Ontario requires municipalities to permit at least 3 residential units as-of-right on most serviced urban lots under Bill 23 (2022). That means no zoning by-law amendment needed to add a second suite and a garden suite, or up to 3 units in a primary building. Toronto and Ottawa go further, allowing 4 units as-of-right. You still need a building permit and OBC compliance. The building must fit the existing zoning envelope: setbacks, height, and coverage rules still apply.
As-of-right permission strips out the most time-consuming and expensive step in small-scale residential infill: the zoning by-law amendment or minor variance hearing. A project that qualifies as-of-right can go from design to building permit without a planning approval process, reducing a 6-to-18-month approval wait to a few weeks of permit review.
The as-of-right framework for residential units was established in Ontario through Bill 23, the More Homes Built Faster Act, which came into force in late 2022. It overrides local zoning and applies to all Ontario municipalities with urban serviced areas. Individual municipalities can exceed the provincial minimum, but they cannot go below it.
| Municipality | Max units as-of-right | Enabling instrument | Notes |
|---|---|---|---|
| All Ontario municipalities (urban serviced) | 3 units | Bill 23 / Planning Act | Province-wide override. 3 units in primary building, or 2 primary + 1 ancillary. |
| Toronto | 4 units | EHON (City By-law) | Expanding Housing Options in Neighbourhoods framework. Most residential zones. |
| Ottawa | 4 units | Zoning By-law 2026-50 | Enacted March 11, 2026. Applies to urban serviced residential lots. |
| Hamilton | 3 units | Bill 23 provincial floor | Provincial minimum. Council debated fourplexes as-of-right but no by-law as of July 2026. |
| Mississauga, Brampton, Vaughan, Markham, others | 3 units | Bill 23 provincial floor | Conformed to provincial minimum. No local by-law exceeding 3 units as of July 2026. |
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Check my address →As-of-right removes the requirement for a zoning by-law amendment at the Ontario Land Tribunal or a minor variance at the Committee of Adjustment. It does not remove every approval from your path.
Every residential unit, including secondary suites and garden suites, requires a building permit. OBC Division B requirements for fire separation between units (Part 9 and Part 3), egress windows, sound ratings, and structural loading apply in full.
As-of-right only removes the need for a ZBA. The building still has to fit inside the zone's setbacks, maximum height, lot coverage, and floor space index. A lot may be zoned for 4 units and still not physically fit a 4-unit building that meets every rule.
If your lot is within a regulated area (flood plain, wetland, shoreline), you need a conservation authority permit regardless of as-of-right zoning status. The CA permit is issued under the Conservation Authorities Act, not the Planning Act.
A designated heritage property requires heritage permit approval under the Ontario Heritage Act before alterations or additions. As-of-right zoning does not override heritage designation.
Some lots carry site-specific zoning conditions added through prior development approvals or holding symbols (H). These conditions survive the as-of-right override and must be addressed before building.
Bill 23 added s. 16(3) to the Planning Act, which overrides local zoning to permit up to 3 residential units on most urban residential lots. The three permissible configurations are:
Garden suites (detached ancillary residential units on the same lot) are permitted as-of-right under Bill 23, but they must comply with the municipality's garden suite provisions for maximum GFA, setbacks, and height. Some municipalities have adopted specific garden suite by-laws; others rely on the provincial default. Confirm which applies to your lot before starting design.
Toronto went beyond the provincial minimum through its Expanding Housing Options in Neighbourhoods (EHON) initiative. EHON permits up to four residential units as-of-right in most Toronto residential zones, including the formerly single-family "RD" zones that make up most of Toronto's residential land base.
A Toronto fourplex as-of-right project must still comply with the zoning envelope: maximum height (typically 10 metres in residential zones), rear yard setback, lot coverage (typically 35% for principal building, 45% including ancillary), and FSI. A fourplex that meets the envelope can proceed directly to building permit without a planning application. One that needs a height increase or reduced setback still requires a minor variance at the Committee of Adjustment.
Ottawa Council approved By-law 2026-50 on January 28, 2026, and it was enacted on March 11, 2026. The by-law permits up to 4 dwelling units as-of-right on any serviced residential lot in Ottawa's urban area, mirroring Toronto's approach and going one step beyond the provincial Bill 23 floor.
Ottawa's approach is significant because it is the largest Ontario municipality outside Toronto to formally exceed the provincial 3-unit floor. The by-law applies to lots with municipal water and sanitary connections and does not apply to rural lots on well and septic.
The Province considered a blanket Ontario-wide fourplex mandate but has not enacted one as of July 2026. Cities like Hamilton have debated but not adopted local fourplex by-laws. The practical result: fourplexes are only as-of-right in Toronto and Ottawa as of mid-2026. All other municipalities remain at the Bill 23 floor of 3 units.
As-of-right zoning in Ontario means a use or development is permitted under the existing zoning by-law without requiring a zoning by-law amendment (ZBA). For residential infill, it means you can add dwelling units up to the permitted limit and obtain a building permit directly, without going through the Committee of Adjustment or a formal rezoning. You still need a building permit and must meet OBC requirements.
Under Bill 23 (More Homes Built Faster Act, 2022), the province requires all Ontario municipalities to permit at least 3 residential units as-of-right on most urban serviced lots. The 3 units can be: up to 3 units in the primary building, or up to 2 units in the primary building plus 1 unit in an ancillary structure. Toronto and Ottawa go further, allowing up to 4 units as-of-right.
Yes. Toronto's Expanding Housing Options in Neighbourhoods (EHON) framework permits up to four dwelling units as-of-right in most Toronto residential zones. You still need a building permit and must comply with OBC. The building must fit within the applicable setbacks, height, and coverage rules. If the design exceeds any envelope rule, a minor variance at the Committee of Adjustment is required.
No. As-of-right means you do not need a zoning by-law amendment. You still need: a building permit (mandatory), OBC compliance for fire separation, egress, and structural requirements, and a conservation authority permit if your lot is in or near a regulated area. Heritage designation, site-specific zoning conditions, and grading/drainage approvals may also apply.
Yes, in most cases. Development charges are triggered by new residential units, regardless of whether a ZBA was required. Bill 23 exempted "affordable" units under specific definitions, and some municipalities have DC incentive programs for additional residential units (ARUs). Confirm DC applicability with the municipality before building permit submission. The 2026 Canada-Ontario DCRP program applies to multi-unit residential projects, which may overlap with larger infill projects.
PreBuildIQ checks your Ontario address against current zoning, overlays, and approval requirements, including as-of-right unit permissions, in 60 seconds.
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