Chapter 7: Provision And Use Of Means Of Escape
194. Once a fire has been detected and a warning given, everyone in the premises should, if necessary, be able to move or be assisted away from the fire to a place of reasonable safety such as an enclosed protected stair or another compartment from where they should be able to continue to escape to an unenclosed safe area beyond the premises. Means of escape is the provision of safe escape routes for people to travel from any point in a building to an unenclosed safe area, and includes the measures to maintain those routes. The number and capability of people will influence the assessment of the escape routes. The escape routes must be sufficient to enable the maximum number of people likely to use the premises at any time to safely escape.
195. Escape must also be considered from external areas like enclosed yards.
196. Means of escape should be provided both in terms of the number and capacity of escape routes and in terms of their protection from fire and smoke. When determining whether premises have adequate escape routes, a number of interdependent factors should be considered, including:
- the characteristics, number and location of people in the premises
- the construction of the premises and the potential for fire and smoke spread
- the fire compartmentation of the premises
- the time it will take people to escape
197. A room containing more than 60 persons should have at least two exits, a room with more than 600 should have at least three exits. But a greater number of exits may be necessary, this will depend on the actual numbers resorting and travel distance to the nearest room exit.
198. Even where the number of persons is low, at least two escape routes may be necessary from:
- a storey over 7.5 m in height (other than flats, maisonettes and small premises)
- a basement used by the public (other than only toilets)
- a basement more than 4.5 m deep
- a flat entered from above the accommodation level
199. Larger premises will normally have at least two independent escape routes from each storey of the premises used for sleeping accommodation.
200. The direction of travel of alternative escape routes from any point within a room should:
- diverge at an angle of at least 45 o; or
- after a single direction of escape not more than 12 m, then diverge at an angle of at least 45 o plus 2½ o for every metre travelled in the single direction.
201. Escape routes should be via a direct and unobstructed route. Once occupants have left a room they should ideally not have to pass through another room to reach a protected escape route or a place of safety. Though in existing low risk situations, escape may be from an inner room through an outer room. (see paragraph 211)
202. An escape route should not be by way of
- a lift (unless specifically designed for evacuation)
- an escalator
- a manual sliding door, other than one to which the general public does not have access
- revolving or automatic doors unless arranged to fail safely in the outward opening position in accordance with BS 7036
- a window.
203. A clear headroom for escape routes and circulation areas is at least 2 m, and not less than 1.9 m in a doorway.
204. The width and geometry of escape routes should be sufficient to facilitate the evacuation method used and for the number of occupants to escape. From a room or storey with not more than 100 persons, an escape width not less than 1000 mm may be adequate. Where in excess of 100 persons, 1100 mm may be adequate. At least 1200 mm may be necessary where the room or storey is accessible to wheelchair users.
205. An escape route will not normally narrow in the direction of escape but at doorways the width can generally be 150 mm less than the escape route. Where the number of people using the escape route is not more than 225, the door width may be at least 850 mm where the number of people is not more than 100.
206. To assist with evacuation, a door across an escape route should open in the direction of escape where the occupancy capacity is 60 or more, or where occupants may need to exit quickly or the door is a final exit. In other situations it is good practice for a door to be outward opening if practicable.
207. The area outside final exit doors should have suitable underfoot conditions for persons evacuating and pathways so that persons can move away from the building.
208. There should be a limit on the distance that persons should have to travel to reach a place of reasonable safety. In general, travel distance is the distance measured along the actual route of escape (having regard to the layout) from any point within a storey to the nearest door giving direct access to either; another compartment; a protected stair; or to a final exit. However in the case of flats and maisonettes, two separate travel distances are considered:
- the distance travelled within the flat or maisonettes to its main entrance or exit door
- the distance travelled from the main entrance or exit door of a flat or maisonette to the final exit, protected escape route or external escape stair.
209. Travel distance benchmarks are given in Table 7.
Table 7 Travel distance by reference to building type
|Height||Description||Single direction of travel (m)||More than one direction of travel (m)*|
|Flats and Maisonettes|
|Within flat or maisonette||NA||NA||15||32|
|From flat or maisonette door||Not more than 7.5 m||Single exit||7.5||32|
|With alternative exit||unlimited||unlimited|
|More than 7.5 m||Single exit||7.5||32|
|With alternative exit||32||unlimited|
|Any height||open access deck or open access balcony serving accommodation||40||unlimited|
* this includes the single direction distance
210. A single direction of escape is travel before there is the choice of escape routes. See Figures 4 to 6. A single direction of escape may involve persons moving towards or past a fire, if the fire occurs between the occupant and the choice of escape routes.
Figure 4 - Single direction of escape within a room before a choice of escape routes becomes available
Figure 5 - Single direction of escape out of room and along a corridor before a choice of escape routes becomes available
Figure 6 - Single direction of escape within a room before a choice of escape routes, one of which goes through a fire door into another compartment
211. An inner room is a room where access to a circulation area can only be achieved by passing through an access room (see Figure 7). A fire could develop unnoticed in the access room preventing the occupants of the inner room escaping. The risk to persons in the inner room will be less if the access room contains limited combustibles and ignition sources, and travel distance from any point in the inner room to the exit from the outer room are short. The following conditions will limit the risk to persons in the inner room:
- where the inner room is used as a bedroom
- the access room should not be of a higher fire risk than the inner room and should contain limited combustibles and ignition sources
- a smoke detector should be provided within the access room and be capable of providing a warning of fire to persons within the inner room
- the maximum travel distance from any point in the inner room to the exit from the access room should not exceed 15 m, unless there are alternative exits from the access room
Figure 7 - Inner room arrangement
212. To protect escape routes from fire, the normal standard for escape stairs is for stairs to be enclosed within a fire resisting enclosure (creating a protected zone) such that the enclosing structure between the stair and the rest of the building has fire-resistance and any door in the enclosing structure is a self-closing fire door. This arrangement is shown in Figure 8. Each escape stairs should have its own independent final exit.
Figure 8 - Protection of escape stairs
213. If the enclosure has an external wall that projects beyond the face of a building or is set back in a recess, the route may be vulnerable should fire break through an adjacent window, door or other opening. Radiated heat or flames from the fire may impede escaping occupants. Therefore an external wall of a building which makes an angle less than 135 o with the external wall of the enclosure might need to be fire-resisting.
214. The width of an escape stair should be at least the width of any escape route giving access to it. A check should be made that the width of an existing escape stair is suitable for the persons who would use it and the method of evacuation. The number and capacity of stairs serving a building needs to be sufficient for the number of persons to allow the occupants of all storeys to evacuate at the same time.
215. Where part of a building has only one escape route by way of an escape stair, if access to the escape stair is by way of a protected lobby, this will provide an additional barrier to fire and may afford people additional time to escape. A protected lobby is where there are two self-closing fire doors between the adjoining accommodation and the stair.
216. Access to any escape stair which serves a storey at a height of more than 18 m should be by way of a protected lobby.
217. Where an escape stair also serves a basement storey, a self-closing fire door at ground floor level separating the basement stair enclosure from the stair enclosure serving the rest of the building will provide improved protection to the means of escape from any fire that may start in the basement.
218. Ideally, an escape stair (including landings) and the floor of a protected lobby will be non-combustible. Where an existing escape stair is combustible, consider the potential for the stair to be directly affected by fire, such as a fire occurring in an under-stair cupboard, and the possibility of lining the underside of the stair with non-combustible material.
219. A small room, reception, cupboard or toilet may be sited within the enclosure of an escape stair if the fire risk is low and all other parts of the building served by the escape stair have at least one other escape route.
220. The evacuation speed of people with mobility disability can be slow and there may be a space within the protected stair so that they can wait temporarily until it is safe to use the stair – a space capable of accommodating a wheelchair and not less than 700 mm x 1200 mm. These spaces should not be used for storage. Modern buildings may have an emergency voice communication system in the temporary waiting space to assist the escape process and reduce the anxiety of occupants making use of the space.
221. An external escape stair may present problems for persons evacuating a building because people can feel less confident using an unenclosed stair at a height. For this reason, an external escape stair may only be suitable where the topmost storey height is not more than 7.5 m; and the stair is used only by those who can safely use it. Appropriate weather protection may be necessary to enable the stair to be used in all weather conditions.
222. An external escape stair should lead directly to a safe area beyond the premises and should be non-combustible.
223. An external escape stair may be unusable if fire occurs in the building. External stairs with a rise more than 1.6 m, may need to be protected against fire from within the building with at least 30 minutes fire-resistance.
Escape across Flat Roofs
224. Where the occupants of premises can safely use it, an escape route may be across a flat roof, and be an alternative additional provision to another escape route.
225. The following criteria apply to an escape route across a flat roof:
- be clearly defined, illuminated and guarded with protective barriers not less than 1.1 m in height
- have a slip free surface
- have fire-resistance for a distance of 3 m on either side of the route
- have no unprotected openings from adjacent structures, within 2 m
226. It is important that doors necessary for escape be easily openable while the premises are occupied. Where a door across an escape route has to be secured against entry, it should be fitted with a fastening which is readily operated without a key, from the side approached by people making their escape. Where a door is operated by a code, combination, card, biometric data or similar means, it should be capable of being manually overridden from the side approached by people making their escape.
227. Push pad devices (to BS EN 179) are suitable securing devices for outward opening final exit doors where occupants can be expected to be familiar with the devices. In other cases, panic exit devices operated by a horizontal bar (to BS EN 1125), are suitable.
Electrically powered locks
228. Electrically powered locks can be operated by electromagnetic or electromechanical means.
229. Electrically powered locks should not be installed on any door which provides the only route of escape for persons, or which serves a room or storey with more than 60 persons, or a door on a fire-fighting shaft.
230. Electrically powered locks should return to the unlocked position:
- on operation of the fire warning system
- on loss of power
- on actuation of a manual door release unit positioned at the door on the side approached by people making their escape (where the door provides escape in either direction, a unit should be installed on both sides)
231. BS 7273: Part 4 provides detailed guidance on the electrical control arrangements for the fail-safe release of powered locks.
Automatic Opening Doors
232. An internal door may be linked to a motion sensor or other device so that the door opens automatically to facilitate movement of residents. Some devices can be triggered by smoke movement which may cause a door to open precisely at the time when it should be closed as a barrier to fire and smoke. These doors should be linked to the fire warning system so that the automatic opening function is disabled if the fire warning system is triggered (but still permitting the door to be manually opened). If the door is a fire door, the opening mechanism should not reduce the fire resistance of the door. When the automatic opening function is disabled following activation of the fire warning system, the fire door’s normal self-closing function should continue to operate.
233. Automatic opening doors should not be placed across exits unless they are designed in accordance with BS 7036 and are either:
- arranged to fail safely to outward opening from any position of opening; or
- are provided with a monitored fail-safe system for opening the door from any position in the event of mains supply failure and also in the event of failure of the opening sensing device; and open automatically from any position in the event of operation of the fire alarm in the fire alarm zone within which the door is situated.
Powered sliding doors
234. Powered sliding doors often open in response to a motion sensor. Such a door across an escape route, should be fail-safe and should open:
- on operation of the fire warning system
- on loss of power
- on activation of a manual door release unit positioned at the door on the side approached by people making their escape (where the door provides escape in either direction, a unit should be installed on both sides).
235. BS 7273: Part 4 contains detailed guidance on the electrical control arrangements for fail-safe operation of powered sliding doors.
236. Escape routes should be provided with lighting to allow persons to safely use these routes in the event of a fire occurring or in the event of failure of the normal lighting power supply.
Escape route lighting
237. Premises should be provided with lighting in the escape routes to the extent necessary to ensure that in the event of an outbreak of fire, illumination is provided to assist in escape and to aid staff in implementing the emergency fire action plan.
238. If there are escape routes that are not permanently illuminated, such as external stairs, then a marked switch or some other means of switching on the lighting, such as a motion sensor, should be provided.
Emergency escape lighting
239. Emergency lighting is lighting designed to operate or remain in operation automatically in the event of a local or general power failure. The size and type of the premises and the risk to the occupants will determine whether there is a need for emergency escape lighting.
240. Emergency lighting can be stand-alone dedicated units or incorporated into normal light fittings. Power supplies can be rechargeable batteries integral to each unit or a central battery bank. Single ‘stand-alone’ emergency lighting units may be sufficient in some premises and these can sometimes be combined with exit or directional exit signs, though the level of general illumination should not be significantly reduced by the sign.
241. Emergency lighting is described as ‘maintained’ if it is permanently illuminated, and ‘non-maintained’ when it only operates if the normal lighting fails.
242. A system of automatic emergency lighting is likely to be needed in large premises, particularly in those with extensive occupied basements, or where there are significant numbers of people. If some escape routes are internal and without windows, then some form of emergency lighting may be required. Emergency lighting may be necessary in a room with more than 60 occupants and escape routes serving such a room and escape routes in public access buildings which have two storey exits.
243. An emergency lighting system provided for escape purposes may be used to illuminate the following:
- internal and external escape routes, exit doors and escape route signs
- intersections of corridors
- staircases so that each flight receives adequate light
- changes in floor level
- fire-fighting equipment
- fire alarm call points
- equipment that needs to be shut down in an emergency
244. New emergency lighting systems should comply with BS 5266: Part 1.
Signs and Notices
245. In small simple premises where the locations of escape routes and fire-fighting equipment are readily apparent then fire signs may not be necessary.
246. Escape route signs are used to indicate escape routes not in normal use and are only necessary where there might otherwise be confusion regarding the route to follow in the event of fire. The following criteria apply to escape route signs:
- they should provide enough information to enable people to identify escape routes
- where the location of an exit is not obvious, signs with directional arrows may be provided along the route
- escape route and exit signs should not be fixed to doors as they may not be visible if the door is open
- signs mounted above doors should be at a height of between 2 m and 2.5 m above the floor
- signs on walls should be mounted between 1.7 m and 2 m above the floor
247. The legibility of an escape sign is determined by the size of the sign, the level of illumination and the distance over which it is viewed. Signs should be in pictogram form. The pictogram can be supplemented by text and/or directional arrows if necessary to make the sign easily understood. Guidance on the use of escape route signs is available in BS 5499: Part 10.
248. Signs to indicate the location of non-automatic fire safety equipment may be necessary if there is any doubt about its location, such as fire extinguishers that are kept in cabinets or in recesses. Other signs may also be necessary such as:
- ‘Fire door keep shut’ or ‘Fire door keep locked shut’ on fire doors
- ‘Automatic fire door – keep clear’
- how to operate the securing devices on doors
- location of sprinkler stop valve
249. New safety signs should comply with BS EN ISO 7010.
250. Notices are used to provide instructions on how to use any fire safety equipment and the actions to take in the event of fire. Notices containing details of the emergency fire action plan specific to the premises should be permanently displayed in appropriate positions throughout the building. A distinction may be required between notices that are designed for visitors, guests or residents as opposed to those for staff. Notices giving full instruction for staff should also be displayed on staff notice boards. Notices for guests and residents should be provided in each bedroom and in common areas, where appropriate, and should include a simple layout plan of the floor level.
251. If premises regularly accommodate people whose first language is not English there may be a need to consider providing instruction in appropriate languages.
Email: Linda White
Phone: 0300 244 4000 – Central Enquiry Unit
The Scottish Government
St Andrew's House