Pennsylvania Statutes Title 53 P.S. Municipal and Quasi-Municipal Corporations § 24903. Thickness of stone party walls

No party wall where built of stone shall be less than sixteen inches in thickness:  Provided, That when an application is made for a permit to erect an additional story upon a one or two-story building used, or to be used for a dwelling, and the party walls of the said building are but nine inches thick, the bureau of building inspection may, in its judgment, issue such permit without requiring any additional thickness for the party wall.