Second Unit Licensing

What is a Second Unit?

A second unit (commonly known as a basement apartment or accessory dwelling unit) is a self-contained living unit (containing cooking, sleeping and sanitary facilities) within a detached, semi-detached house or townhouse.

All second units must comply with the Ontario Building Code, Ontario Fire Code and the Mississauga Zoning By-law.

Building Permit

All second units created after July 14, 1994 require a building permit.

You can check the building permit history of a property online at


All second units must be registered as per the Second Units Registration By-Law 114-16.

Click here for a list of second units in the City of Mississauga that have been registered.

Please note: The registry list is updated the first week of every month

Property Owners that have a second unit are required to complete an "Application to Register a Second Unit" and submit it to the Planning and Building Customer Services Centre on 3rd Floor, 300 City Centre Drive, Mississauga during regular business hours, Monday to Friday, 8:30 a.m. to 4 p.m.

There is no fee to register a second unit. However, there may be other fees associated with second units such as building permit fees and fire inspection fees as part of the required steps in the registration process. (Note: Not including any required design drawings and renovation costs.)
Homeowners who previously obtained a second unit license will be automatically registered.

If you have a second unit and your property does not appear on the registration list, you will need to register the second unit via one of the streams on the www.mississauga.cawebsite.

Adding a Second Unit in an Existing House Resource:

Our members can verify the status of the secondary suite by looking up the property address on the registration list:

MLS® Map of Mississauga