external fire escape
A fixed external stairway, ladder, or slide providing an escape route from each occupiable floor to ground level.
A fire escape is an external structure accessible from each occupiable level of a structure which provides access to the ground as a potential emergency escape. It can be a stairway, ladder, slide, pole, or other similar means of egress.
Mobile escape hatches or platforms, rope ladders, and hoists do not count as fire escapes. However a fire escape may have movable parts, such as hinges which extend a stairway when stepped upon.
The external route must reach the ground and be accessible from each occupiable level. Movable components of the fixed installation are permitted, while mobile escape equipment, rope ladders, and hoists remain excluded.