A hall for a settlement is sized by the most demanding use, and the guide’s own allowances show that this is sleeping, not meeting: 100 people sleeping at 2 m² each need 200 m², more than the 100-150 m² main hall designed for meetings. The exits are sized separately: two doors of 1.2 m clear width can empty 150 people in roughly 64 seconds at typical flow rates, but only if both are kept free, open outward and never single-file bottlenecks.
Part of Community Gathering Hall
Sizing for settlement population is the calculation of a hall’s floor area and exit width from the number of people it must hold and what they will be doing.
The Floor Area Depends On The Activity
The gathering-hall guide’s allowances per person: 1.0-1.5 m² seated at a meeting; 1.5-2.0 m² at tables for dining; 0.5-0.7 m² standing; and 2 m² for sleeping on the floor in an emergency. It states that a settlement of 100 needs a main hall of about 100-150 m² and a total footprint of 150-200 m².
Worked Example: Area By Use And Population
Inputs: populations 100 and 150 (Dunbar’s number is the upper limit the settlement-layout guide plans for); allowances above.
| Use | 100 people | 150 people |
|---|---|---|
| Seated meeting (1.0-1.5 m²) | 100-150 m² | 150-225 m² |
| Dining (1.5-2.0 m²) | 150-200 m² | 225-300 m² |
| Standing (0.5-0.7 m²) | 50-70 m² | 75-105 m² |
| Sleeping on floor (2 m²) | 200 m² | 300 m² |
Each cell is population × allowance: for example 150 × 1.5 = 225 m² and 150 × 2.0 = 300 m².
- At the dining allowances a 100-150 m² hall seats only 50 to 100 people (100 ÷ 2.0 = 50; 150 ÷ 1.5 = 100), so 100 people dine in two sittings unless the hall is at the top of its range.
- For sleeping, the hall holds 100 ÷ 2 = 50 to 150 ÷ 2 = 75 people; adding the kitchen, store and small room (the total footprint of 150-200 m²) gives 75 to 100.
- For 150 people the main hall must be 150-225 m² for meetings, not 100-150 m².
So the guide’s sentence that the hall should shelter the entire population at 2 m² each is not met by its own sizing. Either enlarge the hall, accept that it shelters about half the settlement and hold the rest in houses and stores, or reduce the claim. The guide’s own figures disagree here.
Worked Example: Exits And Time
Model-code and fire-engineering values, not stated elsewhere in this corpus: egress width of about 5 mm (0.2 in) per person for level exits; a door’s effective width is its clear width less about 0.3 m; people flow through at about 1.3 persons per second per metre of effective width; a minimum of two exits above about 50 occupants; and doors serving about 50 or more people must swing in the direction of exit travel (the threshold differs between model codes, from 50 to 100). Check them against a current code before relying on them.
Inputs: 150 people; two doors, each 1.2 m clear (the guide’s stretcher width).
- Code width: 150 × 5 mm = 750 mm. One 1.2 m door exceeds it, so the hall still meets it with one door blocked.
- Effective width of one door: 1.2 − 0.3 = 0.9 m.
- Flow through one door: 0.9 × 1.3 = 1.17 persons per second.
- Time for 150 through one door: 150 ÷ 1.17 ≈ 128 s; through two doors: 150 ÷ (2 × 1.17) ≈ 64 s.
- Standing event of 240 (the floor-area maximum of a 120 m² hall): 240 ÷ 2.34 ≈ 103 s.
These are minimum times with unobstructed flow and no hesitation. Crowd density of 240 ÷ 120 = 2.0 persons per m² is far below the roughly 5 per m² at which crowd crush becomes a danger (a commonly cited crowd-science figure, also not stated elsewhere in this corpus), but the same crowd squeezing into one blocked door can reach that density at the door.
What You Need
- A target population and the layout it must be safe for
- At least two exits placed apart, on opposite ends or sides
- Doors that open outward and cannot be barred from inside
Method
Step 1: Compute the area for each use and each population, as in the table.
Step 2: Take the governing use and either size to it or write down the smaller capacity honestly.
Step 3: Size the exits for the largest crowd, keeping one blocked.
Step 4: Hang doors to swing outward, with a latch or bar that anyone can release from the inside in one motion without a key.
Step 5: Post the numbers by each door.
Common Mistakes
- Sizing the shelter capacity from the meeting area.
- Two doors side by side, so one fire or fall blocks both.
- Inward-opening doors: a crowd pressing out holds them shut. Crowd-crush deaths happen at inward-opening doors and single exits.
Safety
A hall is where the whole community is inside at once
Exit width, door swing and the number of exits are life-safety matters here, not conveniences. Never chain, bar or lock a hall door while people are inside, whatever the security concern (Defensive Architecture recommends drop bars; fit them so they can be lifted from inside). Keep both exits clear of stored furniture at all times.
What’s Next
- Learn next: Emergency Shelter Capability — what the sleeping figure means in practice
- Combine with: Large-Span Roof Structures — roofing the floor you have sized