Short answer: Yes, you can build a permanent backyard home in Markham. Under Zoning By-law 2024-19 it is called a garden home, not a garden suite. It needs a building permit and registration with Markham Fire and Emergency Services. On a lot over 500 m² it can have up to 60 m² of floor area and be 4.0 m high.
Key takeaways
| Question | Short answer | Source |
|---|---|---|
| What to call it | Garden home (permanent); a "garden suite" is temporary and needs a Temporary Use By-law | By-law 2024-19, s. 4.9.10 |
| Permit | Building permit via ePLAN, then Fire registration | Markham homeowner guide |
| Floor area | 15 m² on lots ≤ 500 m²; 60 m² on larger lots | s. 4.8.1.2 b–c |
| Height | 4.0 m on lots ≤ 4,000 m²; 5.5 m on larger lots | s. 4.8.1.2 d |
| Setbacks | 1.2 m side and rear (0.5 m with a blank wall on lots under 4,000 m²); 4.0 m from other buildings if 15 m² or more | s. 4.8.1.2 e; 4.8.1.1 b |
| Unit limits | With a garden home, only one more unit inside the house; none in GWY1 or on TRCA hazard lands | s. 4.9.9 e–f |
Garden home vs garden suite
Markham's By-law 2024-19 (office consolidation, July 20, 2026) defines three backyard terms:
- Garden home: a dwelling unit in an accessory building in the rear yard of a lot not accessed by a lane.
- Coach house: a unit mostly above a detached garage, in the rear yard of a lot accessed by a lane.
- Garden suite: a temporary, portable dwelling unit regulated under the Planning Act.
A garden suite in this legal sense is permitted only through a Temporary Use By-law (s. 4.9.10). It must then be portable, in the rear yard, at most 60 m², set back 6.0 m from the house, no taller than 4.5 m, within 30.0 m of the street-access lot line, reached by a 1.2 m clear path, and outside the Official Plan's Special Policy Area. For a permanent home, the garden home rules below apply.
The by-law clauses that size it
- Floor area (s. 4.8.1.2 b–c): 15 m² above average grade on lots of 500 m² or less, 60 m² on larger lots. It is 15 m² where the main building has no exterior side yard and no interior side yard setback of 1.2 m or more.
- Height (s. 4.8.1.2 d): 4.0 m on lots up to 4,000 m²; 5.5 m above that.
- Side and rear setbacks (s. 4.8.1.2 e): 1.2 m, or 0.5 m on lots under 4,000 m² where the wall facing the lot line has no doors or windows. If the building sits between the house and an interior side lot line, it needs the house's required interior side yard.
- Separation (s. 4.8.1.1 b): 4.0 m from any other building for an accessory building of 15 m² or more; 1.8 m if smaller.
- Hazard lands (s. 4.8.1.1 a): no more than 15 m² on hazardous lands or sites, and never in a front yard.
Markham's Coach Houses and Garden Homes guide (revised April 2026) summarizes the same numbers for lots under By-law 2024-19. If your lot is under an older by-law, confirm the zoning through the City's Property Details Search or a Zoning Search. For build options and our approach to a Markham lot, see garden suites in Markham.
Additional unit limits (s. 4.9.9)
- Additional units are only permitted on a lot with a detached, semi-detached or townhouse dwelling.
- Where one unit is in an accessory building, only one additional unit is allowed inside the house.
- Only one dwelling unit entrance is allowed in a main wall facing a street, unless the second is below grade.
- Entrances reached from the interior side yard must be at least 1.2 m from the interior side lot line, with no stairs within 1.2 m of it.
- No additional units in a GWY1 zone or on TRCA-prescribed hazard lands.
The by-law also points to Ontario's O. Reg. 462/24 for certain modified standards. See additional residential units in Ontario.
Permit, inspections and registration
- Apply online at Markham's ePLAN portal. An application has four parts: forms, documents, construction drawings and permit fees.
- Drawings can be prepared by a BCIN-qualified designer (House or Small Buildings), a licensed architect, a professional engineer, or a homeowner who takes responsibility for the Building Code requirements.
- Inspections are booked at least 24 hours ahead through ePLAN, at these stages: footings, framing, plumbing and mechanical rough-in, insulation and vapour barrier, fire separations where they apply, and occupancy.
- Fire registration with Markham Fire and Emergency Services comes after construction. It carries a fee and requires proof of insurance covering both units.
Source: the City's homeowner guide. Start with our free feasibility check. Other permit guides: Mississauga, Toronto, Vaughan, Brampton and Oakville. New to the idea? Start with what a garden suite is. For the build method, see modular vs site-built.
To compare Markham with other cities, see the GTA garden and laneway suite rules comparison.
FAQs
Sources
- City of Markham — Zoning By-law 2024-19, office consolidation July 20, 2026 (s. 4.8.1.1, 4.8.1.2, 4.9.9, 4.9.10; definitions)
- City of Markham — Coach Houses and Garden Homes: Guide for Homeowners (rev. April 2026)
- Ontario — O. Reg. 462/24, Additional Residential Units
Disclaimer: Figures cited are market estimates provided for information only and are not a quote. Municipal rules, fees, and programs change — always verify current requirements with your local authority. Modular X provides exact pricing only after a site-specific feasibility review.