2006 New York Code - Natural Light Sources And Location.

 
    §  27-733  Natural light sources and location. (a) Natural light, when
  required, shall be provided  by  windows,  skylights,  monitors,  glazed
  doors,   transoms,   fixed  lights,  jalousies  or  other  natural-light
  transmitting media. Such sources shall not be located in recesses having
  a width of less than six feet, and such sources shall not be located  so
  as to create a habitable room whose depth exceeds thirty feet, except in
  dwelling  units  of  group  one  construction containing more than three
  habitable rooms. Such sources, except as provided in subdivision (b)  of
  this  section,  shall face or open upon the sky or upon a public street,
  space, alley, park, highway, or right of way, or  upon  a  yard,  court,
  plaza,  or space above a setback, when such yard, court, plaza, or space
  above a setback is located upon the same lot and is  of  the  dimensions
  required  by  the  applicable provisions of the zoning resolution. Where
  dwelling units in buildings or spaces classified in occupancy group  J-1
  or J-2 are located in a cellar or a basement such dwelling unit or units
  shall  have  at  least  one-half of their height and all of their window
  surfaces  above  every  part  of  an  "adequate  adjacent  space".  Such
  "adequate  adjacent  space"  shall  be  open  to  the sky and shall be a
  continuous surface area outside the dwelling unit or units not less than
  thirty feet in its  least  dimension  and  abutting  at  same  level  or
  directly below every part of the exterior walls of such dwelling unit or
  units.  Such  "adequate  adjacent space" shall include only spaces which
  are located on the same lot or plot as  the  building  or  on  a  public
  street,  space,  alley,  park,  highway or right of way and the level of
  such areas which abut or adjoin the habitable room at least shall be six
  inches below the window sills of any windows.
    (b) Natural light sources  may  face  or  open  upon  an  enclosed  or
  partially enclosed balcony or space above a setback when such balcony or
  space  faces  upon a public street, space, alley, park, highway or right
  of way or upon a yard, court, plaza, or space above a setback, when such
  yard, court, plaza, or space above a setback is located  upon  the  same
  lot  and is of the same dimensions required by the applicable provisions
  of the zoning resolution, the maximum depth of any habitable room is  at
  most  thirty  feet  measured from the outer face of the wall forming the
  partial or full enclosure of the balcony or space, the enclosure of  the
  balcony  or  space is not more than one story in height, and the balcony
  or space complies with either of the following:
    (1) The front of the balcony or space above a setback has  an  opening
  to the outer air whose area is equal to at least seventy-five percent of
  the floor surface area of such balcony or space.
    (2)  The  front  of  the  balcony  or  space  above  a  setback may be
  completely enclosed when the  building  is  of  group  one  construction
  provided  the outer enclosing walls are glazed with clear plate glass or
  with plastic equivalent complying with subdivision (e) of section 27-331
  of article four of subchapter five of this chapter and such glazed  wall
  area  is equal to at least fifty percent of the interior walls enclosing
  such balcony or space and at least fifty percent of the required  glazed
  area   is   openable  and  no  window  from  any  bathroom,  watercloset
  compartment, or kitchen whose area is fifty-nine  square  feet  or  less
  opens on such balcony or space.