§ 274. Fire-escapes erected before October first, nineteen hundred and thirteen. All outside fire-escapes erected before October first, nineteen hundred and thirteen, and serving as required exits under the provisions of section two hundred and seventy-one shall conform to the following requirements:

1. There shall be balconies on each floor of the building connected with stairways placed at an angle of not more than sixty degrees.

2. A stairway shall lead from the top floor balcony to the roof, except when the fire-escapes are erected on the front of the building.

3. A stairway not less than twenty-two inches wide shall lead from the lowest balcony to a safe landing place beneath, which stairway shall remain down permanently or swing up and down by counterbalancing weights.

4. A safe and unobstructed exit shall be provided to the street from the foot of such fire-escapes as required in subdivision nine of section two hundred and seventy-three.

5. Steps shall connect the sill of every opening leading to the fire-escapes with the floor wherever such sill is more than three feet above the floor level.

6. All openings leading to the fire-escapes shall be provided with fireproof windows or fire doors.

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