(A)   Habitable living space.
      (1)   Every dwelling unit shall contain at least 150 square feet of floor space for the first occupant, and at least 100 additional square feet of floor space for every additional occupant. The floor space shall be calculated on the basis of total habitable room area.
      (2)   Every room occupied for sleeping purposes shall contain at least 70 square feet of floor space, and every room occupied for sleeping purposes by more than one occupant shall contain at least 50 square feet of floor space for each occupant.
      (3)   At least one-half of the floor area of every habitable room, bathroom, water closet compartment, and hallway shall have a ceiling height of not less than seven feet. The floor area of the part of any habitable room or other rooms as mentioned above where the ceiling height is less than five feet shall not be considered as part of the floor area in computing the total floor area of the room for the purpose of determining its maximum permissible occupancy.
      (4)   A room used as a kitchen shall comply with the ceiling height requirement, i.e., shall not be less than seven feet. Such designated rooms (kitchens) shall contain a sink and an area for food preparation. The food preparation area shall not be the required sink basin.
   (B)   Basements. Space below the first story of a building may be used as a dwelling unit or guest room, provided that it is free of dampness and complies with all requirements of this chapter and of all other applicable laws, codes, and ordinances.
   (C)   Natural lighting.
      (1)   Generally. Every habitable room shall have at least one window or skylight facing directly to the outdoors. The minimum total window area measured between stops for every such room shall be 10% of the floor area of the room. Whenever walls or other portions of structures face a window of any such room and such light-obstructing structures are located less than three feet from the window and extend to a level above that of the ceiling of the room, the window shall not be deemed to face directly to the outdoors and shall not be included as contributing to the required minimum total window area. Whenever the only window in a room is a skylight type window in the top of such room, the total window area of that skylight shall equal at least 15% of the total floor area of such room.
      (2)   Exceptions. This does not apply to rooms used for sleeping purposes.
   (D)   Natural ventilation. Natural ventilation shall be provided in accordance with the Michigan Residential Code.
   (E)   Exits. Every dwelling unit and guestroom shall have access to at least one approved unobstructed exit. All exits must comply with the requirements of the Building Code of the city.
   (F)   Security. All individual dwelling units and rooming units shall be equipped with the following minimum security devices.
      (1)   All windows and doors to the exterior of a dwelling unit shall be equipped with appropriate locking devices.
      (2)   Exterior doors and dwelling unit doors which are required by this chapter as means of exit shall not be equipped with locks which require a key for operation from the side from which exit is to be made.
(Prior Code, § 151.066)  (Ord. D-1595, passed 7-31-1989, effective 9-1-1989; Ord. D-1647, passed 11-18-1991, effective 12-9-1991; Ord. D-1911, passed 1-28-2002, effective 2-7-2002)