How is “net area” defined for calculating occupant load?

The definition of "net area" for calculating occupant load is focused on the usable space within a building that can be occupied or utilized by individuals. This includes the floor area that is available for use but excludes spaces that do not contribute directly to the occupants' activities—such as walls, stairs, corridors, and any other non-usable areas.

Using this definition ensures that the calculation for occupant load reflects only those areas where people can safely gather and operate, which is critical for ensuring adequate safety measures, such as egress capacity and emergency planning. By focusing on the usable area, it allows for a more accurate determination of how many people can safely occupy a given space within the building.

Other options include areas that are not relevant for the calculation of occupant load or may introduce components that do not affect how space is actually used. Thus, option B stands out as the correct interpretation of net area.