13 - Application of chapter to existing dwellings.

§  13.  Application  of  chapter  to  existing dwellings. Any building  erected and occupied on or before  April  eighteenth,  nineteen  hundred  twenty-nine, or thereafter, as a tenement, which is not recorded as such  in  the  department, shall be required to comply with all the provisions  governing dwellings of like class  or  kind  erected  after  such  date.  Except  as  otherwise expressly required in this section and in sections  nine  and  twenty-five,  subdivision  six  of  section  thirty-one,  and  sections thirty-three, sixty-six and sixty-seven and in articles six and  seven,  nothing in this chapter shall be construed to require any change  in the construction, use or occupancy of any multiple dwelling  lawfully  occupied  as  such  on  April  eighteenth, nineteen hundred twenty-nine,  under  the  provisions  of  all  local  laws,  ordinances,   rules   and  regulations applicable thereto on such date; but should the occupancy of  any such dwelling be changed to any other kind or class after such date,  such dwelling shall be required to comply with the provisions of section  nine.