If two (2) or more lots, or a combination of lots or portion of lots with contiguous frontage in single ownership are of record at the time of passage or amendment of this Ordinance, and if all or part of these do not meet the requirements established for lot width and area, the lands involved shall be considered to be an undivided parcel for the purposes of this Ordinance. No portion of said parcel shall be used or sold in a manner which diminishes compliance with lot width and area requirements established by this Ordinance.