New York Laws
Title 1 - Light and Air
30 - Lighting and Ventilation of Rooms.

(b) All required windows shall be so constructed that at least
one-half of their required area may be opened, except that a mullioned
casement window, if otherwise large enough to supply the window
requirements of the room, need be readily openable to the outer air only
to the extent of five and one-half square feet of its area.
(c) Where fresh air is furnished in any room through a mechanical
ventilating unit or system which is an integral part of the dwelling
structure and capable of introducing not less than forty cubic feet of
air per minute, the required window area in such room need be openable
only to the extent of twenty-five per cent of such window area but in no
event less than five and one-half square feet.
9. Transoms or partition sash, or louvres having a minimum area of 144
square inches and arranged to be opened or closed, shall be provided to
private halls or to adjoining rooms to secure through-ventilation
whenever required by the department, but no such transom or partition
sash or louvre shall be required in a room having two windows opening to
the outer air if each window is at least nine square feet in area, or in
a room having a mullioned or single window with an aggregate area of at
least eighteen square feet.
10. All windows and their assemblies in walls situated on a lot line,
except those facing on a street, shall be fireproof, with assemblies
having a fire-resistive rating of at least three-quarters of an hour and
glazed with wire glass at least one-quarter of an inch thick. Every
opening in a wall situated on a lot line which is less than fifty feet
in a vertical direction above a non-fireproof roof of another structure
within a distance of thirty feet of the wall in which the opening is
located shall be an automatic fireproof window.