Accessory Apartments

What is an accessory apartment?

An accessory apartment is a completely self-contained residential dwelling unit within a single-family dwelling, semi-detached dwelling or townhouse dwelling. Accessory apartments are often referred to as basement apartments, second residential units, in-law suites or secondary suites. The Town has decided to use the terms ‘Accessory Apartment’ and ‘Additional Dwelling’ for these units. Based on the November 2022 passing of the Province’s Bill 23, one additional dwelling may now also be permitted in an accessory structure, provided the main residence on the property has a maximum of two units, and the property is on municipal water and sewers.

Accessory Apartments and additional dwellings must be registered with the Town to be considered legal and must comply with all applicable legislation, including Zoning Bylaw provisions, The Ontario Building Code and the Ontario Fire Code. The process of complying with this legislation can vary depending on the date of establishment of the accessory apartment.

What are the requirements?

A building permit is required for an accessory apartment, if the unit:

  • Is a new proposed unit within a new or existing structure
  • Was established after Nov. 16, 1995 and was not created legally
  • Is proven to have been established before Nov. 16, 1995 on a property with municipal water and sewers, and remedial work is required as a result of a Fire Department inspection, or
  • Was established after May 9, 1977 on a property serviced by private well and/or septic

A house that contains an accessory apartment must comply with the Ontario Building Code and Ontario Fire Code and include: 

  • Fire separations between apartments and common spaces, such as exit corridors, laundry rooms and other spaces that are accessible by both apartments
  • Exits from each apartment
  • Interconnected smoke alarms in all bedrooms and all floors in each apartment
  • Sufficient sizing of existing septic system (a house serviced by a septic system may not be allowed to have an accessory apartment unless the system can be confirmed to support the extra loads)
  • Note: Heating and ventilation upgrades are often required

A property that contains one accessory apartment and is serviced by municipal water and sewers must provide a minimum of two parking spaces. A property that contains one accessory apartment and is serviced by private well and septic must provide a minimum of three parking spaces. The parking spaces must comply with the following:

  • Two of the required spaces cannot block each other in and must have direct access to a public street
  • Only one required parking space can be located within a garage
  • All required parking must be within the property lot lines and meet the minimum size requirements

All accessory apartments must be registered by the Registrar (Town Clerk) or person appointed by the Registrar. 

What do I need?

If only a paper copy is available, contact for information

The permit fee for residential interior renovations is $1.14/ft2 

Contact Us

26557 Civic Centre Rd,
Keswick, ON  L4P 3G1

T: 905-476-4301 / 705-437-2210
F: 905-476-8100

Hours of Operation

Monday to Friday
8:30 a.m. to 4:30 p.m.