Which factor is commonly used to determine a protected stairwell's fire rating?

Which factor is commonly used to determine a protected stairwell's fire rating?

• A. Building age
• B. Occupancy
• C. Stair height
• D. Exterior color

Answer: (B)

Occupancy type drives the required fire resistance of protected stairwells. The reason is that different uses create different fire hazards and occupant risks, so codes set minimum fire-resistance ratings for exit enclosures to ensure people can evacuate safely and the stairs stay intact long enough for emergency actions. A high-risk, high-occupancy space (with more people and higher fire loads) typically requires a more substantial rating than a simpler occupancy. Building age can influence retrofit considerations but doesn’t determine the rating itself; stair height affects design details, not the fire-resistance requirement; exterior color has no bearing on fire protection.

Occupancy type drives the required fire resistance of protected stairwells. The reason is that different uses create different fire hazards and occupant risks, so codes set minimum fire-resistance ratings for exit enclosures to ensure people can evacuate safely and the stairs stay intact long enough for emergency actions. A high-risk, high-occupancy space (with more people and higher fire loads) typically requires a more substantial rating than a simpler occupancy. Building age can influence retrofit considerations but doesn’t determine the rating itself; stair height affects design details, not the fire-resistance requirement; exterior color has no bearing on fire protection.