The IBC classifies buildings in one of five different construction types, I, II, III, IV, or V, based on the materials used to build the structure and fire-resistance rating required. Each type of construction, except IV, has an additional A and B designation based on the required fire-resistance rating for different building elements. This report will focus on Type III-A building construction, which requires the exterior walls to be of noncombustible materials and have a fire-resistance rating of 2 hours or less, but the interior building elements consist of any material allowed by the code.

This Code Summary Report will discuss the different materials permitted to be used in Type III-A construction, with an emphasis on the use of fire-retardant-treated wood (FRTW).