Accessory Dwelling Units

An accessory dwelling unit is a self-contained dwelling unit established within or attached to a detached or semi-detached single-family dwelling. To be considered a complete and compliant living space, it must include, at a minimum:

• A bathroom;
• A kitchen;
• A space dedicated to a living area and a bedroom, which may be designed as an openconcept space or as separate rooms.

Assented to on February 21, 2024, Bill 31 (Act to amend various legislative provisions respecting housing) provides a framework and authorises by right the establishment of accessory dwelling units, despite the initial municipal urban planning by-laws. The government's main objective is to encourage gentle density in lower-density residential neighbourhoods. 

Gentle density creates new housing opportunities without altering the architectural character or scale of existing neighbourhoods. In the current context of a housing crisis, this measure facilitates the creation of living spaces while optimising the use of the built environment. The by-right authorisation regime is planned for a period of five years (until August 21, 2029).

By-law 1657 provides a framework for the creation of additional housing units while adhering to the spirit of Act 31. 

Summary of By-Law 1657

Additional dwelling unit projects must also comply with the City’s zoning by-law and building by-law.

1. Before beginning any work, you must submit a permit application for interior renovation to the Urban Planning Department.
   
   Apply for a renovation permit
   
   
2. You must then obtain an occupancy certificate from the Urban Planning Department.
   
   Apply for an occupancy certificate