Last edited 15 Dec 2017

Building evacuation

Building evacuation is the process of making sure everyone inside a building gets out safely and in a timely and controlled manner in the event of an emergency, such as fire. Buildings commonly use equipment such as fire alarms, exit signage, emergency lighting and emergency escape routes to facilitate evacuations.

In 1994, John Abrahams investigated building evacuation strategies and found that the independent variables were the building’s complexity and the mobility of the individuals. The strategy changes from ‘fast egress’ to ‘slow egress’ as the complexity increases and mobility decreases. At the end of this scale is the strategy of ‘moving to a safe place inside the building’ where help can reach the individuals. In most buildings, these ‘Safe Havens’ will be in the stairwell, and in areas with a particular risk of earthquakes, buildings may incorporate them on each floor.

A simultaneous evacuation is where building occupants react to the alarm and follow the designated means of escape to the place of safety away from the building. This may not be suitable or practicable for larger or more complex buildings due to the risks of congestion at escape routes. These buildings may be designed so that evacuation is initially limited to those nearest the hazard, before being extended if necessary to others. This type of phased evacuation strategy requires different alarm signals – a warning and an evacuation signal.

Complex or large buildings, or those with occupants who may be immobile, such as hospitals and care homes, may be sub-divided into different fire compartments to allow slower evacuation times. Public buildings such as cinemas and theatres may have a staff alarm which enables pre-arranged evacuation plans to be put into action.

The Regulatory Reform (Fire Safety) Order 2005 requires that owners of premises other than private dwellings appoint a responsible person who takes reasonable steps to make sure people can safely escape if there is a fire.

A fire marshal, also known as a fire warden, is an individual who is allocated, or who volunteers, to take on fire safety responsibilities for their organisation. In the event of an emergency, they must helping evacuate people from the building to assembly points, ensure they have a list of those who are normally present in the building, as well as the signing-in book, and carry out a roll-call to ensure everyone has left the building safely.

Approved document B, Fire Safety, Volume 2, Buildings other than dwellinghouses, defines means of escape’ as:

‘Structural means whereby [in the event of fire] a safe route or routes is or are provided for persons to travel from any point in a building to a place of safety.’

The approved document defines an escape route as ‘that part of the means of escape from any point in a building to a final exit’ where a final exit is ‘The termination of an escape route from a building giving direct access to a street, passageway, walkway or open space and sited to ensure the rapid dispersal of persons from the vicinity of a building so that they are no longer in danger from fire and/or smoke.’

Escape routes may involve protected corridors, lobbies or stairways which are protected from fire in adjoining accommodation by fire-resisting construction.

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