International Building Code

SUBJECT: Incidental Use Areas
CHANGE TYPE: Clarification

302.1.1 508.2 Incidental Uses Areas. Incidental use areas shall comply with the provisions of this section.

Exception: Incidental use areas within and serving a dwelling unit are not required to comply with this section.

508.2.1 Occupancy Classification. Spaces which are incidental to the main occupancy shall be separated or protected, or both, in accordance with Table 302.1.1 or the building shall be classified as a mixed occupancy and comply with Section 302.3. Areas that are incidental to the main occupancy An incidental use area shall be classified in accordance with the main occupancy of the that portion of the building in which the incidental use area it is located or the building shall be classified as a mixed occupancy and shall comply with Section 508.3.

Exception: Incidental use areas within and serving a dwelling unit are not required to comply with this section.

508.2.2 Separation. Incidental use areas shall be separated or protected, or both, in accordance with Table 508.2.

302.1.1.1 508.2.2.1 Separation Construction. Where Table 302.1.1 508.2 requires a fire-resistance-rated separation, the incidental use area shall be separated from the remainder of the building with by a fire barrier in accordance with Section 706 or a horizontal assembly constructed in accordance with Section 711, or both. Where Table 302.1.1 508.2 permits an automatic fire-extinguishing system without a fire barrier, the incidental use area shall be separated from the remainder of the building by construction capable of resisting the passage of smoke. The partitions shall extend from the floor to the underside of the fire-resistance-rated floor/ceiling assembly or fire-resistance-rated roof/ceiling assembly or to the underside of the floor or roof deck above. Doors shall be self-closing or automatic-closing upon detection of smoke. Doors shall not have air transfer openings and shall not be undercut in excess of the clearance permitted in accordance with NFPA 80.

508.2.3 Protection. Where an automatic fire-extinguishing system or an automatic sprinkler system is provided in accordance with Table 508.2, only the incidental use areas need be equipped with such a system.

CHANGE SIGNIFICANCE: Incidental uses are generally considered ancillary functions that are associated with a given occupancy and generally pose a greater level of risk to that occupancy. However, such uses regulated as incidental use areas are limited only to those specifically listed in Table 508.2. Except in those few circumstances where consideration as a mixed-occupancy condition is appropriate, the occupancy classification of an incidental use area is consistent with that of the occupancy group it serves.

The relocation and reorganization of the incidental use area provisions allow for a clearer understanding of the requirements. In addition, the revised format is consistent with the approach utilized for accessory occupancies, nonseparated occupancies and separated occupancies.