Section 28-118.3.4. Existing buildings or open lots without certificates of occupancy

A building or open lot in existence prior to January 1,  1938  and  heretofore  legally  used  or  occupied  without  a  certificate of
  occupancy or, if applicable, a certificate of completion, and subject to
  the provisions of section  28-102.4  (continuation  of  lawful  existing
  use),  may  continue  to  be  used  or occupied without a certificate of
  occupancy or, if applicable, a certificate of  completion,  pursuant  to
  the  requirements of section six hundred forty five of the New York city
  charter, this code and other applicable laws and rules provided there is
  no change in  the  existing  use  or  occupancy  classification  of  the
  building, open lot or portion thereof.