Toronto Zoning Feasibility

ZoneWise reads Toronto, Ontario zoning directly from City of Toronto Zoning By-law 569-2013 and the City's authoritative GIS mapping, then tells you in plain language what a residential property can support: houseplexes, secondary suites, laneway suites and garden suites, with the by-law section cited beside every number.

Toronto's residential zones, in plain language

Most low-rise residential land in Toronto sits in five Chapter 10 zone families:

• R (Residential): the broadest low-rise family, permitting the widest range of building types, including apartment buildings, subject to the values on the zoning map for each lot.
• RD (Residential Detached): detached houses.
• RS (Residential Semi-Detached): semi-detached houses, plus detached.
• RT (Residential Townhouse): townhouses, plus semi-detached and detached.
• RM (Residential Multiple): multiple-unit low-rise dwellings.

Toronto is unusual in that several standards, such as lot coverage, density and, in some zones, the number of units, are set per parcel by overlay maps and by numeric values in the zone label on the Zoning By-law Map rather than by a single citywide number. ZoneWise detects your zone from the City's GIS and reports overlay-driven values honestly: where a number cannot be verified for your parcel, the report says NOT VERIFIED with the reason, never a guess.

What you can build

Toronto's residential permissions have changed significantly through a series of amendments in recent years. The current ZoneWise pack reflects the consolidated by-law including the houseplex amendments:

• Houseplexes: a detached houseplex of up to four dwelling units (duplex, triplex, fourplex) is a permitted building type citywide in the R, RD, RS, RT and RM zones (By-law 648-2025). Within the Sixplex Overlay areas, five or six units are permitted (By-law 654-2025).
• Secondary suites (including basement apartments): permitted in a detached house, semi-detached house or townhouse, one per dwelling unit, with no resident parking required (s.150.10).
• Laneway suites and garden suites: living accommodation in an ancillary rear-yard building; a laneway suite needs a lot line abutting a lane, a garden suite does not, and a lot may have one or the other, not both (s.150.8, s.150.7).

Whether a specific configuration works on your lot depends on the zone standards, your lot's dimensions, the overlay values on the zoning map, and any Chapter 900 site-specific exception, which is exactly what a ZoneWise analysis compares, standard by standard, with citations.

Frequently asked questions

Does Toronto use the term ADU or ARU?

Neither. By-law 569-2013 has no single umbrella term: it regulates Secondary Suites, Laneway Suites, Garden Suites and Houseplexes separately, each with its own rules. ZoneWise uses the by-law's own terms in Toronto output.

How many units can I build on a Toronto residential lot?

A detached houseplex of up to four units is permitted citywide in the R, RD, RS, RT and RM zones; within the Sixplex Overlay, up to six (By-laws 648-2025 and 654-2025). Overlay values and site-specific exceptions can change the answer for a particular lot.

Can I add a basement apartment?

A secondary suite is permitted in a detached house, semi-detached house or townhouse, limited to one per dwelling unit and 45 percent of the unit's interior floor area, except that a basement suite in a one-storey detached house may occupy the whole basement (s.150.10). No resident parking is required.

What is a Chapter 900 exception?

A site-specific set of regulations, marked by an x-number in the zone label on the Zoning By-law Map, that governs over the standard chapters and can override base standards entirely. ZoneWise discloses exception risk on every Toronto result.

More questions and answers →

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