1. Except as otherwise specifically provided in subdivisions three and four and in paragraphs b to j inclusive of subdivision six, every multiple dwelling which exceeds two stories in height shall have at least two fire-stairs. Such fire-stairs shall extend from the entrance story to the roof and be equipped with fireproof self-closing doors glazed with wire glass and without transoms. No windows shall be required in such stairs, but any openings in exterior walls, except any window openings facing a street or yard, shall be equipped with fireproof frame and sash glazed with wire glass. Entrances to such fire-stairs shall be at least fifteen feet distant from each other and from the entrance to every other fire-stair or fire-tower, except that the distance between two such entrances may be less if they are on opposite sides of an elevator vestibule or other public hall or are separated by an elevator shaft. The doors giving access to such stairs shall not be held open by any device whatever.2. Every such fire-stair shall have an entrance on the entrance story from a street or an entrance at the side or rear of the dwelling from a yard, court or passageway having continuous, safe and unobstructed access to a street. Except as otherwise expressly provided in paragraphs b to j inclusive of subdivision six, in a dwelling not exceeding one hundred twenty-five feet in height every stair, fire-stair and fire-tower shall be at least three feet in clear width, and where only one fire-stair or fire-tower is required such fire-stair or fire-tower shall be at least three feet eight inches in clear width. In a dwelling exceeding one hundred twenty-five feet in height every required fire-stair shall be at least three feet eight inches in clear width from the entrance story up to a floor level not more than one hundred feet below the ceiling of the highest story, and above such level every fire-stair shall be at least three feet in clear width. Every stair landing at every floor level shall be at least three feet eight inches in clear width in every direction.3. Except in dwellings erected under plans filed with the department before April twenty-eighth, nineteen hundred thirty, and except as otherwise provided in paragraphs b to j inclusive of subdivision six there shall be horizontal access from every apartment to at least two fire-stairs, at least one of which shall be within seventy-five feet horizontally in the line of travel from a required means of egress from such apartment.4. Except as provided in paragraphs b, c and d of subdivision six, a fire-tower may be substituted for any required fire-stair. When a fire-tower is substituted for a fire-stair, such fire-tower shall comply with all the applicable requirements for the fire-stair it replaces and shall have its means of egress directly to a street or to a yard or court having direct, unobstructed access to a street without passing through any entrance hall; except that a fire-tower may have its means of egress into a public vestibule if such means is not more than fifteen feet from a street in the line of travel.5. The stairs in a tower or dwelling containing a passenger elevator and meeting the conditions of paragraphs f, g or h of subdivision six may conform to the provisions of such paragraph and paragraph i of such subdivision in lieu of the different provisions which would otherwise be applicable thereto.6. Under the special conditions described in paragraphs a to j inclusive and in the following table, which applies only to class A dwellings, stairs shall conform to the applicable provisions of such paragraphs and table.NOTE: TABLE FOUND IN CHAP. 234 OF THE LAWS OF 1964
a. Except as otherwise expressly provided in this paragraph and in paragraphs b to j inclusive of subdivision six, if the number of living rooms on any story above the entrance story exceeds forty, there shall be an additional fire-stair for each twenty living rooms or fraction thereof in excess of forty on any story above the entrance story. Such an additional fire-stair shall not be required if the number of living rooms on no story above the entrance story exceeds fifty and in addition the clear width of one fire-stair is at least one and one-half times the width specified for a fire-stair in subdivision two, the clear width of every public hall connected with such fire-stair is at least one and one-half times the width specified for a public hall in section one hundred seven and the clear width of every entrance hall connected with such fire-stair is at least one and one-half times the width specified for an entrance hall in section fifty. Any additional fire-stair constructed pursuant to this paragraph need not be carried to a greater height than the level of a roof, or of a terrace formed by a setback, above the highest story on which the number of rooms requires such additional stair. When any fire-stair terminates at the level of a setback of any outer wall, such setback shall form a terrace at least four feet in depth measured between the inside of the parapet wall and the wall of the dwelling and at least ten feet in length measured parallel to the wall of the dwelling.b. In a class A dwelling or section thereof not exceeding six stories in height, for which plans shall have been filed in the department before September first, nineteen hundred fifty-one, only one stair shall be required, provided the number of apartments having access to such stair on each story does not exceed six and the aggregate number of living rooms in such apartments does not exceed twenty, except that the total number of rooms above the first story shall not exceed one hundred and the total number of apartments above the first story shall not exceed thirty. Such stair shall in addition comply with all the provisions of section one hundred forty-eight relating to stairs in non-fireproof dwellings, except that in lieu of a window such stair may have at each story an opening to a street or to a lawful yard or court other than a court on a lot line. Such opening shall be at least forty square feet in area and five feet in width, and shall be furnished with a properly secured guard railing at least five feet in height and approved by the department. Such opening shall be kept continuously open to the outer air. No means of egress from any apartment to such stair shall be more than twenty-five feet distant therefrom.c. In a class A dwelling or section thereof not exceeding six stories in height only one stair shall be required, provided the number of living rooms on any story above the entrance story does not exceed twenty. If the number of living rooms on any story or section thereof above the entrance story exceeds twenty, there shall be an additional stair for each twenty rooms or fraction thereof on any such floor or section in excess of twenty, except that if the number of living rooms on no such story or section above the entrance story exceeds thirty, in lieu of an additional stair one stair and every public hall connected therewith may be four feet six inches in clear width. Such stair shall be completely separated from every other stair, fire-stair, fire-tower, public hall and shaft by fireproof walls. Doors to stairs, fire-stairs and fire-tower balconies from any public hall in such a dwelling or section shall be at least three feet wide, self-closing and fireproof, with their assemblies also fireproof. The panels of every such door shall be glazed with clear wire glass and no pane thereof shall exceed three hundred sixty square inches in area. Those portions of the enclosure partition which separate the public hall from the stair shall be glazed with wired plate glass at least one-quarter inch in thickness, with no pane more than three hundred sixty square inches in area, so as to provide so far as practicable an unobstructed view of the stair from each public hall. Glass panels shall be at least twelve inches and not more than sixteen inches above the floor of the public hall. Public halls providing access to any such enclosed stair shall be lighted and ventilated as prescribed for non-fireproof dwellings in section one hundred forty-nine. No means of egress from any apartment to such a stair shall be more than fifty feet distant therefrom.d. In a class A dwelling or section thereof not exceeding six stories in height only one stair shall be required, provided the number of apartments having access to such stair at each story does not exceed eight and the aggregate number of living rooms in such apartments does not exceed twenty-five, except that the total number of living rooms above the first story shall not exceed one hundred twenty-five and the total number of apartments above the first story shall not exceed forty. No means of egress from any apartment to such stair shall be more than twenty-five feet distant therefrom. Doors and stair enclosures shall conform to the provisions of paragraph c.e. In a dwelling conforming to the provisions of paragraph b, c or d the lowest story may be designated as a basement if such story is not used for living purposes but is used solely for storage or other general utility purposes accessory to the occupancy, use and management of the dwelling. Such a basement shall not be deemed a story in computing the height of the dwelling.f. Every tower erected pursuant to plans on or after December fifteenth, nineteen hundred sixty-one in a fireproof dwelling shall be provided with at least one passenger elevator. Such elevator shall be operated between the ground story and the highest story of such tower containing any living room and horizontal access thereto shall be provided at each story for every apartment in the tower. Stairs in such a tower may comply with the following provisions of this paragraph in lieu of the different provisions otherwise applicable. In such case there shall be provided at least one fire-stair. If there are more than fifteen living rooms on any story of the tower, there shall be an additional fire-stair for each additional fifteen such rooms or fraction thereof. Every fire-stair so required shall extend from the top story of the tower to the entrance hall of the dwelling and be horizontally accessible from each story of every apartment in the tower. If the tower was erected under plans filed with the department on or after April twenty-eighth, nineteen hundred thirty, it shall also have an additional means of egress as provided in paragraph i of this subdivision.g. In a dwelling in which one or more passenger elevators are operated with horizontal access from every apartment in the dwelling and in which every story has an area of not more than twenty-five hundred square feet exclusive of elevator shafts, public halls, stairs and fire-stairs and contains not more than fifteen living rooms, stairs may comply with the provisions of this paragraph in lieu of the different provisions otherwise applicable. In such case there shall be at least one fire-stair, and there need not be more than one, accessible from each apartment on each story and extending from the roof to the entrance story with unobstructed access to a street. If the dwelling was erected under plans filed with the department on or after April twenty-eighth, nineteen hundred thirty, it shall also have an additional means of egress as provided in paragraph i.h. When a dwelling is divided into sections by unpierced fireproof construction extending from the second tier of beams above the ground story to the roof, and one or more passenger elevators are operated in each such section with horizontal access from each apartment therein, and every story of each such section above the entrance story contains not more than ten living rooms where there are four or more apartments on such story or not more than fifteen living rooms where there are three apartments or less on such story, stairs may comply with the provisions of this paragraph in lieu of the different provisions otherwise applicable. In such case there shall be in each such section at least one fire-stair, and there need not be more than one, extending from the roof to the entrance story with unobstructed access to a street. If the dwelling was erected under plans filed with the department on or after April twenty-eighth, nineteen hundred thirty, each such section shall also have an additional means of egress as provided in paragraph i.i. The main means of egress from every apartment in a tower or dwelling erected pursuant to the provisions of paragraph f, g, or h shall be within twenty-five feet of a fire-stair meeting the requirements of such paragraph. If the tower or dwelling was erected under plans filed with the department on or after April twenty-eight, nineteen hundred thirty, egress shall also be provided, in addition to the required fire-stairs, by means of another stair extending from the main roof of the dwelling, or in the case of a tower from the highest story thereof, to the entrance story, with unobstructed access to a street. Such additional stair shall be horizontally accessible from each apartment at each story through a vestibule or other public hall and shall conform with all the requirements for a fire-stair except that its clear width may be reduced to a minimum of twenty-eight inches, its risers may be increased to a maximum of nine inches in height, and its treads, exclusive of nosing, may be reduced to a minimum of eight inches in width. No door giving access thereto shall swing into such stair.j. A class B dwelling in which at least eighty per centum of the living rooms above the second story open directly upon a public hall without any intervening foyer or private hall, shall have at least two fire-stairs accessible at each story from each room through a public hall. Such fire-stairs shall be so located that at least one fire-stair shall be not more than one hundred twenty-five feet along the line of travel from the means of egress from any living room. Every such fire-stair shall have a clear width of at least three feet eight inches. Two such fire-stairs shall be deemed adequate for seventy living rooms on any story. For each thirty-five living rooms or fraction thereof in excess of seventy on any story there shall be one additional fire-stair; except that if such fractional excess number of living rooms is not more than twenty per centum of the total number of living rooms provided for by the required two fire-stairs and one additional fire-stair for each thirty-five living rooms, if any, in excess of seventy, in lieu of another fire-stair for such fractional excess number of living rooms, the area of every fire-stair landing at such story may be increased by not less than two square feet for each living room of such fractional excess number of living rooms. In every such dwelling each living room which is occupied by three persons or more shall be counted as one additional room for each four hundred cubic feet or fraction thereof in excess of eight hundred cubic feet in the cubic content of such room.N.Y. Mult. Dwell. Law § 102