Model code organizations have developed classifications that separate each occupancy into risk categories based upon the:

The classification of occupancy into risk categories by model code organizations is primarily based on the use of the structure or space. This approach allows for a systematic evaluation of the potential hazards and risks associated with different types of occupancy. Each type of use—such as residential, commercial, industrial, and assembly—presents unique fire safety challenges and risks that need to be addressed in building codes and safety regulations.

By categorizing occupancy based on use, code organizations can ensure that specific fire protection measures, evacuation strategies, and construction standards are applied appropriately. Different uses may result in varying occupancy densities, hazards, and firefighting requirements, thus necessitating tailored safety provisions.

In contrast, aspects like the type of truss system present, the structure’s location, or the height and width of the building, while relevant in their own contexts, do not directly determine the risk associated with the occupancy type. These factors may influence structural integrity and response strategies but are not foundational to the occupancy classification in the way that the intended use of the structure is.