THE FORMULA FOR CALCULATING THE MAXIMUM OF PERSONS
THAT CAN SAFELY USE OR OCCUPY YOUR VILLAGE HALL
These calculations will provide you with guidelines when you are calculating the maximum number of persons permitted to ‘safely’ use the main hall & balcony. These figures are based on the Communities & Local Government’s (CLG’s) Guidance Publication ‘Small and Medium Places of Assembly’ & the Current Building Regulations Appendix C.
These two documents were issued as guidance for those persons carrying out their Fire Risk Assessment of the village hall, as required under the Regulatory Reform (Fire Safety) Order 2005.
Note: These calculations will also apply to any balconies forming part of the main hall when used by all persons.
The first step is to measure the internal useable floor area of the main hall but excluding the stage area at this time. Where stages are stored in side rooms and erected for specific occasions, the useable floor area calculations will have to be adjusted.
(The only time you would include the stage area is, if the stage is used for a large number of persons seating or standing).
The total calculable useable floor area should be worked out in squ metres.
a) Numbers & Widths of the Exit Doors;
Next step is to identify all the access and egress doors to and from the hall; i.e. single, double or triple width doors, (There are very few triple width fire exit doors found in village halls), Next establish if they all open outwards from the hall to either open air or, into a corridor(s) which lead directly to a fire exit door leading out of the building.
b) Calculating the Numbers of Persons Passing through the Exit Doors
Fire Exit doors are designed in ‘Units of Exit Widths’. A unit of exit width is 21” or 545mm wide. This figure is based on the average width or distance across an adult person’s shoulders.
Each unit of exit width will permit 40 persons per minute to pass through, a single width exit door, a door should not normally be less than 2ft 6ins (750mm) wide.
A set of double doors (minimum 1050mm) will permit the passage of 80 persons per minute to pass through, providing all the other exit doors and staircases on the exit route, leads out of the building, providing the final exit doors are not less than 1050mm wide. Where there are initially double doors leading out of a hall into a corridor that leads directly to a single width fire exit door, we have what the Fire Service calls the ‘Bottle Neck’ effect. Your calculation for exiting the hall must then be based on a single width fire exit door calculation not the double doors from the hall.
Calculating for the loss to a Fire Exit Door & Route not being available due to Fire;
It is the calculation practice to first select the widest set of exit doors, these doors are then discounted as the doors & escape route may not be available due to smoke and or fire affecting this entire escape route.
We are then left with the remaining door(s) to calculate how many people will be able to escape per minute using these doors (See b) above).
Evacuation Time from the Village Hall (The time it will take to evacuate all persons from the hall);
The construction of your village hall will determine how quickly all persons must be able to evacuate to the outside. There are very few village halls which will have a staircase from any upper floor that is totally enclosed in fire resisting materials to the same standards as you would find in a hotel or offices with upper floor levels.
The evacuation times for village halls will be divided into 3 time categories.
i) An all light weight totally combustible construction (Using the old style Scout Hut construction):- 2 minutes maximum for evacuation.
ii) Traditional brick & stone walls with plaster internal partitions and ceilings with timber floors and staircases:- 2.5 minutes for evacuation.
iii) Traditional current day substantially built all non combustible construction, built to modern Building Regulations standards:- 3 minutes for evacuation.
With the common day to day uses of the village hall, it is anticipated that on most occasions all persons using the hall will be able bodied and reasonably disciplined in fire safety procedures. Persons with any mobility or impairment needs that are permitted onto the premises, it will be the Hall’s Managements responsibility to carry out a separate assessment when those occasions arise.
The Calculating the Maximum Number of Persons who can occupy a floor space – (Building Regulations Appendix C)
The following calculations should be based on having either a seated audience, predominantly standing only or, for modern dancing. (Traditional dancing will require a greater floor space per person).
a) Persons standing: The floor area allocated per person is .03 m squ – .5m squ.
b) Seated persons: The floor area occupied for seating is .5 m squ per person without fixed seating. For fixed seating you will need to allow1.0 m squ per person.
The width between rows in fixed seats, there should be a clear space of at least 305mm between the back of one seat and the front of the seat behind it.
You also have to take into consideration, the number of and width of gangways- centre aisle and down the two sides of the hall. Gangways should be at least 1.05m wide. (You may not be able to have lines of chairs the full width of the hall). In general, no seat should be more than 7 seat widths away from a gangway. If temporary seating is provided, the seats should be secured in lengths of not fewer than 4 seats and not more than 12 seats. Each length should be fixed to the floor.
Standing and sitting in gangways, or in front of fire exit doors should not be permitted.
c) For Modern Dancing: the calculation would be .5 m squ per person.
e) On those occasions when a Village Hall is used for exhibitions, sale of work, wedding parties etc,
The area occupied by each person should be increased to 1.5m squ, at the same time ensuring that the positioning of tables, exhibition and display stands etc, maintain the minimum width of the gangways to not less than the width of the fire exit doors.
Summary Maximum Occupancy Recommendations:
To summarise; Calculating the number of persons you can safely accommodate will be based on:
A) The construction of the building,
B) The time to evacuate the hall,
C) The width and number of available fire exit doors and routes (less the widest set),
D) The density factor i.e. per squ m per person.
E) For seated audiences take into account the width of the rows and the number and width of gangways.
Note: Persons in the hall with any special mobility & impairment needs will require a separate re-assessment of the situation.
Copyright H. Paviour.
Revised; December 2009.
Note: I am indebted to Harry Paviour for this information. Harry is a retired senior fire officer and is happy to help halls where they need specialist advice. Contact the Dorset Village and Community Halls Advisory Service for more information.