When does a house need two exits in Ontario?
A typical detached house needs only one exit. A second exit or independent means of egress is required in situations like dwelling units whose only escape passes through another unit, or shared egress arrangements in houses with secondary suites.
Paraphrased for clarity — open this provision in the BUILDAiD Library for the exact wording.
For a single-family home, one properly designed exit is fine because bedroom windows provide emergency escape. The two-egress question really arises with basement apartments and duplex conversions: where two units share one exit stair, the code demands compensating measures such as fire separations, interconnected smoke alarms, or a second means of egress, and older-house retrofits under the Fire Code follow parallel logic. Get the egress strategy confirmed at design stage; adding a second stair after framing is expensive and sometimes physically impossible.
A normal house only needs one exit door because bedroom windows serve as backup escapes. Two ways out usually becomes an issue when you add a basement apartment and both homes would depend on the same stair.
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This page is provided for general information. Building code requirements depend on your specific project, occupancy and municipality, and code editions change. Always verify requirements against the current Ontario Building Code and confirm with your local building department.