No yard, buffer strip or other open space, off-street parking space or loading berth, or lot existing on the effective date hereof shall be reduced in dimension or area below the requirements set forth hereinafter. Yards, buffer strips or other open spaces, off-street parking spaces or loading berths, or lots created or established after the effective date hereof shall meet at least the minimum requirements established by this chapter.
(1977 Code, § 5-3-9)