Secondary Suite Rules in Ontario: What Is Allowed (2026)

Navigating the secondary suite rules in Ontario is crucial for any homeowner looking to add a rental unit. Recent legislative changes have made it easier to create additional residential units (ARUs). However, strict adherence to the Ontario Building Code is mandatory. Key secondary suite rules in Ontario include proper fire separations, minimum ceiling heights, adequate egress windows, and independent heating or ventilation controls. If you are planning a project, check out our basement apartment construction in Cornwall offerings. Ground Level Construction manages the entire permit process to ensure your new suite is 100% legal and safe.