Building Official Determination 19-05: Small Assembly Occupancies

OSSC 303.1.2, Table 1004.1.2, and 903.2.1.2

QUESTION: What occupancy classification should be assigned to a dining/drinking establishment that contains more than one room with seating and gathering? Are there any restrictions on how large the openings between rooms can be? 

RESPONSE: An assembly space, such as a dining establishment or bar, that contains more than one room shall be classified as a "B" Occupancy under the following conditions:

1. Each room that is part of the dining/drinking establishment use shall have a calculated occupant load of 49 persons or less including service personnel.
2. Each room shall have a minimum of one code compliant exit that is independent of the egress system of any of the other rooms and that does not combine with the egress systems from other rooms or other areas of the building in which the use is located until the point of exit discharge to a public way is achieved.
3. Each assembly room shall be separated from other assembly rooms by full height walls and must meet both of the following conditions:
   1. Aggregate openings in the common wall separating two "B" assembly rooms shall be less than 50% of the common wall area, AND
   2. At least 50% of the linear length of the common wall must extend to the floor.
4. Wall area and length calculations:
   1. Only those portions of the common separation wall between assembly spaces shall be included in the wall calculations.  Adjoining accessory support rooms and spaces such as kitchens, storage rooms, service counter areas and restrooms are excluded from the calculations.
   2. The total wall area used to calculate the allowable openings is based on the length of the common wall between "B" assembly rooms times the height of the separation wall. The separation wall height is measured from the finish floor to the lowest ceiling of either room.
5. A draft curtain shall be provided at each opening between rooms extending a minimum of 24" below the ceiling.
6. The total occupant load for the dining/drinking establishment, including service personnel, shall not exceed 99 persons.
7. Each room that is part of the dining/drinking establishment use shall have the occupant load posted near the exit.

HISTORY: Implemented August 7, 2019. Updated May 4. 2026.

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