The purpose of this chapter is to provide for the regulation of nonconforming uses, buildings and structures and to specify those circumstances and conditions under which those nonconforming buildings, structures and uses shall be eliminated. It is the intent of this title that nonconforming buildings, structures and uses shall not be enlarged upon, expanded or extended nor be used as grounds for adding other structures or uses prohibited elsewhere in the same district except as otherwise specifically permitted herein. (1965 Code title 6 § 501.0)