N.Y. Multiple Residence Law § 28

§ 28. Stairs and entrance halls. In every such dwelling three stories\nor more in height the wood wainscoting and other combustible materials\non the wall and ceiling surfaces in all halls shall be removed and\nreplaced with incombustible or other fire-resistive materials. In lieu\nof such removal, a sprinkler system may be installed in such halls or\nsuch wainscoting and the combustible surfaces may be treated or covered\nin a manner satisfactory to the department with a surface fire-retardant\napproved by the department. In such a dwelling, however, any entrance\ndoor and every door opening into any entrance hall, stair hall, or other\npublic hall connected therewith, shall be self-closing. Every interior\nsash, or opening other than a door, in the walls or partitions of such\nhalls and every window therein not opening to the outer air shall be\nsealed with fire-resistive materials.\n