If you own a house on a Toronto residential lot, you can replace it with up to four units — no rezoning, no public meeting, no councillor’s sign-off. The city-wide fourplex has been law since 2023. Most owners don’t realize how much it actually lets them build. Here’s the real envelope.
TL;DR
- Toronto’s city-wide multiplex by-law permits up to 4 units as-of-right on all lands designated Neighbourhoods — adopted by Council May 10, 2023 (OPA = Law 0473, Zoning = Law 0474).
- As-of-right means no rezoning and no public meeting for a compliant project. You apply for a building permit, not a planning approval.
- Up to four units fit roughly the same building envelope as a detached house — same setbacks, same lot coverage, same 10 m-ish height as your zone allows.
- No parking is required for a duplex, triplex or fourplex (since Feb 3, 2022).
- A laneway suite or garden suite can add a unit on top — those are separate, stackable permissions.
- Want more than four? A sixplex is only as-of-right in nine wards, not city-wide.
What “as-of-right” really means
This is the part that changes the math. On May 10, 2023, Council adopted the multiplex by-law (item 2023.PH3.16). The zoning came into effect May 12, the Official Plan amendment June 14. It applies to all Neighbourhoods-designated lands across the city — the RD, RS and RT zones that cover most of Toronto’s house neighbourhoods. The City’s multiplex study page is the source.
As-of-right means a fourplex is a use you’re already permitted. There’s no rezoning application, no Committee of Adjustment hearing, no community consultation, no neighbour able to appeal it to the OLT. If your design stays within the existing zoning rules, you submit for a building permit like any renovation. That removes the single biggest source of delay and uncertainty in low-rise development.
The envelope: about the same as a house
Here’s what surprises people. A fourplex doesn’t get a bigger building than a single detached house would. It gets the same envelope, divided into four units instead of one. Per the City’s considerations page:
- Height follows your zone’s Height Overlay. If the overlay is under 10 m, the multiplex max is 10 m.
- Lot coverage rules still apply — the same maximum footprint as any other building in your zone.
- Setbacks are the same as other residential building types in your zone (R, RD, RS, RT, RM).
- FSI (the “d” density value) does not apply to multiplexes — though site-specific Chapter 900 exceptions can still impose one.
So the design exercise is fitting four self-contained homes inside the box a house would occupy. On a typical lot, lot coverage and rear-yard setback usually decide how much you get before height ever binds.
Parking: zero required
Since February 3, 2022, a duplex, triplex or fourplex requires no parking in Toronto. Council removed most minimum parking requirements on Dec 15, 2021 (item PH29.3); the change took effect that February. The City’s parking review page documents it. This is a big deal on narrow lots, where a required parking space and its driveway would otherwise eat the side yard and force a smaller building. You can still provide parking — you’re just not forced to.
When you’ll still need a minor variance
As-of-right has a boundary. The moment your design exceeds the as-of-right zoning — too tall, footprint over the coverage cap, a setback you can’t meet — you’re into a minor variance at the Committee of Adjustment. That’s a separate process with a hearing and a possible appeal. The lesson: design to the envelope, not past it, and you keep the fast path. Push past it and you’ve signed up for the slow one. See is your lot eligible for how to read your zone’s limits.
Stacking a fifth unit
A fourplex isn’t always the end. If your lot abuts a public laneway, a laneway suite is a separate as-of-right permission (city-wide since 2019). If it doesn’t, a garden suite in the rear yard may fit (city-wide since 2022). Either one adds a unit beyond the main building’s four. That’s how a standard lot can reach five homes without ever touching a rezoning.
How this stacks against the province
Ontario’s Bill 23 (Royal Assent Nov 28, 2022) set a floor of three units as-of-right on serviced residential parcels province-wide, per the ERO notice. Toronto went past it — to four city-wide, and five or six in nine wards. When you read “three units” in provincial coverage, remember Toronto exceeded it. Your city ceiling is four, not three.
The honest version
The city-wide fourplex is the most useful permission most Toronto owners have never used. Four units, a house-sized envelope, no parking, no rezoning, no hearing. Confirm your lot is Neighbourhoods-designated, design to the envelope, and price development charges before you commit.
Start with the Toronto Multiplex hub, or check your lot against the by-law. PlexCheck stamps the zone from the City layer at your address and shows the unit ceiling that follows from it.
