What type of construction allows for more combustible materials to be used?

Type III construction is characterized by its use of combustible materials for its internal structures while maintaining non-combustible exterior walls. This type of construction allows for a significant amount of wood or other combustible materials to be used within the frame, making it a common choice for residential buildings, small commercial properties, and places where aesthetic considerations might include exposed wood elements.

The primary design advantage of Type III construction is its balance of vulnerability to fire and structural integrity, which can be useful for certain applications where cost and aesthetics matter. However, the presence of combustible materials can also lead to increased fire risk if not appropriately managed through code compliance and fire prevention measures.

In contrast, the other construction types, such as Type I and Type II, are designed with fire-resistant materials throughout the structure, significantly limiting the number of combustible components. Type IV construction, while allowing for heavier timber, still enforces restrictions that do not apply as flexibly as in Type III. This makes Type III unique in its allowance for more combustible materials compared to the other construction types.