Article 6 - STANDARDS OF NATURAL VENTILATION

Section 27-745

Section 27-745

  § 27-745 Occupiable rooms. All occupiable rooms shall be ventilated by
natural  or  mechanical  means,  or  by  a  combination of both. Natural
ventilation may be  provided  except  where  mechanical  ventilation  is
required by article seven or eight of this subchapter.

Section 27-746

Section 27-746

  §  27-746  Habitable rooms. All habitable rooms shall be provided with
natural ventilation complying with the  provisions  of  this  subchapter
except as provided in section 27-750 of this article.

Section 27-747

Section 27-747

  §  27-747 Alcoves. An alcove or room opening off another room or space
shall be considered as a separate room in determining  its  requirements
for  ventilation.  However,  for dwellings classified in occupancy group
J-3, where the opening between the alcove and the room or  space  is  at
least  eighty  percent of the area of the common wall and the floor area
of the alcove does not exceed twice the area of the opening, the  alcove
and  the  room  opening  into  the  alcove may be considered as a single
space.

Section 27-748

Section 27-748

  §  27-748  Balconies.  Where an interior balcony or mezzanine opens to
form part of another room or space, its area shall be added to the  area
of  the  room or space in which it is located to compute the ventilation
required for both spaces.

Section 27-749

Section 27-749

  §  27-749  Natural  ventilation  sources.  Natural  ventilation,  when
required, shall be provided  by  windows,  skylights,  monitors,  doors,
louvers,   jalousies,   or  other  similar  ventilating  openings.  Such
ventilating openings shall open to the sky or a  public  street,  space,
alley,  park, highway, or right of way, or upon a yard, court, plaza, or
space above a setback, where such yard, court, plaza, or space  above  a
setback  is located on the same lot and is of the dimensions required by
the applicable provisions of the zoning resolution.

Section 27-750

Section 27-750

  §  27-750  Area  of  ventilating openings. Ventilating openings in all
habitable rooms or spaces shall have a free openable area  of  at  least
five percent of the floor area of the room or space ventilated and where
there  is  an  enclosed  or  partially enclosed balcony or space above a
setback  complying  with  section  27-733  of  article  three  of   this
subchapter  the  ventilating openings shall have a free openable area of
at least five per cent of the combined  floor  area  of  such  room  and
portion  of the balcony or space directly adjoining and in front of such
room. Each required ventilating opening shall have  a  minimum  openable
area  of  six square feet. Where fresh air is furnished in any habitable
room or space by mechanical means supplying a minimum of forty  cfm  the
free  openable  area  of  the openings may be reduced to one-half of the
above requirements but not less than five and one-half  square  feet  in
aggregate.  In  all  occupiable  rooms or spaces, the free openable area
shall be used to calculate the index for ventilation (section 27-753  of
article  seven  of  this  subchapter), which shall determine the minimum
requirements for supplementary mechanical ventilation.

Section 27-751

Section 27-751

  §  27-751 Minimum dimensions of habitable rooms. Habitable rooms shall
have a minimum clear width of eight feet in any part;  a  minimum  clear
area  of  eighty square feet and a minimum clear ceiling height of eight
feet for the minimum area, except:
  (a) A room which complies with the requirements for natural light  and
ventilation and in addition has an opening of not less than sixty square
feet into an immediately adjoining room may have a minimum floor area of
seventy square feet and a least horizontal dimension of seven feet;
  (b)  A  dining  space  which  has legally required ventilation, and in
which the window has an area of at least one-eighth the  floor  area  of
such dining space;
  (c)  One-half  the  number  of  bedrooms in a dwelling unit containing
three or more bedrooms may have at  least  minimum  dimension  of  seven
feet;
  (d)  A  room in a class B multiple dwelling as defined in section four
of the multiple dwelling law which may have  a  minimum  floor  area  of
sixty square feet and a least horizontal dimension of six feet.