In any residential zone, no fence shall be permitted in the front yard area which will restrict visibility and be over four (4) feet high. No fence shall exceed six (6) feet in height. On a corner lot, the fencing along the street frontage coincident with the architectural front door, or main dwelling entrance, shall be subject to the same restrictions as for a front yard area. On a corner lot, the fencing along the street frontage not coincident with the architectural front door, or main dwelling entrance, shall be permitted to extend into the front yard setback area for a distance equal to one-half (1/2) of the required front yard setback distance. On a through lot, the fencing along both street frontages shall be subject to the same restrictions as for a front yard area. For the purposes of this section, a "through lot" shall be defined as: an interior lot which fronts upon two (2) streets which do not intersect at the boundaries of the lot, and which runs unobstructed from one street to another. A corner lot shall not be considered a through lot.