172. Once a fire has started, been detected and a warning given, everyone in the premises should be able to move or be assisted to move away from the fire to a place of reasonable safety such as a protected stair or other compartment. From there they should be able to continue to escape to an unenclosed safe area beyond the premises before being affected by fire or smoke. Sufficient means of escape should be provided for persons using the premises, both in terms of the number of escape routes and capacity and in terms of protection by enclosure from fire and smoke. Escape must also be considered from external areas like enclosed yards such as may be found in garden centres or DIY outlets.
173. Structural fire protection should also be considered to ensure that in the event of an outbreak of fire within the building, the load-bearing capacity of the building will continue to function until all occupants have escaped, or been assisted to escape, from the building.
174. The level of provision of means of escape and the fire protection that should be given to an escape route will vary depending on the level of risk within the premises and the occupants. In some small premises a single escape route may be acceptable, in other cases there should be at least two exits and independent escape routes from each storey of the premises. This will prevent a fire affecting more than one escape route at the same time. When determining whether premises have adequate escape routes, a number of interdependent factors should be considered, these are:
175. The people present in office, shop and similar premises will primarily be staff, visitors and customers and they will have been considered during the fire safety risk assessment. The escape time available will depend on a number of factors, including the number of escape routes available, the travel distance to be covered, the nature of the occupants, staff availability and the speed of fire growth.
176. The number and capability of people present will influence the assessment of the escape routes. The existing escape routes must be sufficient to enable the maximum number of people likely to use the premises at any time, such as during sales, to safely escape. The outcome of a fire safety risk assessment may necessitate an increase in the capacity of the escape routes or a restriction on the number of people in the premises.
177. In multi-occupied buildings, escape routes within premises should normally be independent of separately occupied premises; people should not have to go through another occupier's premises to escape as the route may be secured or obstructed. Where such independent escape is not possible, then a robust legal agreement may be required to ensure access at all relevant times.
178. Technical Annexes 13.3, 13.8 and 13.15 contain benchmarks against which existing provision can be compared.