What type of building construction is known as ordinary construction?

Ordinary construction is primarily characterized by the use of non-combustible materials in its structural framework while incorporating exterior walls made of masonry or other non-combustible materials but with a reliance on wood for its interior framework. This type of construction is notable for its relatively low fire resistance, making it vulnerable to fire spread and collapse under high heat conditions.

Type III construction, or ordinary construction, typically features an interior structure that may be comprised of wood or light-frame materials, providing a significant fire load. The exterior walls, being non-combustible, can slow down fire spread from outside but do not offer the same level of protection as those found in other types of construction, like Type I or Type II, which are engineered for greater fire resistance.

Choosing Type III as the correct answer acknowledges the distinct balance this type of construction represents between economical building techniques and fire safety risks, particularly in urban environments.