On May 10, 2023, Toronto City Council adopted Official Plan and Zoning By-law amendments to permit multiplexes citywide: duplexes, triplexes and fourplexes in the residential zones of Zoning By-law 569-2013 (including the RD, RS and RT zones), with built-form standards to keep the scale consistent. The City reports the amendments are in effect, as no appeals were received.
Separately, Council adopted amendments on February 5, 2025 permitting multiplexes of up to six units in Ward 23 (Scarborough North), following an area-specific study. That permission is not citywide (as of October 16, 2026).
What "permitted" does and does not mean
- It means zoning allows the use. The building still has to meet the zoning's built-form rules (height, depth, setbacks) and the Ontario Building Code, and needs a building permit.
- Converting an existing house usually involves fire separation, egress and services work that a designer or engineer has to assess for the specific building.
- Heritage designation or a Heritage Conservation District can add approvals for exterior changes.
- New units affect property taxes and, depending on when they are first occupied, how rent rules apply.
Buying with a plan
If a house is being bought for its multiplex potential, ask for zoning and building advice on that lot before firming up. The City's Zoning By-law pages and Toronto Building's preliminary project review are the starting point. The basement flooding subsidy covers properties up to fourplexes.