What is the minimum clear width of a spiral stairway, at or below the handrail?

The minimum clear width of a spiral stairway, at or below the handrail, is established to ensure safe and accessible passage. According to various building codes and guidelines, the minimum clear width for such a stairway is typically set at 26 inches. This dimension accommodates the safe movement of individuals, including those who may be carrying objects, and provides enough space for comfortable navigation.

When considering the design of spiral stairways, it is crucial to recognize that the tight turning radius and configuration of the stairs can limit effective width. The code aims to prevent narrow, unmanageable pathways that could lead to dangerous situations during regular use or in emergencies. By setting the minimum clear width at 26 inches, building codes strike a balance between functionality and safety, ensuring that the stairway remains usable for a variety of occupants while adhering to essential safety standards.