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 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

Sixplexes & the 9 Wards

Where five or six units are allowed — and where they are not.

Bill 23 (Ontario)

The provincial three-unit floor Toronto exceeded.

How It Works

The path from a single-family lot to four homes.

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.