Within the districts established by this chapter or amendments that may later be adopted, there exist lots, structures, uses of land and structures and characteristics of use which were lawful before November 20, 1975, or before the date of adoption of any such applicable amendment, but which would be prohibited, regulated or restricted under the terms of this chapter or such future amendments. It is the intent of this article to permit these nonconformity’s to continue until they are removed but not to encourage their survival. It is further the intent of this article that non-conformities 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.