Structures classified for incidental use must conform their fire protection systems to the:

• A. code specifics for residential occupancies.
• B. code specifics for institutional occupancies.
• C. requirements for the primary use of the structure.
• D. requirements for the secondary use of the structure.

Answer: (C)

The important idea is that fire protection design for a structure is driven by the building’s main purpose. Incidental or accessory uses don’t change the overall risk profile enough to require a separate, occupancy-specific design; instead, the fire protection system is aligned with the requirements for the primary use of the structure.

In practice, this means the building’s primary occupancy dictates the level of protection, including detection, alarm, suppression, and egress design. Incidental areas are included within that overall system and must be protected accordingly, but they don’t override the primary occupancy classification. If the incidental use were substantial enough to alter the risk, then a reevaluation would be necessary, but under normal circumstances the protection conforms to the primary use.