A. Sleeping Areas: At least one smoke detector shall be installed to protect each sleeping area. A sleeping area is defined as the area or areas of the family living unit in which the bedrooms or sleeping rooms are located. Where bedrooms or rooms ordinarily used for sleeping are separated by other-use areas (such as kitchens or living rooms, but not bathrooms or closets), they shall be considered as separate sleeping areas for the purposes of this Section.
B. Common Areas: At least one smoke detector shall be installed in the interior common area at each level of the multiple-family dwelling containing sleeping areas, in such a manner as to assure that rising smoke is not obstructed in reaching the detector and the detector intercepts rising smoke before it reaches any sleeping area. In furtherance of this goal, smoke detectors shall be located on the ceiling not less than four inches (100mm) from a side wall to the near edge, or if on a sidewall, between four inches and twelve inches (100mm and 300mm) down from the ceiling to the top of the detector, and within fifteen feet of all rooms used for sleeping purposes, with not less than one detector per living level (common areas).