How many unitscan I build in Toronto?
Up to 4 units as-of-right on any residential lot — up to 6 in the Sixplex Overlay (Toronto & East York + Ward 23). Enter your address to see what's buildable on yours.
Free property check · No account required · Based on Toronto zoning data
Multiplex Toronto — What the Rules Actually Allow
A multiplex is a residential building with 2 to 6 self-contained units, all within one structure that reads as a house from the street. Think duplex, triplex, fourplex, fiveplex, or sixplex. Since 2023, Toronto's zoning by-law has allowed these as-of-right across nearly all residential zones — no rezoning application required.
As-of-right means the permission already exists in the by-law. You still need a building permit and your design needs to comply with setbacks, height limits, lot coverage, and the Ontario Building Code — but you skip the planning approval process that used to take years for anything above a duplex.
Fourplex, Fiveplex, Sixplex — What's Permitted Where
Toronto expanded multiplex permissions in stages. Since May 2023, up to 4 units (a fourplex) are permitted as-of-right on any residential lot city-wide under the Province's Bill 23 framework. In June 2025, City Council enacted the Sixplex Overlay (Zoning By-law 654-2025) — up to 6 units, but only for a detached houseplex, and only within the Toronto and East York Community Council area plus Ward 23 (Scarborough North).
The Sixplex Overlay is a separate initiative from Major Street development — it's decided by location and building form (a detached house, not a semi-detached or townhouse), not by street frontage. Outside the overlay, or for a semi-detached or townhouse building, 4 units generally remains the as-of-right ceiling.
Whether you can actually build 4, 5, or 6 units depends on your lot. The permission sets a ceiling; your lot's FSI (floor space index), lot coverage limit, height limit, and setbacks set the floor. Plenty of Toronto lots can accommodate a fourplex envelope on paper but struggle to fit 4 liveable units once circulation, OBC egress, and suite sizing are factored in.
Development Charge Waivers — Up to $270,000 in Savings
One of the most significant financial changes for multiplex projects: as of 2025 the City of Toronto exempts development charges on the 2nd through 6th units in developments of up to six units. Since a Toronto residential unit would otherwise carry roughly $50,000 in charges, a full six-unit multiplex can avoid on the order of $200,000–$270,000 that would otherwise be payable. As of November 3, 2025, non-rental residential development charges in Toronto are due at occupancy rather than at permit issuance, which changes the project's cash-flow timing even before the exemption is applied.
The exemption scales with unit count, and affordable or purpose-built rental projects can qualify for further relief through City programs. Rates and program rules change, so confirm the current numbers with a planning consultant or the City's development charges office before budgeting.
FSI and Lot Coverage — Why the Number of Units Varies by Lot
The rules set the maximum. Your lot determines the practical limit. Two identical-looking properties on the same street can support very different unit counts depending on lot depth, width, existing structures, and grade. That's why address-level analysis matters.
Four gates between you
and a multiplex path.
The project flow asks whether you are testing 2, 3, 4, 5, or 6 units so the report can match the right path.
Unit Target
A conversion has a different risk profile than a full rebuild, especially when existing storeys and structure are involved.
Keep or Rebuild
Setbacks, lot coverage, height, angular planes, and frontage shape the actual low-rise envelope.
Buildable Massing
Toronto & East York and Ward 23 (Scarborough North) lots may qualify for a detached 5-6 unit houseplex under the Sixplex Overlay — zoning and envelope still decide the practical yield.
5-6 Unit Potential
As-of-right does not mean automatic.
Toronto's multiplex permissions open the door, but four things still decide whether the project is practical:
LotMore guides you
from address to blueprint.
Look up your lot
Zoning, lot dimensions, and property history — pulled from the City's public records.
Check the constraints
Setbacks, height, coverage, trees, and Sixplex Overlay eligibility all shape what's actually buildable.
See your buildable envelope
A 3D read of what can physically fit on your lot, before you spend on drawings.
Bring it to a professional
An architect or licensed designer turns a feasible envelope into drawings prepared for permit submission — LotMore's own architectural team can take it on too, from a consultation up to a full approval package.
What you can take away for your unit target.
Multiplex projects in Toronto, plainly answered.
Pick the target.
Test the envelope.
Start with the address. The analysis opens with the multiplex path ready, then your report.
No account needed to start