Where uncertainty exists with respect to the boundaries of the various districts as shown on the Official Zoning Map and made a part of this chapter, the following rules apply:

1.   Streets and Alleys Used For District Lines. The district boundaries are either streets or alleys unless otherwise shown, and where the districts designated on the Official Zoning Map accompanying and made a part of this chapter are bounded approximately by street or alley lines.

2.   Lot Lines Used For District Lines. Where the district boundaries are not otherwise indicated, and where the property has been or may hereafter be divided into blocks and lots, the district boundaries shall be construed to be the lot lines, and where the districts designated on the Official Zoning Map are bounded approximately by lot lines, unless the boundaries are otherwise indicated on the map.