34 Pa. Code § 47.170
No foundry shall be located after November 1, 1915, in a cellar or basement unless both the ceiling is at least 14 feet in height, measured from the finished floor to the under side of the ceiling, and proper and adequate provisions are made for lighting and ventilation. In addition to these two requirements if the foundry is, or is intended to be, located entirely in the front part of the building, the ceiling shall be in every part at least 6 1/2 feet above the curb level of the street in front of the building; or, if the foundry is or is intended to be located entirely in the rear part of the building or to extend from the front to the rear the ceiling shall be not less than 3 feet above the curb level of the street in front of the building and the foundry shall open upon a yard or court which shall extend 6 inches below its floor level.
34 Pa. Code § 47.170
This section cited in 34 Pa. Code § 47.171 (relating to existing cellar and basement foundries).