N.Y. Multiple Residence Law § 138

§ 138. Parapets and guard railings. Except as hereinafter provided\nevery open area of a roof, terrace, areaway, outside stair, retaining\nwall or porch shall be protected by a parapet wall, a guard railing, or\nboth, extending three feet six inches or more in height above the level\nof such area or, in the case of a stair landing, stair window or window\nin a public hall, above the level of the floor adjacent thereto. In\ndwellings two stories in height, it shall be sufficient if the guard\nrailing is erected at least five feet distant from and encloses any\nrequired bulkhead or scuttle opening to the roof. This section shall not\napply to dwellings one story in height.\n