Are hallway doors allowed below 760 mm in an Ontario house?

Table 9.5.5.1. of the 2024 Ontario Building Code sets minimum doorway sizes for dwelling units. For rooms not otherwise listed, the minimum is 760 mm wide by 1 980 mm high. A hallway door serving a room in that category cannot be narrower than 760 mm under that table.

Table 9.5.5.1. gives other sizes for specific doors: 610 mm by 1 980 mm for bathrooms, walk-in closets and rooms off 710 mm hallways, and 810 mm by 1 980 mm for doors to stairs leading to a floor with finished space, doors in at least one line of passage to the basement, and utility rooms. A hallway door outside those categories falls under the 760 mm size.

One practical point: replacing a door in the same size opening is on the City of Ottawa's exempt list, while enlarging or relocating a door is on its permit list. Widening a doorway that is narrower than the 760 mm size is enlarging it.

If the house is individually designated under the Ontario Heritage Act, check the designation by-law with City heritage staff before altering any doorway, even one that is the same size, because building-permit exemptions do not apply to designated heritage properties.

The carpenter who does the work can confirm whether the existing frame and rough opening meet the table's dimensions, but the City's Building Code Services can tell you exactly what the permit process looks like for your specific situation, which is the right place to start before any framing is touched.