2006 New York Code - Maximum Permitted Occupancy.

 
    §  27-2075  Maximum  permitted occupancy. a. No dwelling unit shall be
  occupied by a greater number  of  persons  than  is  permitted  by  this
  section.
    (1)  Every  person  occupying  an  apartment  in  a class A or class B
  multiple dwelling or  in  a  tenant-occupied  apartment  in  a  one-  or
  two-family  dwelling  shall  have a livable area of not less than eighty
  square feet.  The maximum number of persons  who  may  occupy  any  such
  apartment  shall  be determined by dividing the total livable floor area
  of the apartment by eighty square feet. For every two  persons  who  may
  lawfully  occupy  an  apartment,  one  child  under four may also reside
  therein, except that a child under four is  permitted  in  an  apartment
  lawfully  occupied  by  one  person. No residual floor area of less than
  eighty square feet shall be counted in determining the maximum permitted
  occupancy for such apartment. The floor area of a kitchen or kitchenette
  shall be included in measuring the  total  liveable  floor  area  of  an
  apartment  but  the  floor  area for private halls, foyers, bathrooms or
  water closets shall be excluded.
    (2) A living room in a rooming unit may be occupied by not  more  than
  two persons if it has a minimum floor area not less than one hundred ten
  square  feet  in a rooming house, or one hundred thirty square feet in a
  single room occupancy.
    b. The maximum number of persons who may occupy a dormitory shall  not
  exceed  the  occupancy permitted under section sixty-six of the multiple
  dwelling law, and the regulations issued thereunder by the department.
    c. On written demand by the department, or by the owner when he or she
  rents a dwelling unit or any time thereafter, the tenant shall submit an
  affidavit setting forth the names  and  relationship  of  all  occupants
  residing  within  the  dwelling  unit and the ages of any minors. In the
  event of an increase in the number of occupants, the tenant shall advise
  the owner and, if the owner so demands  in  writing,  the  tenant  shall
  submit  an  affidavit, setting forth the pertinent information regarding
  such increase in occupancy.
    d. In any case where the birth of a child or its attainment of the age
  of four causes the number of persons or children to exceed  the  maximum
  occupancy  permitted  in  this  section,  such excess occupancy shall be
  permissible until one year after such event.
    e. In every rooming unit, a sign shall be posted showing  the  maximum
  lawful  occupancy.  Such  sign shall be made and installed in the manner
  and location prescribed by the department and shall be maintained at all
  times.