Group ratings are typically expressed as a number of minutes, which indicates the length of time that the material can withstand the effects of fire. The higher the group rating, the more fire- resistant the material is considered to be. In addition to group ratings, the Australian Building Code also specifies other requirements for construction materials, such as their structural strength and durability.

In summary, group ratings of construction materials are an important aspect of the Australian Building Code because they help to ensure the safety and integrity of buildings in the event of a fire. They are used to determine the minimum fire resistance levels that must be met by different building elements and help to protect the lives and property of building occupants.