How many units can I buildin Toronto?

Toronto homeowners can now build up to 4 units as-of-right on any residential lot — and up to 6 units in parts of Toronto and East York. But how many units can you build on your specific property?

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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, Toronto and East York areas — plus Ward 23 (Scarborough North) — gained permission for up to 6 units on eligible lots, following the City's own Zoning By-law Amendment 654-2025.

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: the City of Toronto has waived or reduced development charges for new residential units in multiplexes under certain programs. Depending on the number of units and tenure (rental vs ownership), eligible projects can avoid $200,000–$270,000 in development charges that would otherwise be payable at permit issuance.

This waiver doesn't apply automatically — it depends on the unit count, whether the units are purpose-built rental, and which program the project qualifies under. Confirm current program eligibility 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.