The maximum permitted height of fences, walls and hedges, except as otherwise provided in Sections 17.52.420 and 17.52.440 shall be as follows:

    A.    When located in a required yard on a corner lot and within thirty (30) feet of the intersection of the street lot lines or of the projections of such lines: two feet, measured upward from the center line grade of the street opposite thereto;

    B.    When located in a required rear or street side yard of a corner lot and within twenty (20) feet of the corner common to such a lot and a key lot at the rear: four feet;

    C.    When located in a required front yard other than as specified in subsection A of this section: four feet;

    D.    When located in any A or R district other than as specified hereinabove six feet;

    E.    When located in any C or M district and within five feet of the boundary of any A or R district: six feet high. (Prior gen. code § 8-60.55)