1. Every shaft constructed after April eighteenth, nineteen hundred twenty-nine, in any multiple dwelling shall be enclosed on all sides with fireproof walls and shall have fireproof doors and assemblies at all openings, with the doors self-closing. Dumbwaiter shafts, except those adjoining public halls, may be constructed with walls of gypsum plaster blocks approved by the department, at least two inches thick if solid and at least three inches thick if hollow.
2. All dumbwaiter doors constructed after such date shall be fastened by an interior lock in the shaft operated and controlled from a central point in the cellar or lowest story if there be no cellar.
3. The doors of every elevator shaft constructed after such date shall be provided with an automatic device approved by the department to prevent the normal operation of the elevator unless the hoistway door at which the car is standing is closed and locked, or unless all hoistway doors are locked in a closed position. Such doors may have a vision panel of wire glass not exceeding one square foot in area.
4. Every elevator installed after such date shall be equipped with a gate with an automatic device approved by the department to prevent the normal operation of such elevator unless such gate is closed.
5. When any elevator or dumbwaiter constructed after such date opens into more than one stair, elevator vestibule or other public hall on any floor, such elevator or dumbwaiter shall be placed in a separate shaft. Not more than three elevators or two dumbwaiters shall ever be placed in the same shaft.
6. Every dwelling erected after such date which exceeds six stories or sixty feet in height shall be equipped with one or more passenger elevators, operative at all times, at least one of which shall be accessible to every apartment above the entrance story.
7. In every multiple dwelling, elevator shafts, not previously enclosed to the satisfaction of the department, shall be enclosed with fireproof walls and shall have fireproof doors and assemblies, with the doors self-closing.