David Babakaiff
Written by David Babakaiff — Co-Founder, VanPlex | 25+ Years BC Construction

Policy & Zoning | Multiplex By-law (4 units)

Toronto's City-Wide Multiplex By-law

On May 10, 2023, Toronto City Council adopted the by-law that made up to four units a permitted use on residential lots across the city. The decision came out of the Multiplex Study (2–4 units) under the EHON program. Four units fit roughly the same envelope as a detached house — and a compliant build skips rezoning entirely.

Key Takeaways

  • Up to four units as-of-right in all residential Neighbourhoods zones, city-wide.
  • Adopted May 10, 2023 (item 2023.PH3.16): OPA Law 0473, Zoning Law 0474.
  • Zoning effective May 12, 2023; Official Plan amendment effective June 14, 2023.
  • Four units fit roughly the same envelope as a detached house.

The by-law text sets the rule; the zone stamped on your parcel decides what it means for you. Apply the by-law to one lot .

The By-law at a Glance

Detail What it says
Council adoption May 10, 2023 (item 2023.PH3.16)
Official Plan amendment Law 0473 — effective June 14, 2023
Zoning By-law amendment Law 0474 — effective May 12, 2023
What it permits Up to 4 units as-of-right
Where All Neighbourhoods-designated residential lands (RD, RS, RT zones)
Building envelope Roughly the same as a detached house
Approval path Building permit — no rezoning, no Official Plan amendment, no public meeting

Dates and item numbers from the City of Toronto Multiplex Study and the by-law text in Law 0473 (PDF).

What "As-of-Right" Means Here

As-of-right means the use is already permitted by the zoning, so you do not ask the City for permission to do it — you apply for a building permit to build it. For a compliant fourplex that means no rezoning, no Official Plan amendment, and no public meeting. The four units sit inside roughly the same building envelope a detached house could occupy: the same general height, lot coverage, and setbacks for the zone.

The catch is the envelope itself. A design that exceeds the as-of-right limits on height, coverage, or setbacks needs a minor variance from the Committee of Adjustment before a permit issues. The exact figures live in Zoning By-law 569-2013.

Best For

  • A residential Neighbourhoods lot where up to four units fit the as-of-right envelope.
  • Owners who want to add density without rezoning or a public meeting.
  • New builds and conversions alike — the four-unit permission applies to both.

Usually Fails When

  • Assuming the 2023 by-law allows five or six units — it caps the city-wide permission at four.
  • A design that exceeds the envelope, where the variance timeline was not planned.
  • Treating the OPA and zoning effective dates as the same — they differ by about a month.

What To Verify Before Spending Money

  • The residential zone (RD, RS, RT) and the Neighbourhoods designation for the parcel.
  • That the proposed design fits the as-of-right envelope, or scope a variance.
  • Whether the lot is in a heritage conservation district that adds review.

Where to Go Next

Frequently Asked Questions

What does Toronto's multiplex by-law allow? +
It permits up to four dwelling units as-of-right on a residential lot in any area the Official Plan designates Neighbourhoods. Four units fit roughly the same building envelope as a detached house. Because the use is permitted, a compliant fourplex goes to a building permit with no rezoning, no Official Plan amendment, and no public meeting.
When did the multiplex by-law take effect? +
Toronto City Council adopted it on May 10, 2023 as item 2023.PH3.16. The change came in two instruments: the Zoning By-law amendment (Law 0474) took effect May 12, 2023, and the Official Plan amendment (Law 0473) took effect June 14, 2023. So the city-wide four-unit permission has been in force since spring 2023.
What are Law 0473 and Law 0474? +
They are the two by-laws Council adopted to create the multiplex permission. Law 0473 is the Official Plan Amendment and Law 0474 is the Zoning By-law Amendment. Together they amended the planning framework so that up to four units became a permitted use in residential Neighbourhoods zones across Toronto.
Does the multiplex by-law cover sixplexes? +
No. The 2023 by-law caps the city-wide permission at four units. Sixplexes (five or six units) came later, in June 2025, under a separate set of amendments (OPA 818 and By-law 654-2025) that apply as-of-right in only nine wards, with an opt-in path for the rest. City-wide means four; six is the nine-ward expansion.
Which zones does the multiplex by-law apply to? +
It applies to residential lands the Official Plan designates Neighbourhoods — the RD, RS, and RT zones cover most of these lots. That captures the large majority of Toronto's low-rise residential land. The exact zone for a parcel should be confirmed in Zoning By-law 569-2013 before designing.
How does this relate to the provincial three-unit rule? +
Ontario's Bill 23 set a floor of up to three units as-of-right on serviced residential lots. Toronto exceeded that floor with its own by-law, going to four units city-wide. So the provincial law is the backstop and Toronto's multiplex by-law is the higher local permission a city builder actually works from.

Official Sources Referenced

General information, not legal advice. Zoning and permitting rules are set by each municipality and change over time. Verify current requirements directly with the municipal Planning Department before making a decision.

Related reading

Longer pieces on the same question.

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