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
§ 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
§ 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
§ 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
§ 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
§ 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
§ 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.