Secondary suite permits: what Canadian homeowners should check

Start with the municipality and the type of unit

Canadian cities use different terms — secondary suite, additional residential unit, accessory dwelling unit, garden suite, backyard suite or laneway home. Those terms are not always interchangeable, so the local definition matters.

Examples from official municipal sources

Kingston, Ontario: the city says all new and existing additional residential units must comply with the Ontario Building Code and require a permit. It separates new-build units from renovations that convert existing space.

Saskatoon, Saskatchewan: the city's building-permit guidance includes secondary suites and basement developments among common permit projects.

Regina, Saskatchewan: the city lists secondary suites among residential projects that require a building permit.

Laval, Quebec: the city says a permit is mandatory before adding an additional dwelling unit to an existing single-family home.

Questions to answer before designing the suite

• Is the property eligible for another dwelling unit?
• Is the unit inside the existing home or detached?
• Will a new entrance, window or exit be created?
• Are plumbing, electrical, gas or HVAC systems changing?
• What fire separations and life-safety measures apply?
• Are parking, servicing or utility changes required?
• Are there flood, sewer-capacity, heritage or hazard constraints?

Why this is a high-risk project to guess about

A suite changes how part of a property is occupied. That can bring together building and land-use rules that do not apply to a basic cosmetic renovation. Confirm the current municipal route before spending money on drawings or construction.