How are occupant load factors used in egress design?

• A. They determine the number of occupants for spaces, which informs required exit capacities, number and size of exits, and aisle widths.
• B. They determine HVAC sizing only.
• C. They determine lighting levels.
• D. They determine restroom locations.

Answer: (A)

Occupant loads are used to translate the area of a space into a likely number of people, and that number drives egress provisions. Codes provide occupant load factors for different uses, so you multiply a space’s floor area by the factor for that use to estimate how many people could be there. That count then sets the required egress capacities: how many exits are needed, the size (and arrangement) of those exits, and the minimum widths of exits, aisles, and stairs to safely move people out of the building in a prompt and orderly way. If more people could be present, the design must accommodate larger or more exits and wider paths to maintain safe travel times and comply with maximum travel distances. The other options—HVAC sizing, lighting levels, or restroom locations—aren’t the primary drivers of egress design from occupant load factors.