Additional Residential Units

An Additional Residential Unit, or ARU, is a separate and self-contained dwelling unit on the same property as a single detached, semi-detached or street townhouse dwelling. These units also have many common name references, including being called an additional dwelling unit (or ADU). When they are located in a separate building they could be called a backyard home, granny-flat, tiny home or a garden suite temporary form of additional dwelling as a garden suite. When attached or above a garage, some have been referred to as a coach house or carriage house unit. When part of the main residential building they are in the form of duplex, triplex, fourplex, stacked-townhouse, in-law suite, secondary suite or basement apartment.  

For the purposes of the City’s land use and this guide, these forms are all names of Additional Residential Units (ARUs). 

Click here to view the ARU Guidebook: ARU Guidebook 2026