Occupancy Class Descriptions

AIR provides the following categories of occupancy class codes:

Code Range



Unknown occupancy

301-307, 382

Residential occupancies

311-319, 383

Commercial occupancies

321-330, 384

Industrial occupancies


Restaurant occupancy


Mercantile occupancies


Public occupancies


Education occupancies


Transportation occupancies


Utility occupancies


Miscellaneous occupancies


Industrial facility occupancies


Offshore asset occupancies

Usage notes

       When choosing between a 300-series code and a 400-series code, you need to be aware of some key differences that require knowledge of the facility and what the policy terms cover (the entire facility or the main buildings at a site). The 300-series codes are tuned to account for losses stemming from primary industrial structures—the actual buildings or major structures at an industrial site; they are not tuned for secondary structures such as tanks, manufacturing equipment, etc. The 400-series codes account for the secondary structures using a component-based approach to evaluate damage to an entire industrial facility, including the elements listed above. From a coding perspective, there is no distinct construction code associated with a 400-series occupancy; they are modeled with unknown construction. Click here for AIR's "Providing a Reliable Solution for Modeling Large Industrial Facilities" document.

       Industrial buildings have features that make them generally more vulnerable to damage than other type of buildings, given the same construction types. These features include larger windows or doors, longer roof spans, and roof cover types that are more vulnerable to winds. Within the class of industrial buildings there is also variation in wind vulnerability. Light-metal buildings have been observed to be significantly vulnerable to damage by moderate to high level of winds as compared to concrete and steel-frame buildings. Similarly, wood and masonry constructions are generally more vulnerable to winds than the concrete and steel framed buildings. The new US Hurricane model captures those variations explicitly.

       Compared to the previous version of the US Hurricane model, the wind vulnerability of an industrial building with an "unknown" construction type has not changed significantly; that is, AIR's understanding of vulnerability for a generic industrial building remains the same. However, since the previous version of the model does not distinguish between different construction types while the new model does, you will observe increases in losses for wood, masonry, and light-frame constructions, and decreases in losses for concrete and steel-frame buildings. Accordingly, depending on the mix of construction types for the industrial buildings within the portfolio, you may observe increases or decrease.



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Touchstone 5.0 Updated January 17, 2019