Is a bathroom window required by code?

No, a bathroom window is not required by the Ontario Building Code if you have proper mechanical ventilation. However, you must have adequate ventilation to prevent moisture problems and meet code requirements.

The Ontario Building Code requires either a window or mechanical ventilation in bathrooms. Most modern bathrooms rely on exhaust fans rather than windows for ventilation. The exhaust fan must be rated for the bathroom size (typically 50 CFM minimum for bathrooms under 100 square feet) and must vent directly to the exterior - never into an attic or crawl space.

In Ottawa's climate, mechanical ventilation is often more effective than windows for moisture control. Windows can create cold spots that lead to condensation problems during our harsh winters. Many homeowners actually prefer windowless bathrooms for privacy and easier tile installation on exterior walls.

If you do have a bathroom window, it must meet specific requirements. Windows in shower areas must be made of safety glass or be positioned outside the "wet zone" (typically 60 inches from the shower head). The window opening mechanism should be accessible and the glass should be tempered if it's within 24 inches of the floor.

For basement bathrooms, windows are rarely practical due to below-grade positioning, making proper exhaust ventilation essential. The fan should be connected to a timer switch or humidity sensor to ensure adequate moisture removal.

City of Ottawa requirements may vary for specific installations - confirm ventilation requirements with your licensed contractor during the permit application process. Proper ventilation planning prevents mold, protects your investment, and ensures code compliance.