Where uncertainty exists as to the locations of any boundaries shown on the Zoning Map, the following rules shall apply:
(a) District boundary lines are intended to follow streets, rights of way, watercourses or lot lines or be parallel or perpendicular thereto, unless such district boundary lines are fixed by dimensions as shown on the Zoning Map.
(b) Where district boundaries are indicated as approximately following streets, rights of way or watercourses, the centerlines thereof shall be construed to be such boundaries.
(c) Where district boundaries are so indicated that they approximately follow lot lines, such lot lines shall be construed to be such boundaries.
(d) If, after use of the rules above and the Zoning Map, the district classification of any land is in question, it shall be deemed to be in the most restrictive of the adjoining districts.
(e) Where a district boundary line divides a lot which was in single ownership at the time of the passage of this Zoning Ordinance, the Board of Zoning Appeals may permit, as a special exception, the extension of the regulations for either portion of the lot, not to exceed twenty-five feet beyond the district line into the remaining portion of the lot.
(1970 Code Sec. 32-9)