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?

Searching an address requires no account and stores nothing. Create a free account to save properties to your profile.

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: 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 at permit issuance.

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.