Which type of construction is referred to as ordinary construction?

Ordinary construction is specifically characterized by buildings that have exterior walls constructed from non-combustible materials, typically masonry, but may utilize wooden frame interiors. This type allows for greater fire resistance compared to buildings made entirely from wood, while still having vulnerable interior components that can ignite and contribute to fire spread. Type III construction encompasses this definition, making it the correct choice.

In contrast, Type I construction is known for its fire-resistive materials and is often used for high-rise buildings, while Type II construction is notable for non-combustible materials but doesn’t encompass the same combustible interior characteristics. Type IV construction, also known as heavy timber construction, uses large wooden elements that can resist fire for a longer duration but is still primarily defined by a predominance of heavier wood materials throughout. Understanding these distinctions helps clarify why ordinary construction aligns with the characteristics of Type III.