“ (2) The maximum vertical rise of a single flight of
stairs between floors, between landings or platforms, or
between a floor and a landing or platform, shall not
exceed eight feet in buildings classified in occupancy
groups F and H, and twelve feet in all other occupancy
groups. No flight of stairs shall have less than two risers. “
http://www.nyc.gov/html/dob/downloads/bldgs_code/bc27s6.pdf
