Which construction type has exterior walls, bearing walls, floors, roofs, and supports made completely or partially of wood or smaller dimensions than Type 4?

• A. Type 2
• B. Type 3
• C. Type 4
• D. Type 5

Answer: (D)

Understanding how buildings are classified by construction type helps you anticipate fire behavior and safety risks. The description points to wood-frame construction, where exterior walls, bearing walls, floors, roofs, and all supports are made entirely or largely from wood or from small-dimension wood members. This is Type V construction.

The emphasis on wood throughout the structure, including smaller-than-Type IV members, distinguishes it from other types: Type IV uses heavy timber with larger-dimension members; Type III has noncombustible exterior walls but can have interior wood elements; and Type I or II rely on noncombustible or fire-resistive materials. In short, wood-frame construction is the defining characteristic of this type.