(a) Each habitable room shall have an aggregate glazed window area of not less than eight (8) percent of the gross floor area for natural lighting with a minimum of fifty (50) percent of that glazed area able to be opened for ventilation. When the cabana encloses windows of the manufactured home or mobilehome, park trailer, or travel trailer required for light and ventilation, the window area of the cabana shall be not less than the total area of windows enclosed by the cabana.

(b) A bathroom, toilet room, or service room shall have an aggregate window area of not less than three (3) square feet, except where an approved mechanical ventilation system is provided. When a service or storage room does not enclose or obstruct a window of the manufactured home or mobilehome, park trailer, or travel trailer, no additional window area is required.

(c) Where ventilation of a room is by natural means, openings such as windows, skylights, grilles or gravity vents shall have a minimum net free cross-sectional area opening to the outer air equal to five (5) percent of gross floor area.

(d) Required windows of a cabana shall open to an open space, either directly or through a porch or awning having a minimum clear height of not less than six (6) feet two (2) inches. Such porch or awning shall be at least fifty (50) percent open on the side opposite the windows.

(e) For bathrooms, toilet rooms or service rooms, where the net free cross-sectional area of available natural ventilation is less than five (5) percent of the gross floor area, an approved system of mechanical ventilation and artificial light may be used in lieu of required natural light and ventilation.

(f) Where mechanical ventilation is installed, it shall be capable of producing two (2) air changes per hour with not less than one-fifth ( ¹/₅ ) of the air supply taken from outside the cabana, except that in bathrooms, toilet rooms or service rooms, the mechanical ventilation system, connected directly to the outside, shall be capable of providing five (5) air changes per hour.