No building or structure shall hereafter be erected, reconstructed, altered, restored or demolished within the historic district unless or until an application for a building or demolition permit shall have been approved as to exterior architectural features which are subject to public view from a public street, way or place. Evidence of such required approval shall be a certificate of appropriateness issued by the planning board.

Within the historic district zone buffer area, no new construction shall hereafter be erected, and no demolition shall hereafter be undertaken, unless or until an application for a building or demolition permit shall have been approved as to its exterior architectural features. Evidence of such required approval shall be a certificate of appropriateness issued by the planning board.