Is A Bathroom Fan Required By Code. Make use of bathroom or kitchen exhaust fans which are already being installed. A specific ventilation requirement for bathrooms began in the 1946 Uniform Building Code with the citation shown below courtesy of Jerry Peck.
A window is not required in a bathroom when a bathroom exhaust fan is provided. Bathroom ventilation codes require a bathroom exhaust fan to vent to the exterior not the attic for health and structural reasons. When natural ventilation requirements 3 sq ft of windows 50 operable cant be met the bath should be vented by either a 20 cfm continuous vent fan or a 50 cfm vent fan that is intermittent or switched.
A window is not required in a bathroom when a bathroom exhaust fan is provided.
Since the window had to be a minimum size for ventilation likewise the exhaust fan must have a minimum exhaust rate which is determined in accordance with Section M1505 of the International Residential Code. In those areas ventilation in bathrooms is required. Although a single-point exhaust fan such as a bathroom fan could be used to provide code-required whole-house ventilation this strategy is not recommended. Very important thing to remember is to properly size your bathroom vent exhaust fan.
