Egress and Occupant Load in a Warehouse Restaurant Conversion

Using a typical restaurant occupant-load factor of 15 net square feet per person, 6,000 square feet divided by 15 equals 400 occupants on the main floor, and 1,200 square feet divided by 15 equals 80 on the mezzanine, for a calculated load of 480. The proposed 420 is lower, but the design team must show how the seating, bar standing area, and stage are counted; a concentrated bar or standing area can produce a higher load than the area factor suggests. The AHJ will use the greater of the calculated or proposed load where fixed seating and standing areas are involved.

For egress capacity, using typical sprinklered values of 0.15 inch per occupant at doors and corridors, 420 occupants require about 63 inches of clear width. Two 36-inch doors, with roughly 34 inches clear each, provide about 68 inches, so door capacity is marginal but not automatically deficient. The more serious issues are the number of exits and the mezzanine. A 420-occupant assembly space needs at least two remote exits, and the two doors must be separated so a single fire cannot block both. The mezzanine with 80 occupants and one stair is a likely violation; a single stair is generally limited to a much smaller occupant load, and the stair must be enclosed or separated as required. The rear door step and sloped alley create an exit-discharge hazard, and the stage may create a concentrated load or obstruct an exit. These are the issues to bring to the AHJ.

The cleanest solution is to add a second independent means of egress from the mezzanine, either a compliant stair to the main floor at the opposite end from the existing stair or an exterior stair if the facade and landlord allow it. If a second stair is impossible, the mezzanine occupant load must be reduced to the single-exit threshold accepted by the AHJ, which may mean limiting it to about 49 occupants or fewer and using it for small groups rather than 80 diners. That is a business decision as much as a code decision, and the owner should see the trade-off.

At the main floor, I would keep the front and rear exits but remove or ramp the rear step and provide a level landing at the door. I would also verify that the path from the mezzanine stair discharges without passing through the kitchen or a locked vestibule. The stage should be located away from the exits and reviewed as a concentrated load and as a possible obstruction to egress. If the calculated load is 480, the design team should either reduce fixed seating and bar standing capacity or add egress width and a third exit. I would not approve the 420-person plan until the exit remoteness, mezzanine stair, and exit discharge are resolved in a code review with the AHJ.

The project should verify a complete automatic sprinkler system, not just a partial system, and confirm that the sprinkler design accounts for the mezzanine and any stage curtains or set pieces. The stage may trigger a proscenium or fire-curtain requirement depending on its size and construction; even a small stage can introduce combustible scenery and lighting loads. The building should have an approved fire-alarm system with notification appliances audible and visible throughout the dining, bar, and mezzanine areas, and exit signs at the front, rear, and mezzanine stair.

Emergency lighting is critical because the dining and bar areas may be dimly lit. I would verify that the path from the mezzanine to the exterior is illuminated and that the rear alley exit has a maintained illuminated exit sign. The owner should also provide a written occupancy plan because the proposed 420 load, the bar standing area, and the stage may change with events. If the AHJ permits alcohol service, crowd-management and exit-access provisions may be reviewed separately. The architect should document the maximum approved occupant load and ensure that furniture layouts and event setups do not exceed it.