If a Type V building is not balloon-frame, which framing system is it?

A Type V building, commonly referred to as a wood-frame structure, has specific definitions related to its construction and framing systems. If a Type V building is not balloon-frame, the alternative framing system utilized is platform-frame.

Platform-frame construction is characterized by the use of horizontal framing members that are laid out one floor at a time. Each floor is constructed independently on top of the ground floor, forming a "platform." This method contrasts with balloon framing, where the wall studs run continuously from the foundation to the roof, allowing for a different distribution of weight and fire behavior.

Platform framing is widely used in residential structures due to its simplicity and efficiency, making it easier to install insulation and utilities compared to balloon framing. This type of construction enhances fire safety because the vertical spaces through which fire could spread are minimized for each floor. Hence, if a Type V building cannot be classified as balloon-frame, platform-frame is the structure that fits this description effectively, making it the correct answer in this context.