Accessory dwelling unit

This information outlines the requirements for building a new Accessory Dwelling Unit (ADU). Before you begin to design or construct an ADU review the following.

Accessory dwelling units (ADUs) are permitted throughout Ontario on single-detached, semi-detached and street townhouse lots. A maximum of three (3) dwelling units are permitted on a serviced lot. The unit(s) can be located within, or as an addition to an existing dwelling, or in a detached (accessory) structure. Each dwelling unit requires one parking space. For example, where there are 3 units, 3 parking spaces are required.

Three dwelling units are permitted on a serviced lot based on the following configuration(s):

• Three (3) residential units in a detached house, semi-detached house or townhouse if there are no residential units in an accessory structure;
• Two (2) residential units in a detached house, semi-detached house or townhouse if there is no more than one (1) residential unit in an accessory structure;
• One (1) residential unit in an accessory structure if the detached house, semi-detached house or townhouse contains no more than two (2) residential units and no other accessory structures contain any residential units.

Zoning requirements for ADUs include:

• Units located at or above grade are a maximum of 50% of the gross floor area of the principal dwelling or 110 m², whichever is lesser;
• Basement units may occupy the entire basement area, however, *ADU’s are not permitted in the basement of dwellings that are located in the floodplain;
• Parking spaces can be provided in a tandem arrangement; and
• Minimum of 50% of the front yard shall be maintained as landscaped open space.

Single-Detached Accessory Dwelling Unit

Where space allows and parking can be accommodated, single-detached dwellings have the ability to accommodate up to 3 units. The ADU’s can be on the ground floor, second floor, basement*, an addition or in a detached (accessory) structure. Each must be a self-contained unit that has:

• A clearly identified entrance with direct access from the outdoors
• Minimum 1 kitchen
• Minimum 1 bathroom
• Maximum 2 bedrooms

Semi-Detached Accessory Dwelling Unit

Where space allows and parking can be accommodated, semi-detached dwellings have the ability to accommodate up to 3 units. The ADU’s can be on the ground floor, second floor, basement*, an addition or in a detached (accessory) structure. Each must be a self-contained unit that has:

• A clearly identified entrance with direct access from the outdoors
• Minimum 1 kitchen
• Minimum 1 bathroom
• Maximum 2 bedrooms

Townhouse Accessory Dwelling Unit

Where space allows and parking can be accommodated, townhouse dwellings have the ability to accommodate up to 3 units. The ADU’s can be on the ground floor, second floor, basement*, an addition or in a detached (accessory) structure. Each must be a self-contained unit that has:

• A clearly identified entrance with direct access from the outdoors
• Minimum 1 kitchen
• Minimum 1 bathroom
• Maximum 2 bedrooms

Note: This information is current as of May 2023 and is subject to change as applicable legislation and regulations are amended by the Province of Ontario and/or City of Brantford.