At 1120 Ossington in Toronto, speed of construction serves a long-term purpose: providing permanent homes for people leaving chronic homelessness. Completed in December 2024, the three-storey development contains 25 rent-geared-to-income apartments. mcCallumSather carried the project through technical design and construction preparation, translating an already approved building concept into a coordinated prefabricated mass timber system.
More Housing Within an Existing Urban Site
Developed by St. Clare’s Multifaith Housing Society, the building occupies surplus land beside a former church already converted into supportive housing. This relationship makes the project an exercise in intensifying an established residential site, adding homes without extending the urban footprint or requiring new infrastructure.
The design team’s starting point was unusually defined. Municipal site plan approval was already secured, with the building’s form, footprint and exterior design established. Its work therefore centred on resolving technical details, coordinating consultants and making the approved scheme buildable within a narrow infill plot. Here, architectural value emerges through careful implementation as much as through the initial concept.
Prefabricated Timber Speeds Up Assembly
The structural frame and enclosure were erected in 17 days, using three-ply cross-laminated timber panels manufactured by Element5. Made from Ontario-sourced wood and CNC-fabricated off-site, the panels arrived ready for assembly. This compressed erection period concerns the frame and enclosure, rather than the complete construction programme.
The tight site shaped the sequence of work. Crews assembled the rear portion first to accommodate crane operations, then continued towards the front. Prefabrication reduced on-site disruption, but it also shifted decisions earlier: dimensions, connections and consultant coordination needed close attention before components reached the property. The project illustrates how a fast assembly process depends on substantial preparation.
Energy Targets Beyond the Building Envelope
A high-performance envelope, Passive House-rated slab assembly and energy-conscious mechanical systems support the building’s operational strategy. The project was designed to exceed the energy requirements of the Canada Mortgage and Housing Corporation’s Rapid Housing Initiative. The slab specification should not be read as certification of the entire building to Passive House standards.
Energy modelling indicates performance approximately 40 percent better than the National Energy Code for Buildings baseline. That figure is a design-stage projection; a building automation system is intended to track key energy-use metrics after occupancy. Monitoring will provide a basis for comparing the modelled expectations with the building’s actual operation.
Private Homes With Space for Community
Each apartment includes a private bathroom and kitchenette, while shared indoor areas accommodate resident services and community programming. Even small dimensional adjustments mattered: during construction, an interior wall was modified to gain approximately three inches of kitchenette clearance, allowing the unit to meet accessibility requirements without changing its overall layout.
Outside, artist Leo Krukowski contributed integrated metal screens referencing Indigenous and naturalized plant species. These elements bring a locally rooted visual layer to the streetscape. For mcCallumSather, 1120 Ossington demonstrates how technical coordination, prefabricated timber and modest urban infill can work together to deliver permanent supportive housing, with everyday privacy and shared support built into the programme.
| Item | Details |
|---|---|
| Project | 1120 Ossington |
| Location | 1120 Ossington Avenue, Toronto, Canada |
| Developer | St. Clare’s Multifaith Housing Society |
| Technical design and coordination | mcCallumSather; appointed after site plan approval |
| Programme | 25 permanent rent-geared-to-income supportive homes |
| Storeys | 3 |
| Timber system | Three-ply CLT panels, CNC-fabricated by Element5 using Ontario-sourced wood |
| Frame and enclosure erection | 17 days |
| Modelled energy performance | Approximately 40% better than the NECB baseline |
| Energy measures | High-performance envelope, Passive House-rated slab assembly, efficient mechanical systems and building automation monitoring |
| Metal screen artist | Leo Krukowski |
| Completion | December 2024 |