In NFPA 13, hazard classification (e.g., light, ordinary, extra) primarily influences which design aspect?

• A. The color of sprinkler heads
• B. Sprinkler head spacing and density
• C. The number of alarms
• D. The building height

Answer: (B)

In NFPA 13, how much water per area and how closely sprinklers must be placed is set by how severe the fire hazard is in that space. Hazard classification (light, ordinary, extra) tells you the required discharge density and, from there, the design area and spacing for sprinklers. So, the key design outcome that changes with hazard is sprinkler head spacing and the overall density of sprinklers to meet the needed water supply for that hazard level.

The color of sprinkler heads is generally about temperature rating or head type, not the fire hazard. Building height is determined by structural and occupancy factors rather than hazard classification, and the number of alarms relates to the fire alarm system design, not the water-based sprinkler layout.