Article 3 - STANDARDS OF NATURAL LIGHT

Section 27-732

Section 27-732

  §  27-732  Natural  light  requirements. Every habitable room shall be
provided with natural  light  complying  with  the  provisions  of  this
subchapter.

Section 27-733

Section 27-733

  §  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.

Section 27-734

Section 27-734

  §  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.