Toronto’s Fourplex Rules: As-of-Right Multiplexes, Garden Suites and the Missing Middle
Up to 4 units citywide, 5–6 in pilot wards, 3 as a provincial floor — what it means for owners and investors
How many units can a Toronto residential lot have now, and what does as-of-right mean?
Toronto residential areas now allow up to 4-unit multiplexes as-of-right, with no rezoning required.According to the City of Toronto, By-law 474-2023 (adopted May 10, 2023) permits 2–4 units in detached, semi-detached and townhouses citywide. Provincially, Bill 23 (2022) guarantees up to 3 units per residential lot as-of-right, with no development charges on the 2nd and 3rd units. ‘As-of-right’ means that as long as you meet the by-law’s numeric standards, you don’t need a rezoning or minor variance.
Sources: City of Toronto (By-law 474-2023 multiplex, By-law 654-2025 sixplex, garden suite rules, HAF); Ontario ERO (Bill 23 three-unit rule); CMHC / Canada.ca (Housing Accelerator Fund).
‘Missing middle’ has been the watchword of Ontario housing reform. For an owner sitting on a single-detached lot, the concrete change is this: you can now legally add units and rental income without rezoning. But the numbers — 4 units citywide, 6 in a pilot, 3 provincially — get muddled constantly. Here’s Toronto versus the province, kept straight, plus what it means for you.
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Toronto: 4-unit multiplexes as-of-right, citywide
ℹ️Don’t conflate municipal and provincial: Toronto’s citywide as-of-right is 4 units (municipal By-law 474-2023); the provincial Bill 23 floor is 3 units. Toronto chose to go further — it isn’t a provincial mandate.
Provincial floor: Bill 23’s 3 units + DC exemption
Federal lever: the Housing Accelerator Fund
⚠️Six units isn’t citywide. Toronto’s sixplex (5–6 units) is currently a pilot in about 9 wards, not an as-of-right citywide rule. Confirm whether your lot’s ward is covered, and verify current rules with City Planning before you proceed.
2025–2026: the sixplex pilot, but only in some wards
What it means for owners/investors: garden suites are the easiest entry
Frequently Asked Questions
How many units can my Toronto single-detached lot have?
According to the City of Toronto, residential areas now allow up to 4-unit multiplexes as-of-right (By-law 474-2023). Five to six units (sixplex) is currently a pilot in about 9 wards. For your specific lot, feasibility still depends on size, parking, emergency access and tree protection meeting the by-law — verify with City Planning.
Which unit starts attracting development charges?
According to Ontario, Bill 23 exempts the 2nd and 3rd units from development charges and parkland fees. The 4th unit and above may attract charges — confirm per project with the city. That’s part of why many owners start with 2–3 units.
What exactly does as-of-right mean?
It means that as long as your proposal meets every numeric standard in the zoning by-law (height, setbacks, floor area, etc.), you can build without applying for a rezoning or minor variance. Exceed the standards and you’ll still need a variance or rezoning.
Is adding units worth it?
The rental income potential is real, but cost and constraints what govern: whether the lot physically fits a suite, parking and building-code requirements, financing terms, and possible development charges from the 4th unit. Zoning permission is only step one — verify feasibility item by item and do due diligence before deciding.
Arthur Zhao
Real Estate Broker · FRI · ABR · SRS · PSA · MCNE · E-PRO · CLHMS & GUILD Elite · REAIS
VP & Branch Manager, Bay Street Group Inc.
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