The LWF Blog
Fire Safety for Facilities Management Personnel – Means of Escape – Part 125
November 22, 2021 12:53 pmLawrence Webster Forrest (LWF) is a specialist fire engineering and fire risk management consultancy whose aim is to give information on best practice in fire safety for facilities management personnel through this blog series. In part 124, LWF discussed floor space factors when calculating occupant capacity for means of escape. In part 125, we continue discussing means of escape by looking at the three stages of escape.
The Three Stages of Escape
In a fire situation, building occupants are considered to go through three stages of escape. They are:
Stage 1 – travel within rooms
Stage 2 – horizontal travel to a storey exit or final exit
Stage 3 – vertical travel down stairs to a final exit
All elements must be assessed fully in order to design acceptable means of escape provision.
Stage 1: Travel within rooms
When designing means of escape for building occupants from the room they may be in at the time of a fire, there are various considerations.
The contents of the room (furniture etc.) should be arranged and kept so there is free access to exits.
Travel distance should be measured from any point within the room to the exit of the room for the first stage.
A large room, often defined as one which will accommodate 60 persons or more, usually requires more than one exit. This is to ensure that if an exit is blocked by fire, there is an alternative escape from the room. In this case, the 45 degree rule applies to those exits, but as a rule of thumb, the exits should not be so close together that they could be classed as one exit and, potentially, both be inaccessible due to fire.
The flammability of wall and ceiling linings should be restricted to as to avoid fire spread.
When considering inner rooms and means of escape, certain conditions should be met. Inner rooms must be given a clear vision panel between itself and the access room to allow occupants of the inner room to see a fire in the access room.
An alternative to full walls with clear vision panels installed is to provide a space between the top of the partitions between the inner and access rooms or to provide automatic smoke detection in the access room to give early warning of fire to occupants of the inner room.
It is not permissible to have an inner room within another inner room.
The access room must not be an area of high fire hazard.
In part 126 of this series, LWF will continue to discuss means of escape and stage one of the three stages of escape. In the meantime, if you have any queries about your own facilities or wish to discuss this blog series, please contact LWF on freephone 0800 410 1130.
Lawrence Webster Forrest is a fire engineering consultancy based in Surrey with over 25 years’ experience, which provides a wide range of consultancy services to professionals involved in the design, development and construction and operation of buildings.
While care has been taken to ensure that information contained in LWF’s publications is true and correct at the time of publication, changes in circumstances after the time of publication may impact on the accuracy of this information.