Section 410.280 - Natural and Mechanical VentilationThe owner shall provide for each habitable room, and room containing a toilet, bathtub or shower, ventilation to the outdoors consisting of:
(A) windows, skylights, doors or transoms in the exterior walls or roofs that can be easily opened to a minimum of 4% of the floor area of that habitable room or room containing a toilet, bathtub or shower, provided, that a skylight which if open exposes the interior of the dwelling to direct rainfall shall not satisfy this requirement; or(B) Mechanical ventilation capable of exhausting air at the following rates: Occupancy Classification | Required Air Changes Per Hour |
Habitable rooms other than bath, toilet or shower rooms | 2 |
Bath, toilet or shower rooms | 5 |