“Secondary suite” means an additional dwelling unit that is located within a single dwelling, semi-detached dwelling or townhouse dwelling.

A secondary suite is a permitted use in any zone where single dwelling, semi-detached dwelling, or townhouse dwelling is a listed use. Contact Planning and Development Services to discuss your proposed development. 

Suites that are not located within a dwelling cannot be considered a secondary suite. Please see the Garden Suites page for information on suites located outside of a dwelling.

General information

• Only one secondary suite may be considered per single dwelling, semi-detached dwelling or townhouse dwelling.
• Secondary suites shall only be considered within townhouse buildings where located:
  • Within a planned site; or 
  • On an end lot with a minimum side setback of 1.2 m; or on any lot located within the HR2 - Hillshire Low to Medium Density Residential and HR4 - Hillshire Low to Medium Density Flex Residential zones. 
• A secondary suite shall not be developed within a dwelling containing a group home minor or group home major, or bed and breakfast. 
• The floor area of a secondary suite must be less than the floor area of the principal dwelling unit.
• When located on a lot less than 0.4 hectares, a secondary suite shall not be developed if there is an existing garden suite on the same lot.
• A minimum of three on-site parking spaces shall be provided (two for the principal dwelling and one for the secondary suite) which conform to parking regulations. Despite this, an on-site parking space for a secondary suite is not required where:
  • • there are a minimum of two on-site parking spaces on the lot;
    • access to the principal dwelling is provided from a lane; and
    • on-street parking is authorized on a road that is adjacent to the lot.
• Shall be a self-contained unit which has a separate private entrance and is comprised of at least a kitchen, washroom and bedroom and where the occupants reside together as a single household.
• Bedrooms shall have at least one outside window or exterior door openable from the inside providing an unobstructed opening of less than 0.35 sq. metres (3.77 sq. feet) in area. No dimension of the openable portion may be less than 380 mm (15 inches).
• Ceiling height minimum for secondary suites is 6.4 ft. (1.95 m)
• Smoke alarms must be hard-wired and interconnected with the main house so they will operate in unison.
• Exit can be provided either by direct exterior exit or an exit with stairs leading from the basement to a main floor entry (that has a doorway to the outside).
• Fire protected walls and ceiling (use of 1/2 inch drywall) are required between a basement suite and the main house as well as around common exits. 
• Electrical, plumbing and gas work must be done by a certified professional (e.g. master electrician, journeyman trades person).
• Heating and ventilation for the suite must be independent from the main house. 
• Gas furnaces and water heaters have to be enclosed in a room with fire protected walls and ceiling (use of 1/2 inch drywall).
• Doors leading to a smoke tight area shall be solid core, wood doors, at least 45 mm thick and have a self-closing device. 
• Water and sewer must be provided through the main house.

Printable brochure - secondary suites (179.2 KB)

Applying for permits

To obtain the necessary permits, you will be required to submit:

• A completed development permit application form with landowner signature.
• A completed building permit application form. 
• Three copies of the site plan (a photocopy of the Real Property Report is preferred) identifying the parking locations and second entrance. 
• Three copies of the floor plans for each level of the entire dwelling (principal and suite) with dimensions and rooms labeled. Window sizes and smoke detector locations must also be shown. 
• Photographs of the exterior of the dwelling (all four sides).
• Current copy of land title (printed within the last 30 days).
• A completed  fire safety plan (84.5 KB) - information on construction fire safety plans and protection requirements. 

Plumbing requirements for basement secondary suites

National Plumbing Code of Canada, clause 2.4.6.4

The following applies to both new construction and renovations/additions. 

Where there is a secondary suite in a basement, all basement fixtures including floor drains must be protected from sanitary sewer backflow. This must be done in such a way that the wastewater from upstairs fixtures cannot backup into the basemen fixtures, even in the event of a clogged building drain. This can be accomplished in a variety of ways. Normally, closed backwater valves can be installed on all branches serving basement fixtures. If this is done, no stack serving the upstairs can be connected to the branch upstream of the backwater valve. Alternatively, a normally open mainline backwater valve may be used provided that all stacks serving the above ground occupancy are connected to the building drain downstream of the backwater valve. Normally, open mainline back water valves can serve only a one-occupancy dwelling. Adding a legal basement suite would then become a two-occupancy dwelling. 

Secondary suite fees

Please see "Secondary Suite " in the current development and building fee schedules. 

Note: The Safety Code Council fee also applies to secondary suites. Please see the current building fee schedule. 

More information: