What your backyard needs to fit a garden suite.
A garden suite is new construction, so the rules are less about the structure itself and more about where it can sit and how it connects to services. Five things decide it: footprint, setbacks from the property line, height, lot coverage, and servicing. And under all of them, whether your property is zoned for one.
Pace out the yard. See what fits.
- Footprint50 m² is within the roughly 60 m² most lots allow.Fits
- SetbacksSits inside 1.5 m from the rear line and 0.6 m from each side.Fits
- Lot coverageBuildings cover 28% of the rear yard. Often capped around 40%.Fits
- HeightDesigned under the limit: roughly 6.0 m flat roof, 6.3 m sloped.Shown on the plans
- ServicingIts own water, sewer and hydro, on a servicing plan with the permit.Shown on the plans
Typical figures, not your bylaw. Hamilton, Burlington, Brantford and Brant each set their own numbers, and trees, easements and the zoning path can change the answer.
The yard can look big and still not fit.
- 01
Setbacks
You can’t build right to the lot line.
- 02
Coverage
The lot can only hold so much building area.
- 03
Servicing
Water and sewer routes can change the design.
What each one actually means.
Directional zoning and building figures, gathered from public building-industry sources rather than a specific municipal bylaw. Every municipality sets its own exact numbers on top of the provincial as-of-right framework, so treat this as a starting point, not your property’s actual limits.
- 01
Footprint
Maximum floor area of the suite itself.
Typical limitRoughly 60 m² (645 sq ft) on most lots; some larger lots allow more.
- 02
Setbacks
Minimum distance from the suite to the property line.
Typical limitRoughly 1.5 m from the rear line, 0.6 m from each side.
- 03
Height
Maximum height of the structure.
Typical limitRoughly 6.0 m for a flat roof, 6.3 m for a sloped roof.
- 04
Lot coverage
How much of the rear yard the suite (and other structures) can occupy.
Typical limitOften capped around 40% of the rear yard, with the rest kept as soft landscaping.
- 05
Servicing
Connection to municipal water, sanitary sewer and hydro.
Typical limitIts own dedicated connections, shown on a servicing plan submitted with the permit.
Setbacks and coverage, first.
A garden suite doesn’t fail on ceiling height the way a basement can. It’s new construction, built to whatever size fits. What it can fail on is fit: a narrow or shallow backyard, mature trees near the build zone, or a rear yard already partly covered by a garage or shed can all eat into the buildable envelope before design even starts.
Services and zoning.
The two requirements people underestimate.
How do utilities reach the suite?
Unlike a basement apartment, a garden suite can’t tap into the house’s existing plumbing and electrical. It needs its own connections, usually trenched across the yard to the house or the street. Submitted as a servicing plan alongside the permit drawings, it’s the single biggest reason garden suites cost two to three times what a basement conversion costs at a similar size.
A clean utility route is a big advantage.Is the unit allowed here?
Ontario’s provincial framework requires most residential lots on municipal water and sewer to allow a garden suite as-of-right: no rezoning or committee hearing for a basic setup. But as-of-right covers the use itself. Setbacks, height, coverage, parking and tree protection are still set locally, and some garden suites were approved under older, temporary-use bylaws instead. The two paths lead to different permit processes.
Check the address before drawing the building.For the full cost comparison, see Basement Apartment vs. Garden Suite. New to the terms? See setback, servicing and as-of-right.
The yard, not the inside.
This page is about the backyard and the structure itself. It doesn’t cover interior requirements like egress windows or fire separation, which are basement-conversion specific. See Basement ADU Requirements for that side of the comparison.
Pick the question closest to yours.
Does my property qualify?
Zoning, parking and servicing for your address.
ADU Terms Glossary
Setback, servicing, as-of-right and the rest, defined plainly.
Basement Apartment vs. Garden Suite
Cost, timeline, zoning path and servicing, compared side by side.
We’ll walk your lot and tell you exactly.
What fits, and which zoning path applies, before you spend anything on drawings.