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OBC DIVISION B · PART 3 · SECTION 3.7 — HEALTH REQUIREMENTS

Can a bedroom or sleeping room have no window under the Ontario Building Code?

In Part 3 buildings, sleeping rooms without openable exterior windows must be mechanically ventilated in accordance with Part 6, and life-safety measures, smoke alarms, egress design and suite fire separations, still fully apply. Part 9 houses have stricter bedroom window rules.

Code reference
Health provisions for Part 3 buildings tie sleeping room ventilation to either openable windows to the outdoors or a mechanical ventilation system designed under Part 6 to deliver the required outdoor air. This differs from Part 9 housing, where bedrooms are also subject to specific egress window requirements that Part 3 addresses instead through its egress and fire safety systems.
OBC Division B, Section 3.7.

Paraphrased for clarity — open this provision in the BUILDAiD Library for the exact wording.

What this means in practice

Interior bedrooms appear in hotels, dormitories, care facilities and some condo layouts, and they are generally permissible in Part 3 buildings when mechanical ventilation delivers code outdoor air rates and the fire safety package (detection, alarm, suite separations, sprinklers where required) is complete. Municipal zoning or design guidelines may still push back on windowless bedrooms, and marketing realities often do too. In houses and small buildings under Part 9, bedrooms typically need an egress-capable window, a much stricter test.

Plain language

In larger buildings like hotels and apartments, a bedroom without a window can be allowed if fresh air is supplied mechanically and the fire safety systems are in place. In ordinary houses, bedrooms usually still need a real openable window.

Related questions

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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.