Seating should be securely located in position to avoid gangways and exits being obstructed by displaced and overturned seats, especially in a hurried evacuation.
Maximum travel distances
|Available direction of escape||Areas with seats in rows||Open areas|
|In one direction only||15||18|
|In more than one direction||32A||45B|
- A - this may include up to 15m in one direction only
- B - this may include up to 18m in one direction only
Fixing of seats for closely seated audiences
Seating may be permanent or temporary depending on the use of the area, but the recommendations for layout and gangways apply in either case.
Where the seating layout is permanent, all seating (except for chairs in boxes and similar small enclosures) should be firmly fixed to the floor. All seats on telescopic or retractable units and tiered platforms of any type should also be securely fixed.
- Retractable or telescopic seating (normally used in a multi-purpose hall or sports arena). This may be a fixed installation drawn out from the surrounding enclosure or the whole unit may be moveable to form a number of seating layouts. Retractable or telescopic seating, when in the extended position, should be provided with locking devices to prevent movement
- Demountable seating. This comprises tiered seating assembled from kits of parts and disassembled after use
- Rows of portable seating. This may be provided in the activity area of a sports arena or on the open space of a multi-purpose hall and may be provided on a structure to provide satisfactory sightlines.
Recommendations for temporary seating
Seating for more than 50 persons laid out on the floor area should be secured together in lengths of not fewer than four seats and no more than 14 seats. Where seats are fixed together it should not be possible to separate them nor for a row of chairs to “snake” merely by pushing one or more seats in the row. Due to room constraints, it may not always be possible to fix chairs to the floor; however, seats should be tied/fixed together based on the above.
Where the fixing of seating to the floor is impractical or undesirable (such as on polished dance floors) the use of floor bars instead of floor screws may be permitted. Such floor bars should not be more than 25mm in height, have a cambered top surface so as to avoid the risk of tripping persons using the seatways, and should extend from the row to be fixed to at least two adjacent rows, but should not extend across any gangways.
If seating for more than 250 persons is required, provision should be made for fixing to the floor the rows of seating flanking the front, the back and the cross gangways and the seats near exits, although only the end seats of the rows need to be fixed to the floor if all the seats are secured together.
Where seats are secured together, it should not be possible to separate them, nor for a row to “snake”, merely by pushing one or more seats in a row.
Seating and gangways should be arranged to allow free and ready access direct to the exit. Audiences seated in rows will first have to make their way to the end of the row before being able to use the escape routes provided. However, in general, no seat should be more than 7 seats away from a gangway/exit route unless the distance between rows of seats, the seatway is increased in accordance with the table below.
The number of seats in a row should not exceed:
|Seatway (mm)||Maximum number of seats in a row/gangway on one side||Maximum number of seats in a row/gangway on two sides|
|300 to 324||7||14|
|325 to 349||8||16|
|350 to 374||9||18|
|375 to 399||10||20|
|400 to 424||11||22|
|425 to 449||12||24|
|450 to 474||12||26|
|475 to 499||12||28|
|500 or more||12||Limited by the travel distance|
- Gangways should be not less than 1.05m in width and there should be no projection.
- The ends of all rows and seats should be so aligned as to maintain uniform width of gangway throughout its length.
- The clear seatway should be measured between the back of one seat and the maximum projection of the seat behind when that seat is in the UP position.
- If disabled persons sit in their wheelchairs as part of the audience, the wheelchairs should be placed in a position where they will not obstruct other people in an emergency and where a ready means of exit is available.
- When wheelchair users are present, no exit should have a clear opening width of less than 900mm.
- When a disabled person leaves their wheelchair to occupy a seat, the wheelchair should be left readily available such that it will not cause an obstruction to an exit route.
Calculating the safe occupant capacity of premises at any given time
The maximum safe occupant capacity within a premises depends on a number of factors, these include:
- the total available floor area and its use
- the number of available exit doors
- the actual distance people need to travel to reach the nearest exit door
- the width of doors and escape routes
- the method of opening doors and the direction in which they open
- the number of persons likely to use each door.
To determine the maximum safe capacity for a particular room/area, the following step by step method should be followed:
- Measure each room/area in square metres.
- Areas occupied by fixed furniture, including seating, pool tables, stages and bar serveries should be excluded from the calculation.
- From this figure, a safe capacity can be determined by allowing 1m2 per person for restaurant/dining areas and 0.5m2 per person for standing areas.
- Add to this figure the number of fixed seats and the number of staff/performers who may be present behind the bar, serveries or on stage.
Determine the number of exits required for the calculated safe capacity, as follows:
- Up to 60 persons – At least one 750mm width exit. The door may open inwards or outwards.
- Up to 100 persons – At least two 750mm width exits. All doors to open outwards.
- If two exits are provided but a door opens inwards, the safe capacity is restricted to 60 persons.
- Up to 200 persons – At least two 1050mm width exits, or at least three 750mm width exits. All doors to open outwards,
- Where the number and size of exits do not accommodate the potential safe capacity calculated in step 1 either:
- additional exits need to be provided
- the reduced safe capacity allowed by the number and size of existing exits used.
Check that each of the following conditions applies:
- Where there is only one exit available no person should have to walk more than 18m to reach it.
- Where there are two exits available but there is a portion of the room/area from which one exit has to be passed to reach the alternative, no person should have to walk more than 18m to reach the nearest exit.
- Where there are two or more exits they should be sited far enough apart to ensure that if one is unavailable due to fire the other remains available.
- For occupancies up to 60 persons, exit doors should be either free swing or be fitted with a single simple opening mechanism, which does not require the use of a key (for example, normal door handle or push pad device.)
- Emergency exit doors for occupancies exceeding 60 persons should be either free swing or be fitted with an emergency push bar device, which has an operating mechanism over at least 60% of the door width.
- Where an exit door serves two adjacent rooms/areas, such as via a draft lobby or corridor to the final exit door, the width of the corridor and door should be adequate for the combined occupancy of both areas.
- Where an escape route passes through corridors, alleyways or past obstructions, the narrowest part of the route should be at least equal to the required door width for the number of persons using it.
- Where seating at tables is provided, clear gangways, minimum 750mm wide, should be maintained to facilitate evacuation.
- An enclosed outside area should be treated as a room, and as such the safe capacity of the area should also be calculated as above.
The fire service should be consulted if:
- the potential safe capacity calculated exceeds 200 persons
- any of the conditions under Step 3 cannot be met.
The safe capacity of each area must be kept under review and where any changes occur the figure must be re-assessed.