53 Pa. Stat. § 24936
There shall be balconies not less than four feet in width in the said open court or courts at each level or tier above the parquet on each side of the auditorium, of sufficient length to embrace the two exits; and from said balconies there shall be staircases extending to the ground level with a rise of not over eight and one-half inches to a step and not less than nine inches tread, exclusive of the nosing. The staircase from the upper balcony to the next below shall not be less than thirty inches in width in the clear, and from the first balcony to the ground three feet in width in the clear where the seating capacity of the auditorium is for one thousand people or less, three feet and six inches in the clear where above one thousand and not more than one thousand eight hundred people, and four feet in the clear where above one thousand eight hundred people and not more than two thousand five hundred people, and not less than four feet six inches in the clear where above two thousand five hundred people. All the said balconies and staircases shall be constructed of iron throughout, including the floors, and of ample strength to sustain the load to be carried by them, and they shall be covered with a metal hood or awning to be constructed as shall be directed by the bureau of building inspection. Where one side of the building borders on a street there shall be balconies and staircases of like capacity and kind as hereinbefore mentioned carried to the ground.
53 P.S. § 24936