Restaurant Conversion: Occupant Load, Egress, and Exit Path
A 3,500 sq ft tenant space in an existing unsprinklered masonry building is being converted from retail to a restaurant. The dining room measures 1,850 sq ft net, the bar area 350 sq ft, the kitchen 800 sq ft, and restrooms and storage 500 sq ft. The architect calculates the dining room at 15 sq ft per person and the bar at 15 sq ft per person, with staff counted in the total. Egress is a 36 in. front door that swings inward, and a 32 in. rear service door reached only by walking through the kitchen. The farthest point in the dining room is 165 ft from the front door. Doors are fitted with lever hardware and a deadbolt. Emergency lighting exists only in the corridor outside the tenant space. The owner wants to open in six weeks and asks whether a fire alarm system is even required, since the space has never had one.
1. Calculate the occupant load and the required egress width, and determine whether the exits are adequate.
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Occupant load. Dining 1,850 ÷ 15 = 123.3 → 124. Bar 350 ÷ 15 = 23.3 → 24. Total = 148 persons.
Required width (level components, unsprinklered). 148 × 0.2 in. = 29.6 in. of clear width. Because there are two exits, each must provide at least half the required capacity, but the minimum clear width of a door serving this load still controls at 32 in. - so a 36 in. door and a 32 in. door are each individually adequate for width. (Had the building been sprinklered, 0.15 in. per person would apply.)
Number of exits. At 148 occupants this is an assembly occupancy well above the threshold for a single exit, so two means of egress are required and they must be remote from each other. The count is satisfied on paper - but only if both exits are actually usable.
The width arithmetic is fine. The failure is in the arrangement: one exit is reached only through the kitchen, which is not an acceptable exit access path, so in practice the space has one usable exit for 148 people.
2. Explain why the rear door through the kitchen does not count, and address door swing, hardware, and emergency lighting.
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Kitchen path. Exit access may not pass through a kitchen or similar space. The kitchen is a cooking/hazard area with heat, grease, and equipment that can block the path, and it is not arranged or protected as a corridor. A 32 in. door at the end of it cannot be counted as a required exit for the dining and bar occupants.
Door swing. The front door swings inward against the direction of egress. Doors serving an assembly space for a large occupant load must swing in the direction of exit travel, so the front door needs to be reversed or replaced.
Hardware. Lever hardware with a deadbolt is not acceptable. Doors serving an assembly occupancy must have panic hardware, and the deadbolt, which requires two operations to release, must be removed.
Emergency lighting. Required means of egress must have emergency illumination and exit signs. Corridor-only coverage leaves the dining room, bar, and exit discharge dark on power failure; add battery-backed units and exit signage at both discharge points.
Net result: the plan needs a real second remote exit, a rehung front door, panic hardware, and egress lighting before occupancy.
3. Is 165 ft acceptable, and what is the regulatory path in Maine before the owner opens?
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Travel distance. For an unsprinklered assembly space, the exit access travel distance limit is 200 ft; 165 ft is within that limit - but distance is measured to the nearest acceptable exit. With the kitchen route disallowed, the measurement is to the front door only, and the value still has to be verified along the actual path of travel, not a straight line on the plan. Also check common path and the number of exits serving the space. If the front door is blocked by a queued line at the host stand, the real distance is longer than the drawing suggests.
Maine path. A change of occupancy from mercantile to assembly, with a new occupant load of 148, is a plan-review event. Submit drawings to the Office of State Fire Marshal and to the local code enforcement officer before construction, showing the occupant load calculations, egress arrangement, hardware, and lighting. Fire alarm work, if required by the review, must be designed and installed by properly licensed persons, with a permit, submittal, and acceptance test.
The owner's six-week schedule is not the constraint that matters; the plan review and any required alarm installation will set the date. Advise submitting immediately and not ordering kitchen equipment until the review comments are in hand.