Restaurant Conversion in an Existing Sprinklered Office Building
A developer applies to convert part of the first floor of an existing two-story, Type III-B office building into a restaurant. The building is fully sprinklered under NFPA 13 and has two interior stairs, each 44 inches clear, serving both floors. The proposed first-floor program is: 2,000 sf dining with tables and chairs, 600 sf bar area with standing room, 1,200 sf kitchen, 700 sf walk-in storage, and 1,500 sf of remaining office. The 8,000 sf second floor is open office and is unchanged.
The applicant's egress analysis lists 210 occupants on the first floor and concludes the two existing stairs are adequate. Reviewing the plan set, you find no information about the bar area's seating, and the storage room is labeled "unoccupied, not counted."
1. Recalculate the occupant load for each floor and for the building. Where does the applicant's number go wrong, and why does the correction matter to the rest of the review?
Read the worked answer
Apply the factors in Table 1004.1.2, round each value up, and never let an applicant delete a space from the count:
| Space | Factor | Load |
|---|---|---|
| 2,000 sf dining (tables and chairs) | 15 net | 134 |
| 600 sf bar (standing) | 5 net | 120 |
| 1,200 sf kitchen | 200 gross | 6 |
| 700 sf storage | 300 gross | 3 |
| 1,500 sf office | 150 gross | 10 |
| First floor | 273 | |
| 8,000 sf office, 2nd floor | 150 gross | 54 |
| Building | 327 |
The error is the bar area. Applying the 15 net assembly factor to 600 sf yields 40 occupants; standing space is 5 net, yielding 120. That single line explains most of the gap between 210 and 273. Storage is not "unoccupied" - it is a 300 gross space and must be counted.
The correction matters because occupant load is the input to exit count, egress width, door leaf size and swing, panic hardware, corridor width, plumbing fixture counts under Chapter 29, and the required separation of exits. An understated load quietly undercuts all of those checks.
2. Using your total, evaluate whether the two existing 44-inch stairs are adequate for exit count and egress width. Show the arithmetic and state what else you must verify about those stairs before approving.
Read the worked answer
Exit count. 327 occupants is below 500, so two exits from the story are permitted, and two exist. Exit count passes - but only because the story is sprinklered and the two exits are genuinely separate.
Capacity. In a sprinklered building, stairs are sized at 0.2 inch per occupant and other egress components at 0.15 inch per occupant. The stairs carry the accumulated load of both floors: 327 x 0.2 = 65.4 inches required, 88 inches provided - adequate. Doors and corridors: 327 x 0.15 = 49.1 inches total, so the individual door leaves, the corridor serving the dining and bar, and the exit access doorways must each be checked against that number and against minimum widths.
What still has to be verified. That 44 inches is clear width between handrails, not frame-to-frame; the minimum stair width where the occupant load exceeds 50; confirmed remoteness of the two exits; that both stairs discharge directly to the exterior without passing through the restaurant; and that no exit serves only the second floor while the first floor relies on it.
3. The applicant argues the 600 sf bar is not standing space because 12 stools will be installed, and asks you to drop the bar from the calculation entirely. How do you rule?
Read the worked answer
Deny the request to delete the area. Occupant load is based on the actual intended use, and the code's table values are minimums - an applicant may not go below them without the building official's approval based on demonstrated, enforceable facts.
The applicant's own proposal establishes the problem: 12 stools occupy a fraction of 600 sf. The remaining floor area is where patrons stand to order, wait, and socialize, and it functions as standing space. Two defensible outcomes:
- Accept a documented mixed calculation - 12 fixed seats counted by seat, plus the residual floor area at 5 net standing space, provided the plan clearly shows the fixed-seat footprint and the residual area.
- Keep the full 120-occupant figure if the plan does not clearly commit to the layout.
What is not acceptable is a narrative assertion that a bar with 600 sf of floor and 12 stools will never hold more than 12 people. If the applicant wants the lower number, the burden is on them to show a design that physically supports it, and the approved plans must show it, because the inspector will build to the plans.