§ 273. Fire-escapes erected after October first, nineteen hundred and
thirteen, on buildings theretofore erected. All outside fire-escapes
erected after October first, nineteen hundred and thirteen, on buildings
theretofore erected and serving as required exits shall conform to the
following requirements:

1. They shall be built of wrought iron or steel and shall be so
designed, constructed and erected as to safely sustain on all platforms,
balconies and stairways a live load of not less than ninety pounds per
square foot with a factor of safety of four.

2. Whenever practicable a continuous run or straight run stairway
shall be built.

3. All openings leading thereto shall have an unobstructed width of at
least two feet and an unobstructed height of at least six feet. Such
openings shall extend to the floor level or within six inches thereof,
shall be not more than seven inches above the floor of the fire-escape
balcony and shall be provided with fire doors, except in buildings five
stories or under in height complying with the provisions of subdivisions
five and six of section two hundred and seventy-four.

4. All windows opening upon the course of the fire-escape shall be
fireproof windows.

5. On every floor above the first there shall be a balcony firmly
fastened to the building and embracing one or more easily accessible and
unobstructed openings. The balconies shall have a width of at least four
feet throughout their length and shall have a landing not less than
twenty-four inches square at the head of every stairway. There shall be
a passageway between the stairway opening and the side of the building
at least eighteen inches wide throughout except where the stairways
reach and leave the balconies at the ends or where double run stairways
are used. The stairway openings of the balconies shall be of a size
sufficient to provide clear headway and shall be guarded on the long
side by an iron railing not less than three feet in height. Each balcony
shall be surrounded by an iron railing not less than three feet in
height properly braced.

6. The balconies shall be connected by stairways not less than
twenty-two inches wide placed at an incline of not more than forty-five
degrees, with steps of not less than eight-inch tread and not over
eight-inch rise and provided with a handrail not less than three feet
above the treads. The treads of such stairways shall be so constructed
as to sustain a live load of four hundred pounds per step with a factor
of safety of four.

7. There shall be a similar stairway from the top floor balcony to the
roof, except where the fire-escape is erected on the front of the
building.

8. A similar stairway shall also be provided from the lowest balcony
to a safe landing place beneath, which stairway shall remain down
permanently or be arranged to swing up and down automatically by
counter-balancing weights.

9. When not erected on the front of the building, safe and
unobstructed egress shall be provided from the foot of the fire-escape
by means of an open court or courts or a fireproof passageway having an
unobstructed width of at least three feet throughout, leading to the
street, or by means of an open area having communication with the
street. Such fireproof passageway shall be adequately lighted at all
times and the lights shall be so arranged as to insure their reliable
operation when through accident or other cause the regular factory
lighting is extinguished.