Ann Arbor — Ch. 105 Housing Code § 8:502

Unless otherwise provided, no person shall occupy as owner-occupant, or let to another for occupancy, any dwelling or dwelling units which do not comply with the following requirements: (1)
Windows. Every habitable room shall have at least 1 window, sliding glass door, skylight, or other acceptable light transmitting media facing directly to the outdoors. The minimum total glazed area for every habitable room shall be not less than 8% of the habitable floor area of such room. In the case of kitchens, the window space requirements may be reduced or waived by the Planning and Development Services Unit official when there is adequate artificial lighting.
(2) Ventilation. Every habitable room shall have at least 1 window, sliding glass door, or skylight which can easily be opened, or such other device as will adequately ventilate the room. The total area for ventilation shall be at least 4% of the habitable floor area of the room served. Mechanical ventilation may be provided in lieu of natural ventilation if approved by the Building Official as affording ventilation in accordance with standard ventilation requirements in the Mechanical Code.
(3) Bathroom light and ventilation. Every bathroom and toilet room shall comply with the light and ventilation requirements for habitable rooms contained in subsections (1) and (2), above, except that no window or skylight shall be required if such areas are equipped with a mechanical ventilation system which may be kept in continuous or timed operation. The ventilating system must move sufficient air to support a piece of toilet tissue on the fan's grate when the fan is in operation.
(4) Light and ventilation of public halls and stairways. Every public hall and stairway in every multiple dwelling shall be adequately lighted at all times. The lighting shall provide an intensity of .4 footcandle 1 foot above the walking surface.
The Planning and Development Services Unit will be responsible for approving individualized plans based on the individual needs of a particular dwelling for hallways which have an accumulation of odors, stuffiness, smoke accumulations, concentrations of chemicals and organic compounds, musty conditions or heat build-up.
(5) Screens. The ventilating area, as required by subsection (2) above, of each dwelling shall be adequately screened to permit ventilation and to prevent insect infestation. Such screens shall be applied no later than May 1 and removed no sooner than September 30 of each year. Where screen doors are provided or required on exterior doors, they shall be equipped with self closing devices. Each basement or cellar window required for ventilation shall be provided with screens. Other openings into a basement or cellar which might provide any entry for vermin shall be effectively closed or sealed.
(6) Exterior lighting of entrances. Beginning January 1, 1988 primary entrance of a dwelling shall be lighted as follows:
(a) Entrance lighting servicing up to and including 3 units shall be manually or automatically operated.
(b) Entrance lighting serving 4 or more units shall be automatically controlled so that lights will be operating from ½ hour after sunset until ½ hour before dawn. The light fixtures shall be in good repair, clean, mounted at a height of 5 to 10 feet, and have either a 60 watt incandescent or a 35 watt high pressure sodium lamp, or an equivalent that can provide a minimum level of 0.4 footcandles of illumination at any unobstructed point within 13 feet of the doorway. The illumination level shall be measured 3 feet above the surface.
Dwelling units with multiple entrances shall have at least 2 entrances lighted.