Garden suites in Toronto: size, height and setback rules

A garden suite is a small, separate rental home built in the backyard of an existing house. Toronto has allowed them as-of-right since February 2022, which means no rezoning is needed — only a building permit — as long as the project meets the zoning standards. Council amended those standards in 2025. Here is what the current rules say, in plain terms.

Where garden suites are permitted

Garden suites are permitted in Toronto’s residential zones: R, RD (detached), RS (semi-detached), RT (townhouse) and RM (multiple). A building permit is required, but a garden suite that complies with the zoning standards does not need a rezoning.

How big can a garden suite be?

• Maximum gross floor area: 120 square metres (about 1,290 sq ft).
• If the suite is a single storey, the maximum is 60 square metres (about 645 sq ft).
• The garden suite must also be smaller than the main house on the lot.
• Two storeys are possible where the site and the zoning standards allow it.

Height and distance from the house

• If the suite is less than 7.5 m (about 24.6 ft) from the main house, its maximum height is 4.0 m (about 13 ft).
• If it is 7.5 m or more from the house, the maximum height rises to 6.3 m (about 20.7 ft).
• The suite must be at least 4.0 m from the house if it is 4.0 m tall or less, and at least 7.5 m away if it is taller. A defined area of the east end, bounded roughly by Coxwell, the Don River, Victoria Park and the lake, uses a 5.0 m separation for taller suites.

Setbacks and lot coverage

• Rear yard: at least 1.5 m (about 5 ft). On lots deeper than 45 m (about 148 ft), the greater of 1.5 m or half the building height. Add 1.5 m if the rear lot line abuts another residential lot and the suite has windows above 4.0 m.
• Side yard: at least the house’s required side yard or 1.5 m, whichever is greater. Corner lots have their own rules, including a 6.0 m setback if the suite contains a parking space with street access.
• Lot coverage: all buildings together may not exceed 45% of the lot, or the garden suite is left out of that calculation and all accessory buildings combined must stay within 20% of the lot area.

Development charges and other fees

Toronto exempts garden suites from development charges (By-law 1137-2022) and from parkland dedication requirements. That removes a cost that can be significant on other new units.

Can you add one to a multiplex lot?

Often, yes — where the lot has enough depth and coverage left after the multiplex is placed. A garden suite behind a fourplex is a fifth rental unit on the same lot. Whether it works depends on your lot size, the multiplex footprint, trees, servicing and the coverage limits above, which is why it needs a lot-specific review rather than a rule of thumb.