Further guidance regarding escape routes
This section provides further guidance on the general principles that apply to escape routes and provides examples of typical escape route solutions for a range of common building layouts. The guidance is based on premises of normal risk so if your premises (or part of your premises) are higher (or lower) risk you should adapt the solution accordingly.Widths and capacity of escape routes and stairways
Once you have established the maximum number of people likely to be in any part of the premises, the next step is to establish that the capacity of the escape routes is adequate for people to escape safely in sufficient time to ensure their safety in case of fire. The effective usable width of an escape route is the narrowest point, normally a door or other restriction such as narrowing of a corridor due to fixtures and fittings. The capacity of an escape route is measured by the number of persons per minute that can pass through it, so to establish the capacity of a route, it is first necessary to measure the width of the route at the narrowest point. The effective width of a doorway when the door is open at right angles to the frame. The effective width at any other point is the narrowest clear unobstructed width through which people can pass.
The time available for escape depends on several factors. Studies of human behaviour in an emergency situation have shown that about two thirds of the time available to escape is taken up by the initial reaction to the developing situation. For example, people will decide whether the situation is real or false, often waiting to see the reaction of people around them, and generally gathering information to decide whether to act or not.
The final third is taken up by the actual movement away from the area of fire. Throughout this time the fire may be growing and spreading. Therefore to account for the limited available time for people to travel to a place of reasonable safety, the length of escape route needs to be restricted. The following guide can be used to determine the general capacities of escape routes;
A width of at least 750mm can accommodate up to:
- 80 people in higher risk premises.
- 100 people in normal risk premises.
- 120 people in lower risk premises.
A width of at least 1050mm can accommodate up to:
- 160 people in higher risk premises.
- 200 people in normal risk premises.
- 240 people in lower risk premises.
0845 528 0300
