§ 236. Stairs in fireproof tenements. 1. Except as in this section otherwise provided, every fireproof tenement erected after May fifteenth, nineteen hundred two, containing more than thirty-six apartments or suites of rooms above the entrance story shall have an additional stair for every additional thirty-six apartments or suites or fraction thereof.

2. If such a tenement contains not more than forty-eight apartments or suites above the entrance story, in lieu of an additional stair the stairs, stair halls and entrance halls throughout the entire tenement may each be at least one-half wider than is specified in sections two hundred thirty-four, two hundred thirty-seven and two hundred thirty-eight.

3. If such a tenement contains more than seventy-two apartments or suites but not more than eighty-four above the entrance story, in lieu of three stairs there may be only two stairs, provided that one of such stairs and the stair and entrance halls connected therewith are at least one-half wider than is specified in sections two hundred thirty-four, two hundred thirty-seven and two hundred thirty-eight.

4. For the purposes of this section a janitor's apartment in a penthouse shall not be construed as an additional apartment.

5. The number of apartments on any story in any fireproof tenement may be altered, if the number of living rooms on such story is not increased by more than thirty per centum. If the number of living rooms on any story or section thereof above the entrance story exceeds thirty, there shall be an additional stair for each thirty rooms or fraction thereof on any such story or section thereof, except that if the number of living rooms on any such story or section does not exceed forty, in lieu of an additional stair one stair and every public hall connected therewith may be at least one-half wider than is specified in sections two hundred thirty-four, two hundred thirty-seven and two hundred thirty-eight; but in every such tenement erected before May sixteenth, nineteen hundred thirteen, and altered as herein permitted, the occupants of each additional apartment shall have access to at least two independent means of egress, which shall be made to conform to the requirements of section two hundred thirty-one for fireproof tenements erected after such date.

6. Whenever the total number of rooms, exclusive of bathrooms, water-closet compartments, and cooking spaces less than eighty square feet in area, in any fireproof tenement or section thereof is decreased through the process of an alteration, the number of apartments may be altered and the provisions of this section which relate to additional stairs shall not be applicable.