Rayside Labossière architectes
Montreal, Québec

Rayside Labossière: Existing LEED building shines with new Zero Carbon Building - Performance certification

In 2005, Rayside Labossière Architects designed the building they have since called home. The mixed-use, urban infill project is located on Ontario Street, a commercial artery of Montreal. At the time it was built, the project was among the first small-scale, private buildings to be Leadership in Energy and Environmental Design (LEED) certified in Canada.

The Rayside Labossière team saw this as a model project in 2005 —an opportunity to create an innovative building that complemented the firm’s social principles. As such, the building was an early adopter of geothermal energy and featured several water-saving measures not yet common in the market. It also featured one of the first rooftop vegetable gardens in the city. It’s no surprise that the firm is now setting another example for innovation by leveraging that original LEED investment to obtain Zero Carbon Building certification for the building’s performance in 2019.

As a made-in-Canada solution to achieving climate change commitments, the Zero Carbon Building Standard (ZCB) provides a path for both new and existing buildings to reach zero carbon. It’s a standard that fits well with Rayside Labossière’s own mission: to design architecture that is committed, sustainable, original, and pertinent.

Zero Carbon Building - Performance puts spotlight on 15-year-old design process

Rayside Labossière occupies the double-height ground floor, open mezzanine, basement and second floor, while the third floor houses two energy-efficient rental apartments.

While the building was designed with LEED certification as a specific goal in 2005, the ZCB certification was another set of criteria that the team found extremely relevant to the discussion of sustainability.

As an older LEED-certified project, Rayside Labossière was curious to see whether the strategies for reduced energy use, improved thermal performance, and responsible material use they selected in 2005 would still be effective enough to attain a ZCB – Performance certification. Since the building’s completion, the team has seen the energy-reduction benefits of their green design strategies and wanted to delve deeper into the carbon footprint of the building’s construction and operation.

For Rayside Labossière, this wasn’t just idle curiosity, but would provide valuable knowledge that could improve the design of future client projects.

Smart decisions pay off for zero carbon performance

Though the building’s construction predates the ZCB standard by a decade or so, the building was seemingly conceived in almost perfect harmony with it. The main ecological objectives of the building were, among others, the significant reduction of energy consumption, the responsible management of water and the use of materials with smaller environmental footprints.

The project has no combustion systems, and the requirement for off-site hydroelectric electricity for heating and cooling is reduced by almost half due to the building’s geothermal system in conjunction with a high-performance envelope. While the geothermal system isn’t considered an on-site source of renewable energy for the ZCB standard, it makes a significant impact on energy consumption, and Rayside Labossière plans to use it again in their upcoming office expansion.

The distribution of heat is ensured by a ventilation system with air exchanger. In addition, the building was built with exterior walls, windows, and a roof that provide great thermal insulation. Triple-glazed windows provide better thermal performance as well as an increase in the temperature of the inner pane, which increases comfort. Along with low-energy lighting, these different elements make it possible to achieve a total reduction of at least 50 per cent of energy consumption.

With respect to responsible water management, all plumbing systems included low-flow aerator nozzles to reduce water consumption, dual-flush toilets, and the office was equipped with a waterless urinal. Though these elements are more commonplace now, they were much harder to source in 2005– before the EPA even published the WaterSense program. The green roof allows for a further reduction in rainwater discharges. Today, the roof continues to be productive and includes a thriving beehive.

From an embodied carbon perspective, Rayside Labossière took care during the initial project to focus on the responsible use of building materials, relying on recycled materials as well as local and easily renewable materials. For example, kitchen cabinets, moldings and furniture are made from straw panels, while hardwood floors came from certified forests.

The many benefits of zero carbon

Rayside Labossière prides itself on its dedication to sustainable design and constantly seeks to keep abreast of current best-practices. For the firm, certifications help direct internal knowledge-gathering, while the results serve as an independent validation that the strategies they employ deliver quantifiable results.

A key selling feature of the ZCB-Design certification is that it is not only technologically feasible but also financially viable. Even in 2005, the cost premium for Rayside Labossière’s project was approximately 10 per cent more than standard construction and within approximately 10 years they have seen a simple payback from decreased operating costs. More important to the firm was the knowledge that they were building in a sustainable way that minimizes the impact of the project throughout its life—and improves the lives of the people living and working in the building.

For Rayside Labossière, achieving the ZCB – Performance certification confirms the success of the original design and the attention to ongoing operations. It affirms their commitment to addressing climate change and demonstrates the firm’s capacity to design sustainable projects even with modest budgets. It gives them first-hand experience with the ZCB – Performance standard, which is of growing interest to their clients. Most significantly, the positive experience on this certification has motivated them to pursue both ZCB-Design and ZCB-Performance certification for their new office expansion.