2006 New York Code - Alterations To Multiple Dwelling And Conversions To Multiple Dwellings.

 
    §  27-120 Alterations to multiple dwelling and conversions to multiple
  dwellings. At the option of the owner, regardless of  the  cost  of  the
  alteration  or  conversion,  an  alteration  may  be  made to a multiple
  dwelling or a building may  be  converted  to  a  multiple  dwelling  in
  accordance  with all requirements of this code or in accordance with all
  applicable laws in existence prior to December sixth,  nineteen  hundred
  sixty-eight,  provided  the  general  safety  and public welfare are not
  thereby endangered.