Additional Residential Units (ARUs)

Additional residential units are not permitted:

• In any cellar or basement within the lands identified as ‘Sewer Surcharging’ and ‘Sewer Surcharging (Combined Storm and Sewer Systems)’;
• On lands identified as ‘Sewer Capacity Limitations’;
• On lands identified as ‘Loughborough Lake’;
• On a lot containing two or more dwelling units, a garden suite, boarding house, or lodging house; and
• On lands subject to natural hazards or on any lands otherwise identified as a natural hazards area through a site-specific investigation or analysis.

To construct or legalize an additional residential unit on a property that is located within the areas noted above you may need an individual analysis. You may require a site-specific zoning bylaw amendment.

Note: To establish an additional residential unit in areas identified as ‘Water Supply/Water Quantity’ and ‘Servicing Capacity (Cana Subdivision)’, you must apply for the removal of a holding symbol.

The gross floor area of a second residential unit can be equal to or less than that of the principal dwelling.

According to the zoning bylaw, gross floor area includes the total area of each floor, whether above or below grade, as well as finished attic space. This measurement is taken between the outside of the exterior walls or between the exterior walls and the center line of party walls dividing the building from another. However, it excludes: open porches, balconies and attached garages for vehicle storage.

An additional residential unit requires at least one parking space that can be provided in a tandem (one vehicle behind the other) arrangement.​​​​​​​

You must provide safe entrance and exit in accordance with the requirements of the Building Code.

Owners are required to legalize additional units to ensure the unit meets the appropriate Building Code requirements.

Be aware that renovations may be required to bring the dwelling up to zoning and Building Code compliance. An inspection conducted by a Building Inspector will determine any existing deficiencies and any required renovations to meet the requirements.

We will assign a new unit number to assist emergency services, home delivery, and mail services according to the building permitting and zoning review process, to recognize your additional residential unit

Owners of additional residential units must adhere to the responsibilities outlined within the Residential Tenancies Act.

Additionally, all property owners must adhere to maintenance requirements beyond the Building Code and zoning provisions, in compliance with the City's Property Standards Bylaw, which sets out standards for the reasonable upkeep and maintenance of buildings and properties, including responsibilities such as yard maintenance and snow removal.