2.1The means of escape from a flat with a floor not more than 4.5m above ground level is relatively simple to provide. Few provisions are specified in this document beyond ensuring that means are provided for giving early warning in the event of fire (see Section 1) and that suitable means are provided for emergency egress from these storeys.
With increasing height more complex provisions are needed because emergency egress through upper windows becomes increasingly hazardous.
2.1The guidance in this section deals with some common arrangements of flat design. Other, less common, arrangements (for example flats entered above or below accommodation level, or flats containing galleries) are acceptable. Guidance on these is given in clauses 9 and 10 of BS 5588-1:1990.
2.3The provisions for means of escape for flats are based on the assumption that:
- athe fire is generally in a flat;
- bthere is no reliance on external rescue (e.g. by a portable ladder);
- c measures in Section 8 (B3) provide a high degree of compartmentation and therefore a low probability of fire spread beyond the flat of origin, so that simultaneous evacuation of the building is unlikely to be necessary; and
- dalthough fires may occur in the common parts of the building, the materials and construction used there should prevent the fabric from being involved beyond the immediate vicinity (although in some cases communal facilities exist which require additional measures to be taken).
2.4There are two distinct components to planning means of escape from buildings containing flats; escape from within each flat and escape from each flat to the final exit from the building.
Paragraphs 2.5 to 2.18 deal with the means of escape within each unit, i.e. within the private domestic area. Paragraphs 2.19 to 2.48 deal with the means of escape in the common areas of the building. Guidance on mixed use buildings is given in paragraphs 2.50 to 2.51 and for live/ work units in 2.52.
2.5A room whose only escape route is through another room is at risk if a fire starts in that other room.
This situation may arise with open-plan layouts and galleries. Such an arrangement is only acceptable where the inner room is:
- a. a kitchen;
- ba laundry or utility room;
- ca dressing room;
- da bathroom, WC, or shower room;
- e any other room on a floor not more than 4.5m above ground level which complies with paragraph 2.6, 2.10, or 2.11b as appropriate; or
- fa gallery which complies with paragraph 2.8.
Notes: A room accessed only via an inner room (an inner-inner room) may be acceptable if it complies with the above, not more than one door separates the room from an interlinked smoke alarm and none of the access rooms are a kitchen.
2.6Because of the risk that a single stairway may be blocked by smoke from a fire in the basement or ground storey, if the basement storey contains any habitable room, either provide:
- aan external door or window suitable for egress from the basement (see paragraph 2.9); or
- ba protected stairway leading from the basement to a final exit.
Balconies and flat roofs
2.7Any balcony outside an alternative exit to a flat more than 4.5m above ground level should be a common balcony and meet the conditions in paragraph 2.17.
A flat roof forming part of a means of escape should comply with the following provisions:
- athe roof should be part of the same building from which escape is being made;
- bthe route across the roof should lead to a storey exit or external escape route; and
- cthe part of the roof forming the escape route and its supporting structure, together with any opening within 3m of the escape route, should provide 30 minutes fire resistance (see Appendix A Table A1).
Notes:Where a balcony or flat roof is provided for escape purposes, guarding may be needed, in which case it should meet the provisions in Approved Document K Protection from falling, collision and impact.
2.8A gallery should be provided with an alternative exit; or, where the gallery floor is not more than 4.5m above ground level, an emergency egress window which complies with paragraph 2.9. Where the gallery floor is not provided with an alternative exit or escape window, it should comply with the following:
- A.the gallery should overlook at least 50% of the room below (see Diagram1);
- B. the distance between the foot of the access stair to the gallery and the door to the room containing the gallery should not exceed 3m;
- C. the distance from the head of the access stair to any point on the gallery should not exceed 7.5m; and
- D. any cooking facilities within a room containing a gallery should either:
- i. be enclosed with fire-resisting construction; or
- ii. be remote from the stair to the gallery and positioned such that they do not prejudice the escape from the gallery.
**** Image Diagram 1 Gallery floors with no alternative exit ****
Emergency egress windows and external doors
2.9Any window provided for emergency egress purposes should comply with the following conditions:
- athe window should have an unobstructed openable area that is at least 0.33m2 and at least 450mm high and 450mm wide (the route through the window may be at an angle rather than straight through). The bottom of the openable area should be not more than 1100mm above the floor; and
- bthe window should enable the person escaping to reach a place free from danger from fire.
Notes: Approved Document K Protection from falling, collision and impact specifies a minimum guarding height of 800mm, except in the case of a window in a roof where the bottom of the opening may be 600mm above the floor.
Locks (with or without removable keys) and stays may be fitted to egress windows, subject to the stay being fitted with a release catch, which may be child resistant.
Windows should be designed such that they will remain in the open position without needing to be held by a person making their escape.
Provisions for escape from flats where the floor is not more than 4.5m above ground level
2.10The internal arrangement of flats (single or multi-storey) where no floor is more than 4.5m in height may either meet the provisions in paragraphs 2.11 to 2.12 or 2.13 to 2.18.
Notes:Where a flat is accesed via the common parts of a block of flats it may be necessary to provide a protected entrance hall to meet the provisions of Paragraph 2.21 and Diagram 9.
Provisions for escape from the ground storey
2.11Except for kitchens, all habitable rooms in the ground storey should either:
- aopen directly onto a hall leading to the entrance or other suitable exit; or
- bbe provided with a window (or door) which complies with paragraph 2.9.
Provisions for escape from upper floors not more than 4.5m above ground level
2.12Except for kitchens, all habitable rooms in the upper storey(s) should be provided with
- aa window (or external door) which complies with paragraph 2.9; or
- bin the case of a multi-storey flat, direct access to its own internal protected stairway leading to a final exit.
Notes:A single window can be accepted to serve two rooms provided both rooms have their own access to the stairs. A communicating door between the rooms must be provided so that it is possible to gain access to the window without passing through the stair enclosure.
Provisions for flats with a floor more than 4.5m above ground level
Internal planning of flats
2.13Three acceptable approaches (all of which should observe the restrictions concerning inner rooms given in paragraph 2.5) when planning a flat which has a floor at more than 4.5m above ground level are:
- ato provide a protected entrance hall which serves all habitable rooms, planned so that the travel distance from the entrance door to the door to any habitable room is 9m or less (see Diagram 2); or
- bto plan the flat so that the travel distance from the entrance door to any point in any of the habitable rooms does not exceed 9m and the cooking facilities are remote from the entrance door and do not prejudice the escape route from any point in the flat (see Diagram 3); or
- c to provide an alternative exit from the flat, complying with paragraph 2.14.
2.14Where any flat has an alternative exit and the habitable rooms do not have direct access to the entrance hall (see Diagram 4):
- athe bedrooms should be separated from the living accommodation by fire-resisting construction and fire door(s); and
- b the alternative exit should be located in the part of the flat containing the bedroom(s).
Internal planning of flats with more than one storey
2.15A multi-storey flat with an independent external entrance at ground level is similar to a dwellinghouse and means of escape should be planned on the basis of paragraphs 2.11 or 2.12 depending on the height of the top storey above ground level.
2.16Four acceptable approaches to planning a multi-storey flat, which does not have its own external entrance at ground level but has a floor at more than 4.5m above ground level, are:
- ato provide an alternative exit from each habitable room which is not on the entrance floor of the flat, (see Diagram 5); or
- bto provide one alternative exit from each floor (other than the entrance floor), with a protected landing entered directly from all the habitable rooms on that floor, (see Diagram 6); or
- cwhere the vertical distance between the floor of the entrance storey and the floors above and below it does not exceed 7.5m, to provide a protected stairway plus additional smoke alarms in all habitable rooms and a heat alarm in any kitchen; or
- d to provide a protected stairway plus a sprinkler system in accordance paragraph 0.16 (smoke alarms should also be provided in accordance with paragraph 1.9).
2.17To be effective, an alternative exit from a flat should satisfy the following conditions:
- abe remote from the main entrance door to the flat; and
- blead to a final exit or common stair by way of:
- ia door onto an access corridor, access lobby or common balcony; or
- iian internal private stair leading to an access corridor, access lobby or common balcony at another level; or
- iiia door into a common stair; or
- iva door onto an external stair; or
- va door onto an escape route over a flat roof.
Note: Any such access to a final exit or common stair should meet the appropriate provisions dealing with means of escape in the common parts of the building (see paragraph 2.19).
Air circulation systems in flats with a protected stairway or entrance hall
2.18Where ventilation ducts pass through compartment walls, then the guidance given paragraphs 5.46 to 5.53, 8.40 and 10.9 to 10.15 should be followed. Where an air circulation system circulates air only within an individual flat with an internal protected stairway or entrance hall the following precautions are needed to avoid the possibility of the system allowing smoke or fire to spread into the protected space.
- aTransfer grilles should not be fitted in any wall, door, floor or ceiling enclosing a protected stairway or entrance hall;
- bAny duct passing through through the enclosure to a protected stairway or entrance hall should of rigid steel construction and all joints between the ductwork and the enclosure should be fire-stopped,
- cVentilation ducts supplying or extracting air directly to or from a protected stairway or entrance hall, should not also serve other areas;
- dAny system of mechanical ventilation which recirculates air and which serves both the stairway or entrance hall and other areas should be designed to shut down on the detection of smoke within the system; and
- eA room thermostat for a ducted warm air heating system should be mounted in the living room at a height between 1370mm and 1830mm and its maximum setting should not exceed 27degC.
Means of escape in the common parts of flats
2.19The following paragraphs deal with means of escape from the entrance doors of flats to a final exit. They should be read in conjunction with the general provisions in Section 5.
Notes:Paragraphs 2.20 to 2.51 are not applicable where the top floor is not more than 4.5m above ground level and the flats are designed in accordance with paragraphs 2.11 and 2.12. However, attention is drawn to the provisions in paragraph 0.29 regarding sheltered housing, Section 5 regarding general provisions, Section 8 (B3) regarding the provision of compartment walls and protected shafts and Section 16 (B5) regarding the provision of access for the Fire and Rescue Service.
Number of escape routes
2.20Every flat should have access to alternative escape routes so that a person confronted by the effects of an outbreak of fire in another flat can turn away from it and make a safe escape.
However, a single escape route from the flat entrance door is acceptable if either:
the flat is situated in a storey served by a single common stair and:
every flat is separated from the common stair by a protected lobby or common corridor (see Diagram 7); and
the travel distance limitations in Table 1 (see paragraph 2.23), on escape in one direction only, are observed; or
alternatively the flat is situated in a dead end part of a common corridor served by two (or more) common stairs and the travel distance complies with the limitations in Table 1 on escape in one direction only (see Diagram 8).
Small single-stair buildings
2.21The provisions in paragraph 2.20 may be modified and a single stair, protected in accordance with Diagram 9, may be used provided that:
- athe top floor of the building is no more than 11m above ground level;
- bthere are no more than 3 storeys above the ground level storey;
- cthe stair does not connect to a covered car park;
- dthe stair does not serve ancillary accommodation unless the ancillary accommodation is separated from the stair by a protected lobby, or protected corridor, which has not less than 0.4m2 permanent ventilation or is protected from the ingress of smoke by a mechanical smoke control system; and
- ea high level openable vent, for fire and rescue service, use is provided at each floor level with a minimum free area of 1m2. Alternatively, a single openable vent may be provided at the head of the stair which can be remotely operated from fire and rescue service access level.
Flats with balcony or deck access
2.22The provisions of paragraph 2.20 may also be modified in the case of flats with balcony or deck approach. Guidance on these forms of development is set out in clause 13 of BS 5588-1:1990.
Planning of common escape routes
2.23Escape routes in the common areas should comply with the limitations on travel distance in Table 1. However, there may be circumstances where some increase on these maximum figures will be reasonable.
Escape routes should be planned so that people do not have to pass through one stairway enclosure to reach another. However, it is acceptable to pass through a protected lobby of one stairway in order to reach another.
Protection of common escape routes
2.24To reduce the risk of a fire in a flat affecting the means of escape from other flats and common parts of the building, the common corridors should be protected corridors.
The wall between each flat and the corridor should be a compartment wall (see Section 8).
Smoke control of common escape routes
2.25Despite the provisions described in this Approved Document, it is probable that some smoke will get into a common corridor or lobby from a fire in a flat, if only because the entrance door will be opened when the occupants escape.
There should therefore be some means of ventilating the common corridors/lobbies to control smoke and so protect the common stairs. This offers additional protection to that provided by the fire doors to the stair. (The ventilation also affords some protection to the corridors/lobbies.)
This can be achieved by either natural means in accordance with paragraph 2.26 or by means of mechanical ventilation as described in paragraph 2.27.
Smoke control of common escape routes by natural smoke ventilation
2.26In buildings, other than small ones complying with Diagram 9, the corridor or lobby adjoining the stair should be provided with a vent. The vent from the corridor/lobby should be located as high as practicable and such that the top edge is at least as high as the top of the door to the stair.
There should also be a vent, with a free area of at least 1.0m2, from the top storey of the stairway to the outside.
In single stair buildings the smoke vents on the fire floor and at the head of the stair should be actuated by means of smoke detectors in the common access space providing access to the flats. In buildings with more than one stair the smoke vents may be actuated manually (and accordingly smoke detection is not required for ventilation purposes). However, where manual actuation is used, the control system should be designed to ensure that the vent at the head of the stair will be opened either before, or at the same time, as the vent on the fire floor.
Vents should either:
- abe located on an external wall with minimum free area of 1.5m2 (see Appendix C); or
- bdischarge into a vertical smoke shaft (closed at the base) meeting the following criteria:
- iMinimum cross-sectional area 1.5m2 (minimum dimension 0.85m in any direction), opening at roof level at least 0.5m above any surrounding structures within a horizontal distance of 2.0m. The shaft should extend at least 2.5m above the ceiling of the highest storey served by the shaft;
- iiThe minimum free area of the vent from the corridor/lobby into the shaft and at the opening at the head of the shaft and at all internal locations within the shaft (e.g. safety grilles) should be at least 1.0m2 (see Appendix C);
- iiiThe smoke shaft should be constructed from non-combustible material and all vents should have a fire/smoke resistance performance at least that of an E30Sa fire door. The shaft should be vertical from base to head, with no more than 4m at an inclined angle (maximum 30deg); and
- ivOn detection of smoke in the common corridor/lobby, the vent(s) on the fire floor, the vent at the top of the smoke shaft and to the stairway should all open simultaneously. The vents from the corridors/lobbies on all other storeys should remain closed.
Smoke control of common escape routes by mechanical ventilation
2.27As an alternative to the natural ventilation provisions in paragraph 2.26, mechanical ventilation to the stair and/or corridor/lobby may be provided to protect the stair(s) from smoke. Guidance on the design of smoke control systems using pressure differentials is available in BS EN 12101-6:2005.
Sub-division of common escape routes
2.28A common corridor that connects two or more storey exits should be sub-divided by a self-closing fire door with, if necessary, any associated fire-resisting screen (see Diagram 8). The door(s) should be positioned so that smoke will not affect access to more than one stairway.
2.29A dead-end portion of a common corridor should be separated from the rest of the corridor by a self-closing fire door with, if necessary, any associated fire-resisting screen (see Diagram 7a and Diagram 8b and 8c).
Ancillary accommodation, etc.
2.302.30 Stores and other ancillary accommodation should not be located within, or entered from, any protected lobby or protected corridor forming part of the only common escape route from a flat on the same storey as that ancillary accommodation.
Reference should be made to paragraphs 5.54 to 5.57 for special provisions for refuse chutes and storage areas.
Escape routes over flat roofs
p>2.31If more than one escape route is available from a storey, or part of a building, one of those routes may be by way of a flat roof provided that it complies with the provisions in paragraph 5.35
Notes:Access to designs described in paragraph 2.48 may also be via a flat roof if the route over the roof complies with the provisions in paragraph 5.35.
Number of common stairs
2.32As explained in paragraph 2.19 and paragraph 2.20 a single common stair can be acceptable in some cases, but otherwise there should be access to more than one common stair for escape purposes.
Width of common stairs
2.33A stair of acceptable width for everyday use will be sufficient for escape purposes, but if it is also a firefighting stair, it should be at least 1100mm wide (see Appendix C for measurement of width).
Protection of common stairs
2.34Common stairs need to have a satisfactory standard of fire protection if they are to fulfil their role as areas of relative safety during a fire evacuation. The provisions in paragraphs 2.35 to 2.46 should be followed.
2.35Stairs provide a potential route for fire spread from floor to floor. In Section 7 under the requirement of B3 to inhibit internal fire spread, there is guidance on the enclosure of stairs to avoid this. A stair may also serve as a firefighting stair in accordance with the requirement B5, in which case account will have to be taken of the guidance in Section 17.
Enclosure of common stairs
2.36Every common stair should be situated within a fire-resisting enclosure (i.e. it should be a protected stairway), to reduce the risk of smoke and heat making use of the stair hazardous.
2.37The appropriate level of fire resistance is given in Appendix A, Tables A1 and A2.
Exits from protected stairways
2.38Every protected stairway should discharge:
- adirectly to a final exit; or
- bby way of a protected exit passageway to a final exit.
Notes:Any such protected exit passageway should have the same standard of fire resistance and lobby protection as the stairway it serves.
Separation of adjoining protected stairways
2.39Where two protected stairways (or exit passageways leading to different final exits) are adjacent, they should be separated by an imperforate enclosure.
Use of space within protected stairways
2.40A protected stairway needs to be relatively free of potential sources of fire. Consequently, it should not be used for anything else, except a lift well or electricity meter(s). There are other provisions for lifts in paragraphs 5.39 to 5.45. In single stair buildings, meters located within the stairway should be enclosed within a secure cupboard which is separated from the escape route with fire-resisting construction.
Fire resistance and openings in external walls of protected stairways
2.41The external enclosures to protected stairways should meet the provisions in paragraph 5.24.
Gas service and installation pipes in protected stairways
2.42Gas service and installation pipes or associated meters should not be incorporated within a protected stairway unless the gas installation is in accordance with the requirements for installation and connection set out in the Pipelines Safety Regulations 1996, SI 1996 No 825 and the Gas Safety (Installation and Use) Regulations 1998 SI 1998 No 2451 (see also paragraph 8.40).
2.43Because of their situation, basement stairways are more likely to be filled with smoke and heat than stairs in ground and upper storeys.
Special measures are therefore needed in order to prevent a basement fire endangering upper storeys. These are set out in the following two paragraphs.
2.44If an escape stair forms part of the only escape route from an upper storey of a building (or part of a building) which is not a small building (see paragraph 2.20), it should not be continued down to serve any basement storey. The basement should be served by a separate stair.
2.45If there is more than one escape stair from an upper storey of a building (or part of a building), only one of the stairs serving the upper storeys of the building (or part) need be terminated at ground level. Other stairs may connect with the basement storey(s) if there is a protected lobby or a protected corridor between the stair(s) and accommodation at each basement level.
Stairs serving accommodation ancillary to flats
2.46Except in small buildings described in paragraph 2.21, where a common stair forms part of the only escape route from a flat, it should not also serve any covered car park, boiler room, fuel storage space or other ancillary accommodation of similar fire risk.
2.47Any common stair which does not form part of the only escape route from a flat may also serve ancillary accommodation if it is separated from the ancillary accommodation by a protected lobby or a protected corridor.
If the stair serves an enclosed (non open-sided) car park, or place of special fire hazard, the lobby or corridor should have not less than 0.4m2 permanent ventilation or be protected from the ingress of smoke by a mechanical smoke control system.
External escape stairs
2.48If the building (or part of the building) is served by a single access stair, that stair may be external if it:
- aserves a floor not more than 6m above the ground level; and
- bmeets the provisions in paragraph 5.25.
2.49Where more than one escape route is available from a storey (or part of a building), some of the escape routes from that storey or part of the building may be by way of an external escape stair, provided that there is at least one internal escape stair from every part of each storey (excluding plant areas) and the external stair(s):
- aserves a floor not more than 6m above either the ground level or a roof or podium which is itself served by an independent protected stairway; and
- bmeets the provisions in paragraph 5.25.
Flats in mixed use buildings
2.50In buildings with not more than three storeys above the ground storey, stairs may serve both flats and other occupancies, provided that the stairs are separated from each occupancy by protected lobbies at all levels.
2.51In buildings with more than three storeys above the ground storey, stairs may serve both flats and other occupancies provided that:
- athe flat is ancillary to the main use of the building and is provided with an independent alternative escape route;
- bthe stair is separated from any other occupancies on the lower storeys by protected lobbies (at those storey levels);
Note: The stair enclosure should have at least the same standard of fire resistance as stipulated in Table A2 for the elements of structure of the building (and take account of any additional provisions in Section 17 if it is a firefighting stair).
- cany automatic fire detection and alarm system with which the main part of the building is fitted also covers the flat;
- dany security measures should not prevent escape at all material times.
Notes:Additional measures, including increased periods of fire resistance may be required between the flat and any storage area where fuels such as petrol and LPG are present.
2.52Where a flat is intended to serve as a workplace for its occupants and for persons who do not live on the premises, the following additional fire precautions will be necessary:
- aThe maximum travel distance to the flat entrance door or an alternative means of escape (not a window) from any part of the working area should not exceed 18m; and
- bAny windowless accommodation should have escape lighting which illuminates the route if the main supply fails. Standards for the installation of a system of escape lighting are given in BS 5266-1:2005.
Notes:Where the unit is so large that the travel distance in a. cannot be met then the assumptions set out in paragraph 2.3 may no longer be valid. In such circumstances the design of the building should be considered on a case by case basis.