These provisions shall apply to all buildings or structures
and all uses of buildings or structures or lots lawfully existing
prior to the effective date of this chapter or of subsequent amendments,
revisions or reenactments of such chapter which do not conform to
the provisions of said original chapter or to such revisions or reenactments
on their effective dates.
No unlawful building or structure or unlawful use of a building
or structure or lot existing at the effective date of this chapter
shall be deemed to be a nonconforming building, structure or use.
A nonconforming use shall not be enlarged or extended, except as provided in §
170-56B.