Alternative escape routes There is always the possibility of the path of a single escape route being rendered impassable by fire, smoke, or fumes. Ideally, people should be able to turn their backs on fire wherever it occurs and travel away from it to a final exit or protected escape route leading to a place of safety. However, in certain conditions, a single direction of escape (a dead end) can be accepted as providing reasonable safety. These conditions depend on the use of the building and its associated fire risk, the size and height of the building, the extent of the dead end, and the number of persons accommodated within the dead end. The Ultimate Place of Safety is the open air, clear of the effects of fire. In large complex buildings, reasonable safety may be reached within the building, provided suitable planning and protection measures have been put in place. All persons within the premises should be able to reach a place of ultimate safety, before any life-threatening conditions arise, either unaided or with the assistance of staff but without any assistance from external agencies (such as the Fire Rescue Service Places of Relative Safety . It is often necessary to devise a temporary place of safety, such as when evacuating high buildings. This may be defined as a place of comparative safety and includes any place, which puts an effective barrier (normally 30 minutes fire resistance) between the person escaping and the fire. Examples are as follows:
• A storey exit into a protected stairway or to the lobby of a lobby approach stairway • A door in a compartment wall or separating wall leading to an alternative exit • A door, which leads directly to a protected stair or a final exit via a protected corridor
A staircase, which is enclosed throughout its height by fire-resisting structures and doors, can usually be considered to be a place of comparative safety. In these cases, the staircase can be known as "a protected route".
Requirements for the escape stairs, passageways, and doors Within the various building regulations there are in principle two defined types of stairways: 1. The accommodation stairways (a stairway, which is provided for the convenience of occupants, in addition to that or those required for escape purposes) and the type that concerns more so for this element. 2. Escape stairs or protected stairways are defined as a stairway, which is adequately protected from fire in adjoining accommodations by fire-resisting construction and either discharge through a final exit or a protected route leading to a final exit. The following tables have been taken from the (England and Wales) Building Regulations.
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