Section R. 400.4411 - Natural lightRule 411.
(1) Every sleeping room occupied by residents shall have natural light from a source which is equal to not less than 8% of the floor area for that room. A skylight, louver, glass-blocked panel, or similar light-transmitting device shall not be counted for more than 50% of the required area in place of conventional windows and glass doors.(2) Every habitable room shall have artificial light capable of providing not less than 20 footcandles of illumination at a height of 3 feet above the floor.Mich. Admin. Code R. 400.4411