Name two construction types that significantly affect collapse risk and why.

• A. Type II (noncombustible) and Type III (ordinary) always safe
• B. Type I (fire-resistive) maintains integrity longer; Type V (wood-frame) tends to fail earlier due to fuel load
• C. Steel and concrete are always safe
• D. Glass steel hybrid always collapses

Answer: (B)

The main factor here is how a building’s construction type influences its ability to withstand heat and maintain structural strength during a fire, which directly affects collapse risk.

Two construction types stand out. Type I fire-resistive structures are designed to resist heat and keep their structural integrity for defined periods. They use materials and protection that slow heat transfer to framing, so beams and columns stay strong longer, delaying collapse and giving occupants more time to escape and firefighters more time to operate.

In contrast, Type V wood-frame buildings rely on combustible framing. The fuel load is high, and as temperatures rise, wood weakens quickly, chars, and can fail, leading to early loss of structural support and a higher chance of collapse.

Other options often miss the point because they imply absolute safety or collapse certainty, or they mix materials in ways that don’t directly explain why collapse risk changes with fire exposure. The contrast between fire-resistive Type I and combustible wood-frame Type V best captures how construction type can dramatically change collapse risk during a fire.