1120 Ossington | mcCallumSather | Media - Sustainability

Efficient

The project was developed around a highly prefabricated construction strategy. The primary structure uses three-ply cross-laminated timber (CLT) panels supplied by Element5, reducing reliance on conventional concrete and steel for the above-ground structure. Internal timber-framed partitions were also prefabricated, while the exterior enclosure incorporated pre-clad panels, including cladding installed in advance at the blindside walls to suit the constraints of the narrow infill site.
The foundation uses the Legalett insulated slab and foundation system, providing a frost-protected foundation solution suited to the site and accelerated construction programme.
Prefabrication was particularly valuable on the constrained urban site. The CLT structure and enclosure were erected in approximately 17 days, reducing construction time and disruption to the surrounding neighbourhood. Moving much of the fabrication into controlled factory conditions also reduced the cutting, fitting, and rework required on site, helping to minimise material waste. Prefabrication of the internal partitions and enclosure allowed components to be coordinated before delivery.
A whole-building life-cycle assessment or verified project-specific embodied carbon calculation was not completed. However, the material and construction strategy reduced site activity, construction duration, and material waste compared with a conventional construction process.

Efficient

The project was designed to exceed the energy performance requirements established through the Canada Mortgage and Housing Corporation’s (CMHC) Rapid Housing Initiative. It combines an R-40 nominal building envelope with a Passive House-rated slab assembly and mechanical systems intended to reduce operational energy use.
Energy modelling indicates performance approximately 40 percent better than the National Energy Code for Buildings (NECB) baseline. A building automation system monitors energy demand and overall energy use during operation against Thermal Energy Demand Intensity (TEDI) and Total Energy Use Intensity (TEUI) targets.
CMHC performance and sustainability requirements also informed material and building system decisions throughout the project.

As permanent supportive housing, durability, accessibility, and ease of maintenance were important considerations throughout the design. Materials and assemblies were selected to withstand continuous residential use while remaining practical to maintain and replace over time.

Adaptive Reuse and Flexible Design Considerations

Prefabrication provided greater consistency and quality control during manufacture, while the straightforward structural organisation and durable primary structure support long-term adaptability.

Sustainability Report