What is the difference between natural and artificial light?
A. Per Seattle Residential Code Sec R303.1 (pg 44), all habitable rooms require window area glazing equal to either 8% of floor area or, as an exception, artificial light providing an average illumination of 6 footcandles over the area of the room measured at a height of 30″ above floor level. Rooms such as kitchens and bathrooms do not have natural light requirements. See CAM 303A, Common Seattle Residential Code Requirements, for more information.
