a. Multiple dwellings erected after nineteen hundred twenty-nine:
(1) Every apartment in a multiple dwelling erected after April eighteenth, nineteen hundred twenty-nine shall contain a water closet and a bath.
(2) In every such dwelling exceeding two stories in height, a water closet shall be accessible to every bedroom without passing through any other bedroom, and such access shall be required in every dwelling of two stories or less in height erected after July first, nineteen hundred sixty-one.
(3) In a multiple dwelling erected after July fourteenth, nineteen hundred sixty-seven, every apartment shall contain a washbasin.
b. Converted dwellings.
(1) Every apartment in a converted dwelling shall contain a water closet and a bath or shower; and every apartment in a dwelling converted after July first, nineteen hundred sixty-one shall also contain a washbasin.
(2) In an apartment located in a dwelling converted after April thirteenth, nineteen hundred forty, there shall be access to a water closet from every bedroom without passing through any other bedroom.
c. New law tenements.
(1) Every apartment in a new law tenement shall contain a water closet and a bath.
(2) In every apartment, a water closet shall be accessible to every bedroom without passing through any other bedroom.
d. Old law tenements.
(1) In every old law tenement a water closet shall be provided for the exclusive use of the occupants of every apartment. If it is not located within the apartment, the water closet shall be located on the same story as the apartment and shall be equipped with lock and key.
(2) Such water closet shall be constructed and ventilated as approved by the department.
e. New apartments in converted dwellings or tenements. After December ninth, nineteen hundred fifty-five, in any converted dwelling or tenement in which:
(1) the number of apartments in the dwelling is increased by any alteration, including the subdivision of existing apartments, the conversion of non-residential space or rooming units to apartments, or the enlargement of the dwelling; or
(2) all apartments in the dwelling are vacated by the department or, except in a summer resort dwelling, are untenanted for sixty days or more; a new certificate of occupancy shall not be issued and a newly created apartment shall not be occupied, or a vacated apartment reoccupied, unless it contains a water closet, bath or shower, and washbasin.
f. Requirements for all apartments in multiple dwellings effective January first, nineteen hundred seventy-three: Effective January first, nineteen hundred seventy-three, there shall be provided for the exclusive use of the occupants of each apartment in a multiple dwelling a water closet, a bath or shower; and a wash basin, except that in tenements, no wash basin shall be required pursuant to this section where there is a sink within the apartment.