vehicle chargers upon opening and can be 100 per cent electrified, according to St-Pierre. Lebeau noted each unit will have at least two bike racks.

Gravel said Manoir-des-Trembles accommodates the transportation requirements of LEED as it is placed to “give access to a lot of different transportation modes” such as public transit, bike paths and walkability.

To address the problem of heat islands, the building will have a “green and white rooftop” that will consist of a white membrane to reflect sunlight, and maintain a substantial amount of vegetation.

The construction process for Manoir-des-Trembles aims to achieve at least a 75 per cent landfill diversion rate to meet the LEED requirements.

To embed sustainability into the building's units, Maître Carré is paying for a compost service and for its tenants to access Partage Club, an app that encourages people to share household items, Lebeau said.

Maître Carré’s portfolio

Alongside Manoir-des-Trembles in the Mellem brand are the 216-unit Ville-Marie and the 300-unit Grace Dart in Montreal. Ville-Marie is expected to be occupied this month, while Grace Dart is anticipated to be open in the spring of 2025.

The two Mellem projects are not pursuing LEED certification, Lebeau said, as Maître Carré is "in the mindset of selecting the most important criteria for each certification. There’s LEED, WELL. We didn’t want to sacrifice one thing that couldn’t count for (one) certification, but could count for another one.”

Though there is no intent to have LEED certification, sustainability is embedded into Ville-Marie. It is targeting a 25 per cent reduction in energy use.

The lessons from designing and constructing Manoir-des-Trembles will inform future Mellem projects, Lebeau added.

More Mellem projects will be announced later, according to Lebeau.