Section 27-734. Area of natural light sources

Required sources of natural
  light shall have an aggregate transmitting area of at least ten  percent
  of  the  floor area of the room or space served and where an enclosed or
  partially enclosed balcony or  space  above  a  setback  complying  with
  section  27-733  of  this  article  intervenes,  the required sources of
  natural light shall have an aggregate transmitting area of at least  ten
  percent  of  the combined floor area of such room and the portion of the
  balcony or space directly adjoining and in  front  of  such  room.  Each
  required  source shall have a minimum transmitting area of twelve square
  feet and only that area of the light source above thirty inches from the
  finished floor may be considered as providing the natural light required
  in any space.