Coffee Bar Inside an Existing Mercantile Building
An existing 10,000 sq ft, fully sprinklered, Type IIB mercantile building has two exits. The owner proposes a 900 sq ft coffee bar with 28 seats and a counter inside the store, open to the sales floor with no separation. The coffee bar will have a 30 in. high counter, a small kitchen with a Type I hood, and seating along the front window. The building has a 60 ft common path from the coffee bar to the nearest exit and 110 ft to the second exit. The store occupant load is 150; the coffee bar is calculated at 60 occupants by area. The owner wants to know whether the coffee bar can be an accessory use without a fire separation, whether the exits are adequate, and what code documentation is needed.
1. Classify the coffee bar occupancy and determine whether it may be treated as an accessory occupancy without separation. Show the area calculation and state the conditions.
Read the worked answer
A coffee bar where food and drink are consumed is Group A-2, not Group M. The key question is whether it qualifies as an accessory occupancy under IBC 508.2.
Area check: 900 ÷ 10,000 = 9.0%, which is below the 10% accessory-occupancy limit. If the use is ancillary to the mercantile occupancy and does not introduce a higher-hazard use, it can be treated as accessory, and no separation is required between it and the sales floor. The 28 seats and 60 calculated occupants must still be counted for egress.
The conclusion changes if the coffee bar is expanded, becomes a standalone destination, or introduces a use that is not ancillary. A Type I hood and commercial cooking also trigger kitchen suppression and exhaust requirements independent of the occupancy separation. The designer should document the accessory-occupancy analysis and confirm that the A-2 use does not exceed 10% of the floor area.
2. Evaluate the exit and common-path arrangement for the combined store and coffee bar. Use the stated occupant loads and dimensions.
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Total occupant load = 150 + 60 = 210. Two exits are required because the occupant load exceeds the one-exit limits for both M and A-2. Two exits exist, so the number is adequate in principle.
Egress capacity: at 0.2 in. per occupant for sprinklered egress components, 210 × 0.2 = 42 in. total. The two exits must be sized so the loss of one does not reduce capacity below the required amount, and each exit must be at least the minimum width. The stated dimensions do not give door widths, so capacity cannot be closed out without them.
Common path: 60 ft. For sprinklered A-2 and M occupancies, the common-path limit is typically 75 ft; 60 ft is within that limit. Travel distance to the second exit is 110 ft, well below the 250 ft sprinklered limit. The exits must also be remote from each other; the plan must show that the 110 ft route does not pass through the same fire area in a way that makes both exits unavailable in one event. Seating along the front window must not obstruct the required exit access or the accessible route.
3. The owner later expands the coffee bar to 1,200 sq ft. What changes in the code analysis, and what documentation should be submitted?
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At 1,200 sq ft, the coffee bar is 1,200 ÷ 10,000 = 12% of the floor area, exceeding the 10% accessory-occupancy limit. It can no longer be treated as an accessory occupancy on area alone.
The designer must either:
- separate the A-2 occupancy from the M occupancy with a fire-resistance rating determined from IBC Table 508.4, or
- use the nonseparated-occupancy provisions of IBC 508.3, where the most restrictive requirements apply and the building is protected accordingly.
The occupant load also increases to 1,200 ÷ 15 = 80 for the coffee bar, so the total becomes 230. Exit capacity, common path, and travel distance must be recalculated. The Type I hood, grease duct, and kitchen suppression require separate submittals.
Documentation should include a code-analysis narrative with the area calculation, occupancy classification, separation table reference, occupant-load calculations, exit-capacity calculations, and a plan showing the common path and exit remoteness. If the owner wants to avoid a rated separation, the nonseparated analysis must be signed and incorporated into the permit drawings.