(b) Window openings in exterior walls shall conform with the limitations of table 3-4 chapter twenty-six of the administrative code of the city of New York, unless such windows are fire protected and provided with either a minimum of one sprinkler head per window or window automatic closing devices, acceptable to the department of buildings. 2. The building (a) is of fireproof construction, as provided in section one hundred one of this chapter, or is of class two construction, as provided by the requirements of the building code and regulations of the city of New York in effect prior to December sixth, nineteen hundred sixty-eight; or
(b) if non-fireproof, does not exceed a height of six stories, and eighty-five feet measured to the ceiling of the highest floor in a depth of one hundred feet; or does not exceed a height of seven stories, and eighty-five feet and a depth of one hundred feet and is wet sprinklered throughout; and has a maximum floor area between the two hour rated partitions constructed in accordance with section C26-504.2 of the administrative code of the city of New York of:
(i) three thousand square feet; or
(ii) five thousand square feet if the building is six stories or less in height and is fully wet sprinklered; or
(iii) five thousand square feet if the building is seven stories in height and is fully wet sprinklered and has a stand pipe system; or
(iv) ten thousand square feet if the building is fully wet sprinklered and has one hour rated ceilings.
(c) complies with the requirements of table 3-4 chapter twenty-six of the administrative code of the city of New York for J-2 occupancy. 3. Any part of the building may be occupied for manufacturing and commercial purposes (as permitted by local zoning law or resolution), provided, however, that only the second story and below may be occupied for uses listed as medium fire hazard in rules of the board of standards and appeals implementing the labor law unless the entire building is wet sprinklered; in addition, high fire hazard occupancies shall not be permitted in any portion of the building. 4. All areas occupied for manufacturing or commercial purposes shall be protected by an approved wet-pipe automatic sprinkler system. Such wet-pipe automatic sprinkler system shall extend to and include public hallways and stairways coincidentally serving residential occupancies. 5. All occupancies or tenancies shall be separated by a vertical fire separation, extending to the underside of the floor above and having a minimum fire-resistance rating of at least one hour and conform in all respects with applicable zoning regulations. No separation shall be required between the working and living portions of a joint living-work quarters for artists. 6. The building (a) complies with all requirements imposed on old-law tenements by sections two hundred twelve and two hundred sixteen of this chapter and on converted dwellings by sections one hundred eighty-five, one hundred eighty-six, one hundred eighty-eight, one hundred eighty-nine, one hundred ninety, one hundred ninety-one and one hundred ninety-four of this chapter, in addition to those provided in section two hundred seventy-eight of this article and (b) complies with the standards of lighting, ventilation, size of rooms, alcoves and balconies contained in section C26-1205.0 through and including sections C26-1205.5 and C26-1205.7 of the administrative code of the city of New York, except as otherwise provided in paragraph (d) of subdivision seven of this section. 7. Minimum light and air standards for joint living-work quarters for artists or general residential portions of lofts or manufacturing and commercial buildings altered to residential use shall comply with the following:
(a) Portions of such buildings which are occupied exclusively as joint living-work quarters for artists as permitted by local law shall comply with the following:
(i) The minimum size of a joint living-work quarters for artists shall be twelve hundred square feet of interior space, except as otherwise authorized by the zoning resolution of the city of New York, for units occupied for residential purposes on or before January first, nineteen hundred eighty-five.
(ii) Joint living-work quarters for artists shall conform to the standards for light and ventilation of sections C26-1205.0 through and including section C26-1205.7 of the administrative code of the city of New York.
(b) Portions of such buildings which are occupied exclusively as residential units as permitted by local law shall comply with the following:
(i) Every dwelling unit shall have one or more windows: A. which open onto a street, a court with a dimension of fifteen feet perpendicular to the windows and one hundred square feet minimum area above a setback or a thirty foot rear yard; or B. for corner lots or lots within one hundred feet of a corner, where the minimum horizontal distance between such windows opening onto a rear yard and the rear lot line is at least twenty feet; or C. for interior lots, where the minimum horizontal distance between such windows opening onto a rear yard and any wall opposite such windows on the same or another zoning lot is at least twenty feet and not less than a distance equal to one-third of the total height of such wall above the sill height of such windows; but need not exceed forty feet; or D. for interior lots where the minimum horizontal distance between such windows opening onto a rear yard and any wall opposite such windows on the same or another zoning lot is at least fifteen feet and the minimum size of such dwelling unit is twelve hundred square feet; or E. in no event shall the distance between such windows and the rear lot line be less than five feet; and F. yards and courts may be existing or may be new in buildings seven stories or less in height.
(ii) The minimum required ratio of window area opening onto a street, rear yard, or court to the floor area of every living room shall: A. be ten percent where the floor area of such living room is less than five hundred square feet; or B. decrease, by one percent for every one hundred square feet greater than five hundred square feet of floor area of such living room, to a minimum of five percent; and C. in no event shall the distance between such window area and the rear lot line be less than five feet; and D. at least fifty percent of the required window area shall be openable.
(c) Ventilation of spaces other than living rooms, including enclosed work spaces for joint living-work quarters for artists shall be either in accordance with this section or in accordance with the administrative code of the city of New York.
(d) No building converted pursuant to this article shall be enlarged, except where the underlying zoning district permits residential use. Such an enlargement shall be in conformance with the bulk regulations for conforming residential use for new construction and shall be in conformance with the provisions of section twenty-six of this chapter. No interior floor area enlargement shall be permitted except that a mezzanine with a minimum headroom of seven feet shall be allowed within individual dwelling units, provided that the gross floor area of such mezzanine does not exceed one-third of the floor area contained within such dwelling unit. No mezzanine shall be included as floor area for the purpose of calculating the minimum required size of a living room or a dwelling unit or for calculating floor area devoted to dwellings. For the purpose of this article a mezzanine may be constructed above the level of the roof of a building as long as the aggregate area of roof structures does not exceed one-third of the total roof area and the roof structures conform with applicable building code requirements.
(e) The kitchen located within dwelling units and having a floor area of eighty square feet or more shall have natural ventilation as prescribed in sections 27-749 and 27-750 of chapter twenty-seven of the administrative code of the city of New York. Open kitchens shall be considered as part of the adjacent space where forty percent of the area of the separation between the spaces is open and without doors. If the floor area of the combined space exceeds seven hundred fifty square feet, a separate bedroom shall not be required. When the floor area is less than eighty square feet the kitchenette shall be ventilated by either of the following:
(i) Natural means complying with sections 27-749 and 27-750 of chapter twenty-seven of the administrative code of the city of New York and further that the windows shall have a minimum width of twelve inches, a minimum area of three square feet, or ten percent of the floor area of the space, whichever is greater and be so constructed that at least one-half of their required area may be opened. When the space is located at the top story, the window or windows may be replaced with a skylight whose minimum width shall be twelve inches, whose minimum area shall be four square feet or one-eighth of the floor area of the space, whichever is greater and which shall have ventilation openings of at least one-half of the required area of the skylight.
(ii) Mechanical means exhausting at least two cubic feet per minute of air per square foot of floor area. Where doors are to be used to separate the space, the lower portion of each door shall have a metal grill containing at least forty-eight square inches of clean openings or in lieu of such grill, two clear opening spaces may be provided, each of at least twenty-four square inches, one between the bottom of each door and the floor and the other between the top of each door and the head jamb.
(f) When bathrooms and toilet rooms are ventilated by natural means, the natural ventilation sources shall comply with sub-article 1205.0 of chapter twenty-six of the administrative code of the city of New York and shall have an unobstructed free area of at least five percent of the floor area. In no case shall the net free area of the ventilation sources be less than one and one-half square feet. When bathrooms and toilet rooms are vented by mechanical means, individual vent shafts or ducts constructed of non-combustible materials with a minimum cross section area of one square foot shall be utilized, the exhaust system shall be capable of exhausting at least fifty cubic feet per minute of air. Means shall be provided for egress of air by louvers in doors, by undercutting the door, or by transfer ducts, grills or other openings. Toilet exhaust systems shall be arranged to expel air directly to the outdoors.
(g) A single station smoke detector shall be installed immediately outside each sleeping or bedroom area of each dwelling unit. Such device shall be designed and installed so as to detect smoke and activate an alarm, be reasonably free from false alarms and provide visible indication that the alarm is energized. Such device shall be directly connected to the lighting circuit of the dwelling or rooming unit with no intervening wall switch and shall provide a warning signal clearly audible in all sleeping quarters with intervening doors closed. Cord connected installations or smoke detectors which rely exclusively on batteries are not permissible. Such devices shall either be approved or listed by an acceptable testing service or laboratory. 8. All openings from apartments leading into a public hall or corridor shall be provided with fireproof doors and assemblies with the doors self-closing. Partitions between apartments on each floor shall be one hour fire rated partitions. All windows opening on fire escapes shall be provided with wire glass, unless such windows are protected by a wet pipe sprinkler head with a minimum of one head per window. 9. Such buildings, in regard to egress, shall comply with the following:
(a) In a non-fireproof building there shall be:
(i) one independently enclosed stairway and a fire escape from each dwelling unit; or
(ii) where the building is fully wet sprinklered and not in excess of seventy-five feet in height and not exceeding five thousand square feet in building area one independently enclosed stairway from each dwelling, and an independently enclosed hallway, of one hour fire rating where there are two or more tenants on a floor; or
(iii) a sprinklered enclosed hallway with access to two independently enclosed stairs.
(b) In a fireproof building, there shall be:
(i) an enclosed hallway and two independently enclosed stairs; or
(ii) an enclosed hallway and one independently enclosed stair and a screened exterior stair in conformance with section two hundred sixty-eight of the labor law with all glazed openings thereon equipped with wire glass; or
(iii) for buildings not exceeding seven stories or seventy-five feet in height, egress conforming with the provisions of paragraph (a) of this subdivision; or
(iv) egress conforming with the provisions of section one hundred two of this chapter.
(c) No more than two dwelling units shall open directly to a stair without an intervening enclosed hallway.
(d) Enclosed hallways shall have a one hour fire rating.
(e) Enclosed stairways shall be:
(i) one hour fire rated in non-fireproof buildings four stories or less in height; or
(ii) one hour fire rated and sprinklered in non-fireproof buildings six stories or less in height; or
(iii) one hour fire rated in non-fireproof, fully sprinklered buildings seven stories in height; or
(iv) two hour fire rated in all other cases.
(f) The travel distance to the means of egress shall comply with the administrative code of the city of New York.
(g) Wooden stairs permitted by section one hundred eighty-nine of this chapter may be retained only if, in addition to meeting all of the requirements set forth therein, they are within a fully wet-sprinklered enclosure, and the stair and landing soffit are fire retarded, notwithstanding any other provisions.
(h) Every required stair shall extend through the roof by a bulkhead, except that a scuttle may be used if the dwelling does not exceed four stories and except that no bulkhead or scuttle is required where the roof is a peak roof with a pitch of more than fifteen degrees.
(i) Mezzanines shall be provided with a stair at least two feet six inches wide terminating not more than twenty feet from an exit door or fire escape, and all portions of such mezzanines shall be not more than fifty feet from such exit door or fire escape. 10. In buildings in excess of two stories in height, stairways shall be provided with skylights at least twenty square feet in area, glazed with plain glass with a wire screen over and under and provided with fixed or movable ventilators having a minimum open area of one hundred forty-four square inches. In lieu of the skylight and ventilators, a window of equal area may be provided with fixed louvers having a minimum open area of one hundred forty-four square inches installed in or immediately adjacent to the window. 11. Except as otherwise provided in this article, all shafts shall be enclosed with incombustible material of two hour fire rating and comply with the administrative code of the city of New York, provided, however, existing shaft enclosures constructed in part of combustible material may be retained if upgraded to obtain a two hour fire rating. 12. Every kitchen or kitchenette or cooking space in such building shall comply with the requirements imposed on multiple dwellings erected after April eighteenth, nineteen hundred twenty-nine by section thirty-three of this chapter. 13. Such building shall comply with all requirements imposed on multiple dwellings erected after April eighteenth, nineteen hundred twenty-nine by title three of article three of this chapter. 14. All interior iron columns in unsprinklered buildings shall be protected by materials or assemblies having a fire-resistive rating of at least three hours. Where sprinklers are provided for an exterior wall as provided in subdivision one of this section or in a fully wet sprinklered building such columns shall be protected by two sprinkler heads located eighteen inches or more away and each on opposite sides of such column but no further than four feet. Such sprinklers shall be provided at any interior column where fire protection is omitted in non-fireproof buildings. 15. The elevator shafts in such buildings shall be enclosed with incombustible material of two hour fire rating, except that existing elevator shaft enclosures constructed in part of combustible material may be retained if upgraded to obtain a two hour fire rating; and have fireproof doors and assemblies with (a) the doors self-closing; or (b) a vestibule the walls of which shall be of non-combustible material and have a minimum two hour fire resistive rating, with self-closing fireproof doors and be fire-stopped; or (c) where the elevator is manually operated in fully sprinklered buildings have fireproof doors, with approved interlock devices. 16. The requirements and standards prescribed in this section shall be subject to variation in specific cases by the commissioner of buildings, or the board of standards and appeals, of such city under and pursuant to the provisions of paragraph two of subdivision b of section six hundred forty-five and section six hundred sixty-six of the New York city charter.