The City of Toronto has expanded its Pre-Approved Building Plans Program with new standardized designs for fourplex and six-plex buildings, according to Ontario Construction Report. The new plans include designs for both wide and narrow lots and build on the city's existing pre-approved plans for garden and laneway suites.
The designs are intended to give property owners a starting point for preparing building permit applications by providing building designs at no cost, the report notes. Developed specifically for Toronto neighbourhoods, the designs comply with the Ontario Building Code and incorporate provisions for features including bicycle parking, waste storage and sustainable building measures. Accessibility, climate resilience, construction cost and ease of construction were also considered in developing the designs. The architectural firm responsible for the plans was selected through a competitive procurement process.
Why glazing contractors should pay attention
The City of Toronto's official pre-approved plans page frames the program as a way to make building an additional dwelling unit faster and less expensive. "These pre-approved plans give homeowners a head start when considering missing middle housing, helping support the creation of more housing options across the city", according to the City of Toronto.
For Ontario window and door manufacturers and installers, that head start has a practical effect: less site-by-site variation. A set of city-reviewed designs that can be reused on multiple lots gives fabricators and glazing contractors a more predictable pattern of openings, sizes and performance requirements. It does not eliminate custom work, but it can reduce the number of one-off fenestration packages that slow down missing-middle projects.
Repeatability matters in a market where custom low-rise infill projects can force window suppliers to hold unusual stock, produce short-run sizes and send site crews to unfamiliar conditions. A city-reviewed fourplex plan that appears on multiple lots gives a fabricator something closer to a production run. It also lets installers focus on quality and air barrier continuity rather than discovering new opening dimensions on every site. That does not guarantee identical fenestration packages—site-specific drawings still govern—but it narrows the range of likely variation.
The city's page notes that the plans have been reviewed by City staff to ensure the building designs comply with the Ontario Building Code and the city's zoning by-law. For fenestration suppliers, the Ontario Building Code sets the performance baseline through standards such as CSA A440 and the North American Fenestration Standard, so a pre-reviewed project still carries the same window and door obligations as any other low-rise residential build in Ontario.
How the pre-approval process changes permit submissions
"When you submit a building permit application using a pre-approved plan, you do not need to submit a copy of the plan with your application", the city explains on its pre-approved plans page. Instead, an applicant chooses a building form, HVAC system and references the plan number on the submission. Because the plans have been pre-reviewed for compliance with zoning and Ontario Building Code requirements, the city does not need to review the design if it is used without modifications.
That faster review path extends only to unmodified designs. If any modifications are made to the pre-approved plan—including HVAC or plumbing changes—the plan will no longer be considered pre-approved, and the applicant must follow the normal submission instructions for the appropriate application type. The city says the homeowner or designer using the plan remains responsible for the design and should ensure the plan complies with applicable law.
For window and door suppliers, the practical effect of a pre-approved plan is not that the city hands out a fenestration specification. The pre-approval covers the building design, not the individual products. The city's page makes clear that an applicant still needs to reference the plan number and choose a building form and HVAC system, but site-specific drawings—including those that define window and door installations—remain the responsibility of the qualified design professional. A supplier should still expect to receive detailed fenestration drawings, shop drawings and installation details from that professional before quoting or releasing product.
Where the new multiplex permissions apply
According to Ontario Construction Report, fourplexes are currently permitted across Toronto, while permissions for sixplexes vary depending on the location. Where a proposed multiplex meets applicable zoning requirements, property owners can apply directly for a building permit without seeking approval from the Committee of Adjustment. The program complements the Canada Mortgage and Housing Corporation's Housing Design Catalogue and the city's expanded multiplex zoning permissions.
The expanded catalogue builds on an existing set of pre-approved plans for garden and laneway suites, which the city has already been offering. That continuity matters for glazing firms that have already worked on Toronto laneway or garden suite projects. The same sourcing patterns, code references and site conditions often carry over to fourplex and six-plex work. Firms that have learned the city's pre-approval workflow on smaller accessory dwelling units will find the multiplex path largely familiar.
The new designs can be adapted for individual properties but do not eliminate the need for professional design services. Property owners must still retain a qualified design professional to take responsibility for the project and prepare site-specific drawings and other information required for a building permit application. The multiplex plans will also be subject to the city's normal review process.
What the expansion means for Ontario fabricators
Toronto's expanded pre-approved multiplex catalogue does not change the Ontario Building Code or create a new window specification. What it changes is repetition. More fourplex and six-plex projects moving through a standardized pre-approval path means more opportunities for fabricators to quote familiar openings and for installers to build on prior site experience. The city has not published a schedule for additional designs, but the current release already covers both wide and narrow lots—the two most common conditions for infill multiplexes in the city's residential neighbourhoods.
The inclusion of sustainable building measures in the designs also signals that window and door performance will remain a key part of the permit conversation, even if the city has not set out specific energy performance thresholds in the announcement. Ontario fabricators should watch for site-specific drawings from qualified design professionals, since the pre-approved plans still require that professional oversight.
The city has not said how many property owners are expected to use the new multiplex plans, nor has it published fenestration-specific requirements beyond the Ontario Building Code compliance already referenced. For Ontario fabricators, the expansion is best read as a demand signal rather than a technical specification. As Toronto pushes more missing-middle housing through a standardized approval route, the window and door packages attached to those projects become a more regular, repeatable part of the city's residential construction mix.