Throughout the City of Cambridge, any individual lot containing a single detached dwelling, semi-detached dwelling or townhouse dwelling may contain up to 2 additional residential units, for a total of 3 units, in either of the following configurations: 

  • Up to 2 units within the main residential building, and 1 additional unit within a detached accessory structure; or
  • Up to 3 units within the main residential building.   

Additional Residential Units can be created through: 

  • the conversion of existing space within the main residential building
  • an addition to the main residential building
  • the conversion of an existing accessory structure on the lot
  • the addition of a new accessory structure on the lot

Additional Residential Units must comply with the City's Zoning By-law 150-85, and the City's Additional Residential Unit (ARU) By-law 23-077.

Construction or conversion of a new residential unit first requires the issuance of a building permit. Occupancy of the unit must be approved by the City of Cambridge Building Services Division.  Development Charges typically apply to new additional residential units, unless the lot is within a special exemption area.  

For guidance on preparing a building permit application for one or more additional residential units, please refer to the City's Building Permit Requirements for Creating an Additional Residential Unit Guidelines

For more information on ARU By-law 23-077,  email

For more information on the permit application process or Ontario Building Code for ARUs, email

 Other Information