It was first published in 2008, when it part-superseded BS 5588 Fire precautions in the design, construction and use of buildings, parts of which are still relevant to residential buildings. It also replaced DD 9999 Code of practice for fire safety in the design, construction and use of buildings.
External escape routes are wholly or partially open to the external air therefore the risk of smoke logging is reduced compared with enclosed escape routes inside the building. External escape routes include external escape stairs, access decks and flat roofs. In certain circumstances, an escape route from a building may be by way of a flat roof or an access deck.
shop sales areas other than those listed in sub-clause 2(b) including supermarkets and department stores (all sales areas), shops for personal services such as hairdressing and shops for the delivery or uplift of goods for cleaning, repair or other treatment or for members of the general public themselves carrying out such cleaning, repair or other treatment
In the case of a building which has only 1 direction of travel, the travel distance should be measured to a protected door giving access to an escape stair or a place of safety. In the case of a building or part of a building where there are at least 2 available directions of travel, the travel distance may be measured to any protected door.
In progressive horizontal evacuation, occupants within separate compartments remote from the fire may not need to evacuate the building. They may be able to remain within the building until the fire and rescue service has dealt with the fire or, if required, commence evacuation into an adjoining compartment or escape direct to the outside. The objective is to provide a place of relative safety within an adjoining compartment, from which further evacuation can be made if necessary but under less pressure of time.
if the compartment does not contain either a final exit or direct access to a protected zone, then each of the adjoining compartments, should have at least 1 other escape route, which is not through a further compartment, and
To assess the numbers of exits required from the storey, the occupancy of the whole storey must be assessed. There is no need however to include adjoining parts of the building where the adjoining part does not communicate with the part under consideration.
Single escape stair - it is possible to design a building with part of the upper storey at a height of not more than 7.5m to have only one escape route where the remainder of the storey has two escape routes. In cases where escape is by way of a single escape stair, access to the escape stair should be by way of a protected lobby.
any room on a storey at a height of not more than 7.5m where the escape route provides access to a place of safety or to another compartment and the travel distance is designed in accordance with the guidance in clause 2.9.3 for one direction of travel.
The guidance on the width of exits assumes a unit width of 530mm per person and a rate of discharge of 40 persons per minute. In theory a corridor 530mm wide would be capable of discharging 100 occupants in 2.5 minutes, but such a width would not allow occupants to move around freely and without difficulty, to the best of their ability. The unobstructed width of each individual escape route should be at least 1200mm to assist occupants with sensory, cognitive and/or mobility impairments. However where only stepped access is provided to a part of the building, the escape route may be reduced as follows:
Fixed seating or furnishings - in a building, or part of a building, with fixed seating or fixed seating and fixed tables or other floor fixtures, there should be access to an exit by way of a gangway or a seatway, or a seatway directly to an exit; or a circulation area in accordance with the table and diagram below and:
in the case of shops where the room, or part of the room, has an occupancy capacity of more than 100, the minimum width of a circulation area should be designed as if the circulation area were an escape route, or
In residential buildings occupants are particularly vulnerable to fire when asleep. Occupants may also be unfamiliar with their accommodation and escape routes. Those occupants on the fire floor should be provided with the opportunity to reach a protected zone (or other escape route) in relative safety and as quickly as possible, therefore, the movement of fire and smoke to the escape route should be inhibited.
In the event of a fire, there is always a risk that an opening in a floor could result in a proportion of fire or smoke and toxic fumes arising from a fire flowing up through the opening leading to a build-up of smoke on the upper storeys. This can pose a threat to life safety, particularly when the occupants are unfamiliar with the building. Smoke and flames rising through such an opening in a floor may impede evacuees from leaving the building. It is important when such a design is considered that it does not impair the ability of the occupants to escape. Occupants should be able to move directly away from the opening or continue their evacuation at a safe distance away from the edge of the opening.
Doors across an escape route can slow the flow of occupants and may lead to crowding. To ensure that doors on an escape route do not unduly delay escape they should open in the direction of escape. However doors across an escape route may open against the direction of escape where the occupancy capacity in the building, or part of the building is low as follows:
For the purposes of compliance with this standard a gallery is an integral part of the room into which it projects, and the occupants of a gallery would have the same awareness of an outbreak of fire in a room as the other occupants of that room. The limitations on the size of a gallery relative to the room into which it projects is to provide those occupants on the gallery with the same awareness of any outbreak of fire.
A gallery should be open above and below to the room into which it projects and should not give access to any other room, other than a room with a means of escape independent of the gallery. The gallery may be wholly or partly enclosed below, where:
Where an exit door from a room, storey or a door across an escape route has to be secured against entry when the building or part of the building is occupied, it should only be fitted with a lock which is readily operated, without a key, from the side approached by occupants making their escape. Similarly, where a secure door is operated by a code, combination, swipe or proximity card, biometric data or similar means, it should also be capable of being overridden from the side approached by occupants making their escape (see also electrically operated locks).
In buildings, or parts of buildings, that are not open to the general public, such as in offices or other working environments, the occupants should be awake and familiar with the building. When staff in such areas are trained both in the emergency procedures and in the use of the specific emergency devices fitted (see clause 2.0.8) then emergency exit devices to BS EN 179: 2008 can be installed. This type of locking device is released mechanically by a single action applied to the door lever handle or push pad to allow people familiar with the building to escape in an emergency.
In a building containing an auditorium, a ventilation system should be provided above all stages so that in the event of fire the occupants can escape before being overcome by the effects of fire or smoke. The ventilation system should be designed in such a way that the direction of air movement in the event of fire is from the auditorium towards the stage. Ventilation may be provided by means of mechanical extract ventilation or by natural ventilation direct to the external air, additional guidance is provided in BS 5588: Part 6: 1991.
Each case should be considered separately to ensure that smoke will not be transferred from one area to another, particularly where there are distinctly separate entertainment areas, which share common escape routes.
an occupancy capacity of more than 60 but not more than 100 and at least 1 route of escape is by way of a protected zone, an external escape stair or to another compartment. Where the occupancy capacity is more than 100 the escape stair should be enclosed within a protected zone.
It is important that ducted heating and ventilation systems including air conditioning systems, installed to maintain interior environment conditions, that serve the building should not transfer fire and smoke to or from; any compartment to any other compartment, escape route, common space, roof space or other concealed space. Therefore, in the event of an outbreak of fire, the system should automatically either shut off, or operate in smoke control mode. For more detailed guidance refer to BS 5588: Part 9: 1999.
The junctions between protected routes of escape (see clause 2.0.6) and other parts of the building are vulnerable to fire and smoke. This is because fire and smoke can penetrate weaknesses at junctions which could compromise the means of escape. The designer should consider detailing at junctions to inhibit fire and smoke spread into the protected route of escape.
Where part of a building is a protected route of escape and forms a junction with any other part of the building including for example, an external wall, a separating wall, another compartment wall, or any other wall or screen forming a protected route of escape, the junction should maintain the fire resistance duration of the more demanding guidance.
Every escape stair should be wide enough to accommodate the number of occupants needing to use it in an emergency and allow them to make their escape before being overcome by the effects of fire and smoke. This width will depend on the number of stairs provided and whether the escape strategy for the building (or part of the building) is based on: 2b1af7f3a8