Mich. Comp. Laws § 125.492
Privy vaults, school-sinks and water-closets. Whenever a connection with a sewer is possible, all privy vaults, school-sinks, cesspools or other receptacles used to receive fecal matter, urine or sewage, shall with their contents, be completely removed and the place where they were located properly disinfected under the direction of the health officer. Such appliances shall be replaced by individual water-closets of durable non-absorbent material, properly sewer-connected, and with individual traps and properly connected flush tanks providing an ample flush of water to thoroughly cleanse the bowl. Each such water-closet shall be located inside the dwelling or other building in connection with which it is to be used in a compartment completely separated from every other water-closet, and such compartment shall contain a window of not less than 4 square feet in area opening directly to the street, or rear yard or on a side yard or court of the minimum sizes prescribed in sections 13 and 14 of this act. The floors of the water-closet compartments shall be as provided in section 35 of this act. Such water-closets shall be provided in such numbers as required by section 67 of this act. Such water-closets and all plumbing in connection therewith shall be sanitary in every respect and, except as in this act otherwise provided, shall be in accordance with the local ordinances and regulations in relation to plumbing and drainage. Pan plunger, frostproof and long hopper closets will not be permitted except upon written permit of the health officer, or such other appropriate public official as the mayor may designate. No water-closet shall be placed out of doors.
MCL 125.492