If two (2) or more adjoining and vacant platted lots with continuous frontage are in a single ownership at any time after the adoption date hereof, and such platted lots individually are too small to meet the yard dimensions and area requirements of the district in which they are located, such group of platted lots shall be considered a single plot, or several plots of minimum size, and the plot or plots in one ownership shall be subject to the requirements of this title and all sections thereof. (Ord. 1000 § 49.00, 1955)