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1.9K State of Housing: Prefab, Mass Timber, and 3D Printed Housing Making Inroads in the GTA
Throughout October UrbanToronto is featuring a special State of Housing editorial series to examine the pressing housing challenges facing Toronto and the Greater Golden Horseshoe.
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Toronto’s housing pressures have accelerated interest in construction methods that can deliver homes more quickly, sustainably, and affordably than conventional approaches. Across the region, developers are turning to prefabricated systems, modular housing, and mass timber as practical alternatives, while early ventures into 3D printing point to what may follow. Companies are exploring modular manufacturing, mass timber, and more, advancing projects that compress timelines, reduce carbon footprints, and test scalable models.
Prefabricated shelter systems have emerged as one of the fastest ways to deliver deeply affordable and supportive housing. Toronto’s recent projects under the federal Rapid Housing Initiative illustrate how modular construction can shorten delivery timelines from years to months while still meeting high design and livability standards.
At the same time, the City has expanded its Modular Housing Initiative with short-term, transitional projects designed to help people move out of homelessness and toward permanent housing. Modular construction is a building method where components, such as entire suites, walls, or floors, are manufactured in a factory setting and then transported to the site for assembly. These projects are intended as temporary housing rather than long-term residences. One notable example is 1120 Ossington Avenue, designed by Smart Density for Assembly Corporation. It opened in early 2025 with 26 affordable, permanent, rent-geared-to-income homes delivered in just 17 working days, constructed using mass timber and panelized systems on a compact infill site.
Another build is underway at 185 Cummer Avenue in Willowdale: a three-storey modular building with 59 studio units designed by Montgomery Sisam Architects. Built for people experiencing and exiting homelessness, it is slated for completion in early 2026. Several other buildings of this type are being built across the city; the earliest of which was opened at 11 Macey Avenue in Scarborough in 2021.
Meanwhile, Mattamy Homes has long experimented with prefabrication, but its founder, Peter Gilgan, is now scaling the idea through Stelumar Advanced Manufacturing Inc. (SAMI). The company is building a 450,000 ft² automated facility in the GTA designed to produce up to 3,000 units a year, using robotics and AI to streamline output. Its first project, a six-storey, 47-unit residential building, is set to be completed in less than six months, a fraction of the timeline typical for comparable developments.
SAMI’s facility is also being pitched as a high-automation, data-driven production engine. The plant will build volumetric modules, wall panels, floor systems, cabinetry, and millwork, all in a controlled factory environment, and assemble as much as 80 per cent of the exterior cladding before modules leave the plant. The facility is expected to be operational in the GTA by 2026, with staffing of roughly 300 production workers across two shifts plus an office team of 75. SAMI also aims to streamline utility connections: each suite is composed of modular “boxes” that tie into centralized mechanical, electrical, and plumbing systems in the building core.
This push is mirrored by emerging Toronto startups working on prefab systems that exceed net-zero standards. Their designs incorporate advanced energy efficiency and clean-tech solutions, aligning with broader climate goals while keeping operating costs down for residents. Emerging Toronto-based cleantech firms are pushing prefab by embedding net-zero features directly into their building systems. One example is CABN, which offers homes in sizes from 540 to 2,500 ft² outfitted with FSC-certified timber, helical pile foundations (often minimizing concrete use), passive solar design, integrated solar + battery systems, and smart home controls, essentially combining renewable energy, high-performance envelopes, and prefab assembly into one package.
Elsewhere, Leader Lane Developments and Windmill Development Group are positioning themselves at the forefront of Toronto’s mass timber movement, with three projects now advancing that apply prefabricated wood systems. Hälsa at 230 Royal York Road is a nine-storey mixed-use building designed by LWPAC Architects, currently under construction as part of their Mimico Collection of three closely located sites, using off-site manufactured timber components that can cut construction time from several months to just over ten weeks.
The project is designed to achieve LEED Platinum certification with exposed timber elements, high-efficiency envelopes, and a focus on reduced embodied carbon. Once complete, Hälsa will add ground-floor community space, 58 market rental suites, and seven replacement rental units close to Mimico GO station.
Another one of their Mimico Collection sites is at 430 Royal York Road, where a nine-storey mid-rise designed by Studio JCI will continue the same focus on low-carbon, transit-accessible rental housing. Both sites are being developed to Toronto Green Standard Tier 2 and One Planet Living principles, emphasizing energy efficiency, healthy materials, and walkability.
The partners are also preparing for a big step forward across from Jane station, where BDP Quadrangle has designed a 12-storey mass timber project at 2453–2469 Bloor Street West. This building is intended to demonstrate how wood construction can compete with concrete in terms of scale and functionality in taller Avenues style buildings. By relying on lighter structural systems, the project can reduce foundation requirements and overall use of high-carbon materials. The developers see the use of engineered wood as both environmentally and financially strategic: the efficiencies, combined with the biophilic quality of exposed wood interiors, demonstrate how mass timber is evolving from boutique architecture to an economically competitive construction method in Toronto’s mid-rise market.
Industry support is growing around these ventures, aided by investments such as Element5’s manufacturing facility in St Thomas, Ontario, which supplies cross-laminated timber to the GTA. The plant is highly automated, and started producing up to 50,000m³ of CLT and glulam annually across wide-format panels (up to 3.4m wide, 15.8m long, and 380mm thick) to reduce site assembly complexity and shorten schedules. In 2025, Element5 expanded the facility, doubling its footprint from an area of roughly 137,000 ft² and to over 350,000 ft², adding a new glulam line, and increasing production capacity to 100,000m³ per year, backed by a $107 million investment and support from the HASSLACHER Group and Invest Ontario.
With prefabrication enabling faster delivery and reduced financing costs, and with growing acceptance among contractors and end-users alike, mass timber is moving from experimental to mainstream. At the same time, 3D-printed housing remains in its early stages in Toronto, but local players are beginning to test how the technology could fit into the city’s housing mix.
Firms such as Leostar Development Group and Printerra Inc. are exploring ways to adapt large-scale printers that can fabricate structural walls and components directly on-site, a process that has already demonstrated success in international markets. By reducing labour needs and speeding up assembly, 3D printing has the potential to cut construction costs and create highly customizable homes.
Despite its promise, widespread adoption of 3D printed buildings will depend on regulatory progress and building code approvals that are still in development. For now, the technology represents a glimpse of what could follow prefab and mass timber in reshaping how housing is delivered. If proven viable in the GTA, 3D printing could offer another tool for delivering affordable, resilient housing at scale.
Policy support is beginning to catch up with industry ambition, as federal initiatives like the Regional Homebuilding Innovation Initiative channel funding toward modular, mass timber, and 3D-printed housing. With $50 million committed nationally, the program is designed to help scale technologies that promise faster delivery and lower carbon footprints, creating opportunities for GTA-based developers to expand beyond pilot projects.
Alongside policy, material innovation is opening new possibilities for the future of construction. Bio-based options such as hempcrete, mycelium composites, and other renewable products are being explored in the European Union and elsewhere for their ability to reduce embodied carbon and support circular building practices. While not yet common in Toronto, these approaches hint at the next wave of sustainable housing design.
With Canada needing to nearly double housing starts to around 430,000 to 480,000 units per year until 2035 to restore affordability, the GTA is becoming a proving ground for construction methods that can deliver at scale without sacrificing sustainability. Prefabricated shelters, modular housing, mass timber projects, and early ventures into 3D printing all point to a sector in transition.
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UrbanToronto has a research service, UTPro, that provides comprehensive data on development projects in the Greater Golden Horseshoe — from proposal through to completion. We also offer Instant Reports, downloadable snapshots based on location, and a daily subscription newsletter, New Development Insider, that tracks projects from initial application. Development Insider, that tracks projects from initial application.
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Thank you to the companies joining UrbanToronto to celebrate State of Housing Month.
