Section 140. Application of article five

The provisions of this article
  shall apply to non-fireproof  multiple  dwellings  erected  after  April
  eighteenth,  nineteen  hundred  twenty-nine, and to such dwellings only.
  They shall apply  to  all  such  non-fireproof  dwellings  unless  their
  application  is  expressly  limited  to dwellings of a particular class.
  They shall apply in addition  to,  and  not  in  substitution  for,  the
  provisions  of  article  three.  However  the provisions of this article
  shall not apply to a multiple dwelling three stories or less  in  height
  to  be  occupied  by not more than three families in all, with a maximum
  occupancy of two families on each floor in a two story building and  one
  family  on  each  floor in a three story building, provided however that
  all the provisions of article six are complied with,  including  section
  one hundred seventy-a of said article.