Ontario changed the Planning Act in 2019 to require municipalities to adopt official plan policies and pass zoning by-laws that allow one additional residential unit in the primary residence (i.e., second units) and one in an existing or new building or structure ancillary to the primary residence (i.e., tiny home, garden suite, coach house, laneway suite). This change was designed to help increase the supply of housing and create more options for families.

Municipalities in Ontario are at different stages of developing these policies, so Members should check with local municipalities first before advising clients.

What is a second unit?

A second unit is a self-contained dwelling unit with a private kitchen, bathroom facilities and sleeping areas. Second units can be built in any part of a house. It can be all on one floor or on multiple levels. Homeowners usually build second units in the basement or attic. Building Code rules can vary depending on where the second unit is located.

Is your home detached, semi-detached or a rowhouse that is more than five years old? Are you considering renovating it to add a second unit? If the answers are yes, then this guide can help you.

Note: If your house is less than five years old, different Building Code rules apply. Contact your local building department for more information.

Before deciding to add a second unit, it is important that you first speak with your local municipal planning and building departments. They can tell you whether you are allowed to add a second unit on your property and answer any questions that you have related to local zoning, the Building Code and other by-laws.

There are several important factors you need to consider before adding a second unit, including:

• applicable municipal zoning requirements
• necessary building permits
• designing your unit to comply with the Building Code
• required building inspections during construction

It is important to meet planning and Building Code requirements. Doing so will help ensure that your house and second unit are legal, safe and healthy places to live.

More information is available on the provincial website at Ontario.ca/HousingInnovation.