Every new dwelling house shall have at least fourteen feet front: Provided, however, That this limitation shall not apply to lots of less than fourteen feet in width on which buildings are now erected, nor to lots less than fourteen feet in width which are bounded on each side by ground belonging to other owners at the time of the approval of this act; and every such new dwelling house shall have an open space attached to it in the rear or at the side, equal to at least one hundred and forty-four square feet clear space, unobstructed by any overhanging structure.
53 P.S. § 24905