Items where Subject is "B1: Means of warning and escape"
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Means of warning and escape
B1.The building shall be designed and constructed so that there are appropriate provisions for the early warning of fire, and appropriate means of escape in case of fire from the building to a place of safety outside the building capable of being safely and effectively used at all material times.
Requirement B1 does not apply to any prison provided under section 33 of the Prison Act 1952
(a) (power to provide prisons, etc.).
(a) 1952 c. 52; section 33 was amended by section 100 of the Criminal Justice and Public Order Act 1994 (c. 33) and by S.I. 1963/597.
In the Secretary of State’s view, requirement B1 is met by achieving all of the following.
a. There are sufficient means for giving early warning of fire to people in the building.
b. All people can escape to a place of safety without external assistance.
c. Escape routes are suitably located, sufficient in number and of adequate capacity.
d. Where necessary, escape routes are sufficiently protected from the effects of fire and smoke.
e. Escape routes are adequately lit and exits are suitably signed.
f. There are appropriate provisions to limit the ingress of smoke to the escape routes, or to
restrict the spread of fire and remove smoke.
g. For buildings containing flats, there are appropriate provisions to support a stay put evacuation
strategy.
The extent to which any of these measures are necessary is dependent on the use of the building,
its size and its height.
Building work and material changes of use subject to requirement B1 include both new and existing
buildings.
All dwellings should have a fire detection and alarm system, minimum Grade D2 Category LD3
standard, in accordance with the relevant recommendations of BS 5839-6.
A higher standard of protection should be considered where occupants of a proposed dwelling
would be at special risk from fire. Further advice on this is also given in BS 5839-6.
Each flat in a block should have alarms as set out in paragraphs 1.1 to 1.4. With effective compartmentation, a communal fire alarm system is not normally needed. In some buildings, detectors in common parts of the building may need to operate smoke control or other fire protection systems but do not usually sound an audible warning.
Smoke alarms should be provided in the circulation spaces of the dwelling in accordance with paragraphs 1.1 to 1.4.
See paras 2.1 to 2.6
Single storey dwellinghouse(see paragraph 2.1)
Dwellinghouse with one storey more than 4.5m above ground level(see paragraph 2.5)
Dwellinghouse with two or more storeys more than 4.5m above ground level(see paragraph 2.6)
Windows or external doors providing emergency escape should comply with all of the following.
a. Windows should have an unobstructed openable area that complies with all of the following.
i. A minimum area of 0.33m2.
ii. A minimum height of 450mm and a minimum width of 450mm (the route through the window may be at an angle rather than straight through).
iii. The bottom of the openable area is a maximum of 1100mm above the floor.
b. People escaping should be able to reach a place free from danger from fire. Courtyards or inaccessible back gardens should comply with Diagram 2.5.
c. Locks (with or without removable keys) and opening stays (with child-resistant release catches) may be fitted to escape windows.
d. Windows should be capable of remaining open without being held.
An inner room is permitted when it is one of the following.
a. A kitchen.
b. A laundry or utility room.
c. A dressing room.
d. A bathroom, WC or shower room.
e. Any room on a storey that is a maximum of 4.5m above ground level which is provided with an emergency escape window as described in paragraph 2.10.
f. A gallery that complies with paragraph 2.15.
A room accessed only via an inner room (an inner inner room) is acceptable when all of the following apply.
a. It complies with paragraph 2.11.
b. The access rooms each have a smoke alarm (see Section 1).
c. None of the access rooms is a kitchen.
Where a flat roof forms part of a means of escape, it should comply with all of the following.
a. It should be part of the same building from which escape is being made.
b. The route across the roof should lead to a storey exit or external escape route.
c. The part of the roof (including its supporting structure) forming the escape route, and any opening within 3m of the escape route, should be of fire resisting construction (minimum REI 30).
A balcony or flat roof intended to form part of an escape route should be provided with guarding etc. in accordance with Approved Document K.
A gallery should comply with one of the following.
a. It should be provided with an alternative exit.
b. It should be provided with an emergency escape window, as described in paragraph 2.10, where the gallery floor is a maximum of 4.5m above ground level.
c. It should meet all the conditions shown in Diagram 2.6.
Basement storeys containing habitable rooms should have one of the following.
a. An emergency escape window or external door providing escape from the basement (paragraph 2.10).
b. A protected stairway (paragraph 2.5a) leading from the basement to a final exit.
Any external escape stair should meet all of the following conditions (Diagram 2.7).
a. Doors to the stair should be fire resisting (minimum E 30), except for a single exit door from the building to the top landing of a downward-leading external stair.
b. Fire resisting construction (minimum RE 30) is required for the building envelope within the following zones, measured from the flights and landings of the external stair.
i. 1800mm horizontally.
ii. 9m vertically below.
iii. 1100mm above the top landing of the stair (except where the stair leads from basement to ground level).
c. Fire resisting construction (minimum RE 30) should be provided for any part of the building (including doors) within 1800mm of the escape route from the foot of the stair to a place of safety. This does not apply if there are alternative escape routes from the foot of the external escape stair.
d. Stairs more than 6m in height should be protected from adverse weather. Protection should prevent the build-up of snow or ice but does not require full enclosure.
e. Glazing in areas of fire resisting construction should be fixed shut and fire resisting (in terms of integrity, but not insulation) (minimum E 30).
Work should comply with Parts K and L of Schedule 1 to the Building Regulations. When complete, the building should comply with other applicable parts of Schedule 1 to at least the same level as before.
Where an existing window would be an escape window in a new dwellinghouse, and is big enough to be used for escape purposes, then the replacement should comply with one of the following.
a. The replacement window should be sized to provide at least the same potential for escape.
b. If the existing window was larger than required for escape purposes, the opening can be reduced to the minimum described in paragraph 2.10.
See Diagram 2.1b. Where served by only one stair, all habitable rooms (excluding kitchens) should have either of the following.
a. An emergency escape window or external door, as described in paragraph 2.10.
b. Direct access to a protected stairway, as described in paragraph 2.5a.
See para 2.5
Fire resisting construction minimum REI 30
Fd Fire doorset minimum E 20
If windows are replaced, it may be necessary to provide cavity barriers around the opening in accordance with Section 5.
Where a new storey is added through conversion to create a storey above 4.5m, both of the following should apply.
a. The full extent of the escape route should be addressed.
b. Fire resisting doors (minimum E 20) and partitions (minimum REI 30) should be provided, including upgrading the existing doors where necessary.
NOTE: Where the layout is open plan, new partitions should be provided to enclose the escape route (Diagram 2.2).
Where it is undesirable to replace existing doors because of historical or architectural merit, the possibility of retaining, and where necessary upgrading, them should be investigated.
An alternative approach to that described in paragraph 2.21 would be to comply with all of the following.
a. Provide sprinkler protection to the open-plan areas.
b. Provide a fire resisting partition (minimum REI 30) and door (minimum E 20) to separate the ground storey from the upper storeys. The door should allow occupants of the loft room access to a first storey escape window.
c. Separate cooking facilities from the open-plan area with fire resisting construction (minimum REI 30).
Two rooms may be served by a single window. A door between the rooms should provide access to the window without passing through the stair enclosure. Both rooms should have their own access to the internal stair.
See para 2.5
Alternative cavity barrier arrangements in roof space over protected stairway in a house with a storey more than 4.5m above ground level
Dwellinghouses with one internal stair should comply with paragraphs 2.5 and 2.6. In dwellinghouses with more than one stair, the stairs should provide effective alternative means of escape. The stairs should be physically separated by either of the following.
a. Fire resisting construction (minimum REI 30).
b. More than one room.
See para 2.6
Example of alternative exit in para 2.6(a) (see definition in Appendix A)
See Diagram 2.1c. The dwellinghouse should have either of the following. Cavity barriers or a fire resisting ceiling (minimum EI 30) should be provided above a protected stairway enclosure (Diagram 2.3). b. Alternative escape route – a top storey separated from lower storeys by fire resisting construction (minimum REI 30) and with an alternative escape route leading to its own final exit.
a. Protected stairway – a stair separated by fire resisting construction (minimum REI 30) at all storeys, that complies with one of the following.
i. Extends to a final exit (Diagram 2.2a).
ii. Gives access to a minimum of two ground level final exits that are separated from each other by fire resisting construction (minimum REI 30) and fire doorsets (minimum E 20) (Diagram 2.2b).
Where escape from a dwellinghouse is to an enclosed space with exit only possible through other buildings (e.g. a courtyard or back garden), the length of the space should exceed whichever is the greater of the following.
a. The height of the dwellinghouse above ground level (x).
b. Where a rear extension is provided, the height of the extension (y).
See para 2.10
See Diagram 2.1d. In addition to meeting the provisions in paragraph 2.5, the dwellinghouse should comply with either of the following.
a. Provide an alternative escape route from each storey more than 7.5m above ground level. At the first storey above 7.5m, the protected stairway should be separated from the lower storeys by fire resisting construction (minimum REI 30) if the alternative escape route is accessed via either of the following.
i. The protected stairway to an upper storey.
ii. A landing within the protected stairway enclosure to an alternative escape route on the same storey. The protected stairway at or about 7.5m above ground level should be separated from the lower storeys or levels by fire resisting construction (see Diagram 2.4).
b. Provide a sprinkler system throughout, designed and installed in accordance with BS 9251.
NOTES:
1. This diagram does not apply where the gallery is provided with one of the following:
i. An alternative escape route
ii. An emergency escape window (where the gallery floor is not more than 4.5m above ground level).
2. Any cooking facilities within a room containing a gallery should comply with one of the following conditions:
i. Be enclosed with fire resisting construction
ii. Be remote from the stair to the gallery and positioned such that they do not prejudice escape from the gallery.
See para 2.15
A passenger lift serving any storey more than 4.5m above ground level should be in either of the following.
a. The enclosure to the protected stairway, as described in paragraph 2.5.
b. A fire resisting lift shaft (minimum REI 30).
Fire resisting window(minimum RE30)
No fire resistance required for door
1100mm zone above top landing
6m max. height without weather protection
1800mm zone of fire resisting construction at side of stairway
Fire doorset(minimum E30)
See para 2.17
Air circulation systems which circulate air within an individual dwellinghouse with a floor more than
4.5m above ground level should meet the guidance given in paragraph 2.9.
All of the following precautions should be taken to avoid the spread of smoke and fire to the protected stairway.
a. Transfer grilles should not be fitted in any wall, door, floor or ceiling of the stair enclosure.
b. Any duct passing through the stair enclosure should be rigid steel. Joints between the ductwork and stair enclosure should be fire-stopped.
c. Ventilation ducts supplying or extracting air directly to or from a protected stairway should not serve other areas as well.
d. Any system of mechanical ventilation which recirculates air and which serves both the stair and other areas should be designed to shut down on the detection of smoke within the system.
e. For ducted warm air heating systems, a room thermostat should be sited in the living room. It should be mounted at a height between 1370mm and 1830mm above the floor. The maximum setting should be 27°C.
NOTE: Ventilation ducts passing through compartment walls should comply with the guidance in Section 9.
Separate guidance applies to means of escape within the flat and within the common parts of the building that lead to a place of safety. Flats at ground level are treated similarly to dwellinghouses. With increasing height, more complex provisions are needed.
NOTES:
1. If travel distance is measured to a stair lobby, the lobby must not provide direct access to any storage room, flat or other space containing a fire hazard.
2. In the case of a small single stair building in accordance with Diagram 3.9, this is reduced to 4.5m.
3. Does not apply if all flats on a storey have independent alternative means of escape.
4. Sheltered housing may require reduced maximum travel distances.
NOTES:
1. This diagram does not apply where the gallery is provided with one of the following:
i. An alternative escape route
ii. An emergency escape window (where the gallery floor is not more than 4.5m above ground level).
2. Any cooking facilities within a room containing a gallery should comply with one of the following conditions:
i. Be enclosed with fire resisting construction
ii. Be remote from the stair to the gallery and positioned such that they do not prejudice escape from the gallery.
See para 3.13
Where a flat roof forms part of a means of escape, it should comply with all of the following.
a. It should be part of the same building from which escape is being made.
b. The route across the roof should lead to a storey exit or external escape route.
c. The part of the roof (including its supporting structure) forming the escape route, and any opening within 3m of the escape route, should be of fire resisting construction (minimum REI 30).
Configurations of stairs and external wall
Fire resisting construction
Fire resisting construction of adjacent building enclosure of protected stairway
Non-fire resisting construction
See para 3.63
A balcony or flat roof intended to form part of an escape route should be provided with guarding etc. in accordance with Approved Document K.
No fire resistance required for door
1100mm zone above top landing
1100mm zone above top landing
6m maximum height of stair
Fire resisting window (minimum RE30)
1800mm zone of fire resisting construction at side of stair
Fire doorset (minimum E30)
Ground level or a roof or podium served by an independent stairway
6m maximum height of stair without weather protection
9m zone of fire resisting construction below stair
Ground level or a roof or podium served by an independent stairway
See para 3.68
For flats more than 4.5m above ground level, a balcony outside an alternative exit should be a common balcony meeting the conditions described in paragraph 3.22.
A gallery should comply with one of the following.
a. It should be provided with an alternative exit.
b. It should be provided with an emergency escape window, as described in paragraph 3.6, where the gallery floor is a maximum of 4.5m above ground level.
c. It should meet the conditions shown in Diagram 3.1.
All habitable rooms (excluding kitchens) should have either of the following.
a. An opening directly onto a hall leading to a final exit.
b. An emergency escape window or door, as described in paragraph 3.6.
All habitable rooms (excluding kitchens) should have either of the following.
a. An emergency escape window or external door, as described in paragraph 3.6.
b. In multi-storey flats, direct access to a protected internal stairway (minimum REI 30) leading to an exit from the flat.
Two rooms may be served by a single escape window. A door between rooms should provide access to the escape window without passing through the stair enclosure. Both rooms should have their own access to the internal stair.
The provisions in this section make the following assumptions.
a. Any fire is likely to be in a flat.
b. There is no reliance on external rescue.
c. Simultaneous evacuation of all flats is unlikely to be necessary due to compartmentation.
d. Fires in common parts of the building should not spread beyond the fabric in the immediate vicinity. In some cases, however, communal facilities exist that require additional measures to be taken.
See para 3.18
NOTE: Bathrooms do not need to have fire doorsets provided that the bathroom is separated by fire resisting construction from the adjacent rooms.
A 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 Section 2, depending on the height of the top storey above ground level.
Any alternative exit from a flat should comply with all of the following.
a. It should be remote from the main entrance door to the flat.
b. It should lead to a final exit, via a common stair if necessary, through one of the following.
i. A door to an access corridor, access lobby or common balcony.
ii. An internal private stair leading to an access corridor, access lobby or common balcony at another level.
iii. A door to a common stair.
iv. A door to an external stair.
v. A door to an escape route over a flat roof.
Any access route leading to a final exit or common stair should comply with the provisions for means of escape in the common parts of a flat (see paragraph 3.25).
For systems circulating air only within an individual flat, take all of the following precautions.
a. Transfer grilles should not be fitted in any wall, door, floor or ceiling of the enclosure.
b. Any duct passing through the enclosure should be rigid steel. Joints between the ductwork and enclosure should be fire-stopped.
c. Ventilation ducts serving the enclosure should not serve any other areas.
d. Any system of mechanical ventilation which recirculates air and which serves both the stair and other areas should be designed to shut down on the detection of smoke within the system.
e. For ducted warm air heating systems, a room thermostat should be sited in the living room. It should be mounted at a height between 1370mm and 1830mm above the floor. The maximum setting should be 27°C.
NOTE: Ventilation ducts passing through compartment walls should comply with the guidance in Section 9.
For flats serving as a workplace for both occupants and people who do not live on the premises, provide both of the following.
a. A maximum travel distance of 18m between any part of the working area and either of the following.
i. The flat entrance door.
ii. An alternative means of escape that is not a window.
If the travel distance is over 18m, the assumptions in paragraph 3.2 may not be valid. The design should be considered on a case-by-case basis.
b. Escape lighting to windowless accommodation in accordance with BS 5266-1.
A person escaping through the common area, if confronted by the effects of a fire in another flat, should be able to turn away from it and make a safe escape via an alternative route.
From the flat entrance door, a single escape route is acceptable in either of the following cases.
a. The flat is on a storey served by a single common stair and both of the following apply.
i. Every flat is separated from the common stair by a protected lobby or common protected corridor (see Diagram 3.7).
ii. The maximum travel distance in Table 3.1, for escape in one direction only, is not exceeded.
b. The flat is in a dead end of a common corridor served by two (or more) common stairs and the maximum travel distance given in Table 3.1, for escape in one direction only, is not exceeded (Diagram 3.8).
For some low rise buildings, the provisions in paragraphs 3.26 and 3.27 may be modified and the use of a single stair, protected in accordance with Diagram 3.9, may be permitted where all of the following apply.
a. The top storey of the building is a maximum of 11m above ground level.
b. No more than three storeys are above the ground storey.
c. The stair does not connect to a covered car park, unless the car park is open sided (as defined in Section 11 of Approved Document B Volume 2).
d. The stair does not serve offices, stores or other ancillary accommodation. If it does, they should be separated from the stair by a protected lobby or protected corridor (minimum REI 30) with a minimum 0.4m2 of permanent ventilation, or be protected from the ingress of smoke by a mechanical smoke control system.
NOTE: For refuse chutes and storage see paragraphs 3.55 to 3.58.
e. Either of the following is provided for the fire and rescue service.
i. A high-level openable vent with a free area of at least 1m2 at each storey.
ii. A single openable vent with a free area of at least 1m2 at the head of the stair, operable remotely at the fire and rescue service access level.
Paragraph 3.27 may be modified using the guidance in clause 7.3 of BS 9991.
Provisions are recommended to support a stay put evacuation strategy for blocks of flats. It is based on the principle that a fire is contained in the flat of origin and common escape routes are maintained relatively free from smoke and heat. It allows occupants, some of whom may require assistance to escape in the event of a fire, in other flats that are not affected to remain.
Sufficient protection to common means of escape is necessary to allow occupants to escape should they choose to do so or are instructed/aided to by the fire service. A higher standard of protection is therefore needed to ensure common escape routes remain available for a longer period than is provided in other buildings.
See para 3.18
Flat entrance
Kitchen area
Bath
Where a storey or part of a building has multiple escape routes available, one may be over a flat roof that complies with all of the following.
a. It should be part of the same building from which escape is being made.
b. The route across the roof should lead to a storey exit or external escape route.
c. The part of the roof (including its supporting structure) forming the escape route, and any opening within 3m of the escape route, should be of fire resisting construction (minimum REI 30).
d. The route should be clearly defined and guarded by walls and/or protective barriers to protect against falling.
Where a storey or part of a building has multiple escape routes available, one may be over a flat roof that complies with all of the following.
d. The route should be clearly defined and guarded by walls and/or protective barriers to protect against falling.
The following paragraphs deal with means of escape from the entrance doors of flats to a final exit.
Escape route travel distances should comply with Table 3.1.
An escape route should not pass through one stair enclosure to reach another. It may pass through a protected lobby (minimum REI 30) of one stair to reach another.
Common corridors should be protected corridors. The wall between each flat and the corridor should be a compartment wall (minimum REI 30 where the top storey is up to 5m above ground level, otherwise REI 60).
Divide a common corridor connecting two or more storey exits with a fire doorset fitted with a self-closing device (minimum E 30 Sa). See Diagram 3.8. Associated screens should be fire resisting. Site doors so that smoke does not affect access to more than one stair.
A fire doorset (minimum E 30 Sa) fitted with a self-closing device (and fire resisting screen, where required) should separate the dead-end portion of a common corridor from the rest of the corridor (Diagrams 3.7a, 3.8b and 3.8c).
Ancillary accommodation should not be located in, or entered from, a protected lobby or protected corridor forming the only common escape route on that storey.
Escape routes should have a minimum clear headroom of 2m. The only projections allowed below this height are door frames.
Escape route floor finishes should minimise their slipperiness when wet. Finishes include the treads of steps and surfaces of ramps and landings.
Paragraphs 3.6 to 3.23 deal with the means of escape within each flat. Paragraphs 3.25 to 3.89 deal with the means of escape in common areas of the building (including mixed use buildings in paragraphs 3.76 and 3.77). Guidance for live/work units is given in paragraph 3.24.
See para 3.19
NOTE: The bedrooms are not classified as inner rooms because escape is possible in two directions.
Fire doorset
Fire resisting construction (minimum REI 30) between living and bedroom accommodation
Alternative exit
A ramp forming part of an escape route should meet the provisions in Approved Document M. Any sloping floor or tier should have a pitch of not more than 35 degrees to the horizontal.
In addition, escape lighting should be provided to all of the following.
a. Toilet accommodation with a minimum floor area of 8m2.
b. Electricity and generator rooms.
c. Switch room/battery room for emergency lighting system.
d. Emergency control rooms.
Escape stair lighting should be on a separate circuit from the electricity supply to any other part of the escape route.
Escape lighting should conform to BS 5266-1.
Every doorway or other exit providing access to a means of escape, other than exits in ordinary use (e.g. main entrances), should be distinctively and conspicuously marked by an exit sign in accordance with BS ISO 3864-1 and BS 5499-4. For this reason, blocks of flats with a single stair in regular use would not usually require any fire exit signage.
Advice on fire safety signs, including emergency escape signs, is given in the HSE publication Safety Signs and Signals: Guidance on Regulations.
Some buildings may require additional signs to comply with other legislation.
To limit potential damage to cables in protected circuits, all of the following should apply.
a. Cables should be sufficiently robust.
b. Cable routes should be carefully selected and/or physically protected in areas where cables may be exposed to damage.
c. Methods of cable support should be class A1 rated and offer at least the same integrity as the cable. They should maintain circuit integrity and hold cables in place when exposed to fire.
A protected circuit to operate equipment during a fire should achieve all of the following.
a. Cables should achieve PH 30 classification when tested in accordance with BS EN 50200 (incorporating Annex E) or an equivalent standard.
b. It should only pass through parts of the building in which the fire risk is negligible.
c. It should be separate from any circuit provided for another purpose.
Guidance on cables for large and complex buildings is given in BS 5839-1, BS 5266-1 and BS 8519.
Despite the provisions described, it is probable that some smoke will get into the common corridor or lobby from a fire in a flat.
There should therefore be some means of ventilating the common corridors/lobbies to control smoke and so protect the common stairs. This means of ventilation offers additional protection to that provided by the fire doors to the stair, as well as some protection to the corridors/lobbies.
Ventilation can be natural (paragraphs 3.50 to 3.53) or mechanical (paragraph 3.54).
In mixed use buildings, separate means of escape should be provided from any storeys or parts of storeys used for the ‘residential’ or ‘assembly and recreation’ purpose groups (purpose groups 1, 2 and 5), other than in the case of certain small buildings or buildings in which the residential accommodation is ancillary (see paragraphs 3.76 and 3.77)
See para 3.21
NOTE: This only applies where at least one storey is more than 4.5m above ground level.
Alternative exit
Bathroom
ENTRANCE LEVEL
LEVEL(S) ABOVE OR BELOW ENTRANCE LEVEL
Except in buildings that comply with Diagram 3.9, the corridor or lobby next to each stair should have a smoke vent. The location of the vent should comply with both of the following.
a. Be as high as practicable.
b. Be positioned so the top edge is at least as high as the top of the door to the stair.
A vent to the outside with a minimum free area of 1m2 should be provided from the top storey of the stair.
In single stair buildings, smoke vents on the storey where the fire is initiated, and the vent at the head of the stair, should be activated by smoke detectors in the common parts.
In buildings with more than one stair, smoke vents may be activated manually. The control system should open the vent at the head of the stair before, or at the same time as, the vent on the storey where the fire is located. Smoke detection is not required for ventilation purposes in this instance.
Guidance on the design of smoke control systems that use pressure differentials is available in BS EN 12101-6.
Refuse storage chambers, refuse chutes and refuse hoppers should be sited and constructed in accordance with BS 5906.
Refuse chutes and rooms for storing refuse should meet both of the following conditions.
a. Be separated from other parts of the building by fire resisting construction (minimum REI 30 in buildings with a top storey up to 5m above ground level; otherwise REI 60).
b. Not be situated within a protected stairway or protected lobby.
The approach to rooms containing refuse chutes or for storing refuse should comply with one of the following conditions.
a. Be directly from the open air.
b. Be through a protected lobby with a minimum of 0.2m2 of permanent ventilation.
Access openings to refuse storage chambers should not be sited in the following areas.
a. Next to escape routes or final exits.
b. Near the windows of flats.
A building should provide access to more than one common stair if it does not meet the criteria for a single common stair (see paragraph 3.26 and 3.27).
Windows or external doors providing emergency escape should comply with all of the following.
a. Windows should have an unobstructed openable area that complies with all of the following.
i. A minimum area of 0.33m2.
ii. A minimum height of 450mm and a minimum width of 450mm (the route through the window may be at an angle rather than straight through).
iii. The bottom of the openable area is a maximum of 1100mm above the floor.
b. People escaping should be able to reach a place free from danger from fire.
c. Locks (with or without removable keys) and opening stays (with child-resistant release catches) may be fitted to escape windows.
d. Windows should be capable of remaining open without being held.
See para 3.21
NOTE: This only applies where at least one storey is more than 4.5m above ground level.
Fire doorset
Fire resisting stair enclosure(minimum REI 30)
Alternative exit
A stair of acceptable width for everyday use will be sufficient for escape purposes. If it is also a firefighting stair, it should be at least 1100mm wide. The width is the clear width between the walls or balustrades. Any handrails and strings intruding into that width by a maximum of 100mm on each side may be ignored.
Section 7 provides guidance on avoiding the spread of fire between storeys. For a stair that is also a firefighting stair, guidance in Section 15 should be followed.
With some configurations of external wall, a fire in one part of a building could subject the external wall of a protected stairway to heat (for example, where the two are adjacent at an internal angle in the façade, as shown in Diagram 3.10).
If a protected stairway projects beyond, is recessed from or is in an internal angle of the adjoining external wall of the building, then the minimum distance between an unprotected area of the building enclosure and an unprotected area of the stair enclosure should be 1800mm.
Flats may be served by an external stair if the provisions in paragraphs 3.66 to 3.69 are followed.
An inner room is permitted when it is one of the following.
a. A kitchen.
b. A laundry or utility room.
c. A dressing room.
d. A bathroom, WC or shower room.
e. Any room on a storey that is a maximum of 4.5m above ground level which is provided with an emergency escape window as described in paragraph 3.6.
f. A gallery that complies with paragraph 3.13.
See paras 3.27 and 3.36
NOTES:
1. The arrangements shown also apply to the top storey.
2. See Diagram 3.9 for small single stair buildings.
3. All doors shown are fire doorsets.
4. Where travel distance is measured to a stair lobby, the lobby must not provide direct access to any storage room, flat or other space containing a potential fire hazard.
5. For further guidance on the fire rating of the fire doorsets from the corridor to the flat and/or stairway refer to Appendix C ,Table C1.
F Flat
Shaded areas indicate zones where ventilation should be provided in accordance with paragraphs 3.50 to 3.53(An external wall vent or smoke shaft located anywhere in the shaded area)
See paras 3.27 and 3.36
NOTES:
1. The arrangements shown also apply to the top storey.
2. See Diagram 3.9 for small single stair buildings.
3. All doors shown are fire doorsets.
4. Where travel distance is measured to a stair lobby, the lobby must not provide direct access to any storage room, flat or other space containing a potential fire hazard.
5. For further guidance on the fire rating of the fire doorsets from the corridor to the flat and/or stairway refer to Appendix C ,Table C1.
F Flat
Shaded areas indicate zones where ventilation should be provided in accordance with paragraphs 3.50 to 3.53(An external wall vent or smoke shaft located anywhere in the shaded area)
A room accessed only via an inner room (an inner inner room) is acceptable when all of the following apply.
a. It complies with paragraph 3.7.
b. The access rooms each have a smoke alarm (see Section 1).
c. None of the access rooms is a kitchen.
a. CORRIDOR ACCESS WITHOUT DEAD ENDS
b. CORRIDOR ACCESS WITH DEAD ENDS
The central door may be omitted if maximum travel distance is not more than 15m.
1. The arrangements shown also apply to the top storey.
2. For further guidance on the fire rating of the fire doorsets from the corridor to the flat and/or stairway refer to Appendix C ,Table C1.
Fire doorset provided in accordance with paragraphs 3.50 to 3.53(An external wall vent or smoke shaft located anywhere in the shaded area)
See paras 3.27 and 3.36
Basement storeys containing habitable rooms should have one of the following.
a. An emergency escape window or external door providing escape from the basement (see paragraph 3.6).
b. A protected stairway (minimum REI 30) leading from the basement to a final exit.
a. SMALL SINGLE STAIR BUILDING
*If smoke control is provided in the lobby, the travel distance can be increased to 7.5m maximum(see Diagram 3.7, example b).
b. SMALL SINGLE STAIR BUILDING WITH NO MORE THAN TWO FLATS PER STOREY
The door between stair and lobby should be free from security fastenings.
If the flats have protected entrance halls, the lobby between the common stair and flat entrance is not essential.
NOTES:
1. The arrangements shown also apply to the top storey.
2. If the travel distance across the lobby in diagram (a) exceeds 4.5m, Diagram 3.7 applies.
3. Where,in Diagram (b), the lobby between the common stair and the dwelling is omitted in smal lsingle stair buildings, an automatic opening vent with a free area of at least 1m2 is required at the top of the stair,which is operated automatically on detection of smoke at any storey in the stair.
4. For further guidance on the fire rating of the fire doorsets from the corridor to the flat and/or stairway refer to Appendix C, Table C1.
Fire resisting construction
Openable vent at high level for fire service use (1.0m2 minimum free area); see paragraph 3.28eSee para 3.28
Diagram 3.9
If a loadbearing wall is any of the following, guidance in other sections may also apply.
a. A compartment wall (including a wall common to two buildings): Section 7.
b. Enclosing a place of special fire hazard: Section 7.
c. Protecting a means of escape: Sections 2 and 3.
d. An external wall: Sections 10 and 11.
e. Enclosing a firefighting shaft: Section 15.
In a converted building with a maximum of three storeys, a minimum REI 30 fire resistance could be accepted for elements of structure if the means of escape conform to the provisions of Section 3.