max-dwell-time-alert

---
name: max-dwell-time-alert
description: Works out the legal maximum number of people your dining and bar areas can hold, using the two calculations a fire risk assessment uses, floor space factor and exit capacity, and flags when a queue pushes the room toward that figure rather than an arbitrary "feels busy" guess. Never invents a capacity number: calculates one from the room's own measurements, taking the lower of the two results. Use when setting the maximum covers your space can hold, including a waiting area where guests queue.
---

# Know the room's legal limit before the fire warden does

Give it the floor area of each space by its use, and the clear width of each exit. Get back occupant capacity calculated both ways, the lower figure that is the actual limit, and a flag for any queue practice that lets the room run past it.

## What it does

1. **Calculate occupant capacity two ways, then take the lower.** "The first uses floor space factors... the second identifies an exit capacity." The rule: "The lowest figure of the two calculations determines safe occupancy."

2. **Use the floor space factor for how the space is used.** 1.0m² per person for "Dining rooms, Seated Lounge/Bar, Restaurants, or similar", 0.5m² for a standing bar, 0.3m² within 2m of the serving point. With fixed seating, the limit is "known from the number of seats provided."

3. **Calculate exit capacity from clear width**, discounting the largest exit where exits sit close together. A 1050mm exit allows up to 240 at low risk; each extra 75mm adds 15 more.

4. **Take the duty seriously.** The operator "will need to calculate the occupant capacity as part of your fire risk assessment." A worked example: a café with "a safe occupancy figure of 250 individuals... which is often full to capacity."

5. **Point the figure at the queue, not just the dining room.** A waiting area is subject to the same floor space factor and can breach its own limit first.

6. **Alert on approach, not breach.** Flag at a stated margin (e.g. 90%) of calculated capacity, so staff slow the queue before the legal limit is reached.

## Then it checks

1. Both calculations are shown for every space, with figures used.
2. The lower figure is recorded as the limit, never the higher.
3. Any discounted exit states why.
4. The queue or bar area has its own calculated limit.
5. An approach-margin alert threshold is stated.

Any check fails: redo that step once. Failed twice: say what is wrong and stop.

## Rules
- Public information only. Never invent a fact, number or quote. Anything sent in someone's name says whose name it is.
- Never state a capacity without showing both calculations and which was lower.
- Never treat a generic number as this venue's figure.
- Working document for a fire risk assessor or local fire and rescue service to verify. Not a substitute for a fire risk assessment.

## Built from
- GOV.UK, "Reasonable expectation of numbers of individuals present", gov.uk/government/publications/terrorism-protection-of-premises-bill-2024-factsheets, read 4 Nov 2026: steps 1 and 4.
- Nottinghamshire Fire and Rescue Service, "Occupancy calculations", notts-fire.gov.uk/business-fire-safety/fire-risk-assessment/occupancy-calculations, read 4 Nov 2026: steps 2 and 3.

# max-dwell-time-alert

## You are given
A list of spaces (`dining room`, `bar`, `waiting area`), each with: floor area in m², use category (`seated dining`, `bar seated`, `bar standing no seating`, `within 2m of serving point`, `fixed seating with known seat count`). The clear width in mm of every exit, and whether any two sit close enough that one should be discounted (judged by Claude). The approach-margin percentage to alert at (e.g. 90%), set by the owner. A live or sample headcount per space, with timestamp, if available.

## Produce
Write into a `./max-dwell-time-alert-output/` folder:

1. `floor-space-capacity.csv`: `space_name`, `area_m2`, `use_category`, `factor_m2_per_person`, `calculated_capacity`, `fixed_seat_count`, `capacity_used`. `factor_m2_per_person` is `1.0`, `0.5` or `0.3`, blank for fixed seating. `calculated_capacity` is `area_m2` divided by the factor, rounded down. `capacity_used` is `fixed_seat_count` where supplied, else `calculated_capacity`.
2. `exit-capacity.csv`: `space_name`, `exit_ref`, `clear_width_mm`, `risk_category`, `base_capacity`, `discounted`, `discount_reason`, `exit_capacity_contribution`. `exit_capacity_contribution` is 0 where `discounted` is `yes`.
3. `occupant-capacity.csv`: `space_name`, `floor_space_figure`, `exit_capacity_figure`, `occupant_capacity_limit`, `which_was_lower`. `occupant_capacity_limit` is the lower figure.
4. `headcount-alerts.csv`: `space_name`, `timestamp`, `headcount`, `occupant_capacity_limit`, `percent_of_limit`, `alert_level`. `alert_level` is `normal` below the approach margin, `approaching limit` up to 100%, `at or over limit` at or above it.
5. `gaps.md` - a numbered list of: any space with no exit width supplied; any discount with no reason recorded; any `at or over limit` row; any space missing a use category.

## Rules
- Codex calculates and records. It never decides which exits to discount, the approach-margin percentage, or a space's use category; those are supplied by Claude or the owner.
- Figures are calculated exactly, never estimated; `calculated_capacity` is always rounded down.
- Never report an occupant capacity without showing both figures it was chosen from.
- Use British English and DD Month YYYY dates. No em dashes; flag any supplied text containing one in `gaps.md`.
- Every file ends with: this is a working document for the owner to check against their current fire risk assessment, and for a fire risk assessor or fire and rescue service to verify. Not a substitute for a fire risk assessment.

## Return
Each file's absolute path and row count. The occupant capacity limit per space, and which figure was lower. Exit capacity contribution per space and any discounted exit with its reason. Every headcount row at `approaching limit` or `at or over limit`. The `gaps.md` item count.