In model code classifications, which factor is used to separate occupancies into risk categories?

• A. Use of the structure or space
• B. Height of the building
• C. Number of occupants
• D. Proximity to fire stations

Answer: (A)

Risk categories in model codes are driven by what the space is used for and what hazards that use creates. The way the structure or space is used determines the potential fire load, ignition sources, and exposure scenarios, which in turn shape the level of protection and life-safety measures required. That’s why the use of the structure or space is the factor used to separate occupancies into risk categories.

Height, number of occupants, and proximity to fire stations influence other code requirements—like egress capacity, suppression needs, or response considerations—but they do not define the occupancy’s risk category itself. For example, a small shop with hazardous processes may have a higher risk category than a large classroom, precisely because of how the space is used and what it contains.