Final answer:
In a multi-story building, the egress stairway width is calculated based on the number of occupants expected to use the stairway. Building codes, such as the International Building Code (IBC), provide guidelines for minimum egress stairway width based on the total occupant load served by the stairway. The minimum width increases proportionally with a larger occupant load.
Step-by-step explanation:
In a multi-story building, the egress stairway width is calculated based on the number of occupants expected to use the stairway. The calculation takes into account the required egress capacity, which is typically based on building codes and standards. It is usually determined by the occupancy type, number of floors, and floor area of the building.
For example, the International Building Code (IBC) provides guidelines for minimum egress stairway width. According to the IBC, the minimum clear width of an egress stairway should be based on the total occupant load served by the stairway. For a building with an occupant load of up to 50 people, the minimum width should be 44 inches (or 3 feet 8 inches). For buildings with a larger occupant load, the width increases proportionally to ensure adequate egress capacity.
It's important to note that these are general guidelines, and building codes may vary depending on the specific jurisdiction.