(a) In general. — All spaces or rooms shall be provided sufficient light so as not to endanger health and safety. All spaces or rooms shall be provided sufficient natural or mechanical ventilation so as not to endanger health and safety. Where mechanical ventilation is provided in lieu of the natural ventilation, such mechanical ventilating system shall be maintained in operation during the occupancy of any structure or portion thereof.
(b) Light in habitable rooms. — Every habitable room, except kitchens, toilet rooms, basement or cellar rooms and interior rooms of townhouses and row houses, shall have at least 1 window facing directly to the outdoors, a court or a porch. Every habitable room, except kitchens and toilet rooms, shall have at least 1 door or window which can be opened to adequately ventilate the room. Kitchens, toilet rooms without windows, basement or cellar rooms and interior rooms of townhouses and row houses shall have natural or mechanical ventilation.
(c) Common halls and stairways. — Every common hall and stairway in every building, other than 1-family dwellings, shall be adequately lighted at all times with an illumination of at least a 60 watt light bulb. Such illumination shall be provided throughout the normally traveled stairs and passageways.
(d) Other spaces. — All other spaces shall be provided with natural or artificial light of sufficient intensity and so distributed as to permit the maintenance of sanitary conditions and the safe use of the space and the appliances and fixtures.
(e) Toilet rooms. — Every bathroom and water closet compartment shall comply with the light and ventilation requirements for habitable rooms as required by subsection (b) of this section except that a window shall not be required in bathrooms or water closet compartments equipped with an approved mechanical ventilation system.
(f) Cooking. — Primary cooking facilities shall not be permitted in any sleeping room or dormitory unit, except for efficiency apartments.
(g) Separation of unit. — Dwelling units shall be separate and apart from each other. With the exception of cribrooms or rooms accommodating persons with disabilities, sleeping rooms shall not be used as the only means of access to other sleeping rooms.
(h) Privacy. — Hotel units, lodging units and dormitory units shall be designed to provide privacy and be separate from other adjoining spaces.
(i) Common access. — A habitable room, bathroom or water closet compartment which is accessory to a dwelling unit shall not open directly into or be used in conjunction with a food store, barber or beauty shop, doctor's or dentist's examination or treatment room or similar room used for public purposes.
(j) Basement rooms and cellar rooms. — Basement and cellar rooms partially below grade shall not be used for sleeping purposes unless the basement and cellar room (or rooms) is (are) within the specifications for sleeping rooms as provided for in this chapter.
(k) Dwelling units. — Every dwelling unit shall contain a minimum gross floor area of not less than 150 square feet for the first occupant, and 100 square feet for each additional occupant. The floor area shall be calculated on the basis of the total area of all habitable rooms.
(l) Area for sleeping purposes. — Every room occupied for sleeping purposes by 1 occupant shall contain at least 64 square feet of floor area.
(m) Overcrowding. — If any room used for residential purposes is overcrowded as defined in § 4106(27) of this title, the code official may order the number of persons sleeping or living in said room to be reduced.
(n) Prohibited use. — It shall be prohibited to use for sleeping purposes any kitchen, nonhabitable space or public space.
(o) Minimum ceiling heights. — Habitable rooms shall have a clear ceiling height over the minimum area required by this chapter at not less than 7 feet, 4 inches, except that in attics, basements, or top half-stories the ceiling height shall be not less than 7 feet over not less than one-third of the minimum area required by this chapter when used for sleeping, study or similar activity. In calculating the floor area of such rooms, only those portions of the floor area of the room having a clear ceiling height of 5 feet or more may be included.
(p) Minimum ceiling heights in mobile homes. — Habitable space in a mobile home shall have a minimum ceiling height of 7 feet over 50 percent of the floor area, and the floor area where the ceiling height is less than 5 feet shall not be considered in calculating floor area.
(q) Required space in mobile homes. — Every mobile home shall contain a minimum gross floor area of not less than 150 square feet for the first 2 occupants, and 100 square feet for each additional occupant.