§ 171. Water-closet and bath accommodations. 1. Every dwelling
arranged for permanent occupancy shall contain a water-closet in every
apartment.

2. The floor of every compartment, bathroom or general toilet room
shall be made waterproof and such waterproofing shall extend six inches
or more above the floor so that the floor can be washed or flushed out
without leaking. No plumbing or plumbing fixture shall be enclosed
wholly or in part with woodwork.

3. Water-closets may be placed together in a general toilet room
provided such water-closets are supplementary to the water-closet
accommodations required for the exclusive use of tenants of the
dwelling, or are solely for the use of business portions of the
dwelling.

4. Every apartment arranged for permanent occupancy shall contain a
bath or shower accessible from every bedroom without passing through any
other bedroom. In dwellings arranged for transient occupancy there shall
be at least one shower or bath for every eight resident occupants.

5. Except as specifically provided otherwise in this chapter, every
water-closet compartment and bath or shower room shall have a window
opening upon a street or upon a lawful court or yard.

6. In lieu of a required window or skylight, it shall be lawful to
install a system of mechanical or gravity ventilation for water-closet
compartments or bathrooms in any portion of a dwelling. Such system of
ventilation shall be constructed, arranged and maintained continuously
to provide at least four changes per hour of the air volume of each such
water-closet compartment or bathroom.