On through lots, either lot line separating such lot from a public thoroughfare may be designated by the owner as the front line. In such cases, the minimum rear yard shall be the average of the yards on lots next adjoining. If such lots next adjoining are undeveloped, the minimum rear yard shall conform to the front yard setback for the zone in which the property is located.
('61 Code, § 10-3.410) (Ord. 231 N.S., passed - - )