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B
BCA technical guidance notes arefor the benefit of it's members and the construction industry, to provide information, promote good practice and encourage consistency of interpretation for the benefit of our clients. They are advisory in nature,and inall cases the responsibility for determining compliance with the Building Regulations remains with the building control body concerned. This guidance note is based upon information available at the time of issue and may be subject to change.The Approved Documents should be consulted for full details in any particular case.
Dimensions and performance for pipes and fittings made of ABS, MUPVC, PE or PP in nominal sizes of 1¼ by 32, 1½ by 40 and 2/50 for the conveyance of domestic effluent.
Sets out the framework for the engineering principles of fire safety in building design. Offers recommendations along with guidance for protecting people, property and the environment from fire and covers both new and existing buildings. Gives an overview for the design approach, and then covers the qualitative design review process, qualitative and quantitative analysis, acceptance criteria, quality assurance, reporting and presentation of results.
Details the procedure for reaction to fire classification covering all construction products, including those incorporated within building elements. Relates to three categories: construction products, floorings and linear pipe thermal insulation products.
For wallcovering products supplied in roll form, designed for hanging onto internal walls, partitions or ceilings, using an adhesive, whose primary purpose is decorative.
D
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.
Internal fire spread (linings)
B2.(1) To inhibit the spread of fire within the building, the internal linings shall —
(a) adequately resist the spread of flame over their surfaces; and
(b) have, if ignited, either a rate of heat release or a rate of fire growth, which is reasonable in the circumstances.
(2) In this paragraph “internal linings” means the materials or products used in lining any partition, wall, ceiling or other internal structure.
In the Secretary of State’s view, requirement B2 is met by achieving a restricted spread of flame
over internal linings. The building fabric should make a limited contribution to fire growth,
including a low rate of heat release.
It is particularly important in circulation spaces, where linings may offer the main means by which
fire spreads and where rapid spread is most likely to prevent occupants from escaping.
Requirement B2 does not include guidance on the following.
a. Generation of smoke and fumes.
b. The upper surfaces of floors and stairs.
c. Furniture and fittings.
B3.(1) The building shall be designed and constructed so that, in the event of fire, its stability will be maintained for a reasonable period
(2) A wall common to two or more buildings shall be designed and constructed so that it adequately resists the spread of fire between those buildings.
For the purposes of this sub-paragraph a house in a terrace and a semi-detached house are each to be treated as a separate building.
(3) Where reasonably necessary to inhibit the spread of fire within the building, measures shall be taken, to an extent appropriate to the size and intended use of the building, comprising either or both of the following—
(a) sub-division of the building with fire-resisting construction;
(b) installation of suitable automatic fire suppression systems.
(4) The building shall be designed and constructed so that the unseen spread of fire and smoke within concealed spaces in its structure and fabric is inhibited.
Requirement B3(3) does not apply to material alterations to any prison provided under section 33 of the Prison Act 1952.
In the Secretary of State’s view, requirement B3 is met by achieving all of the following.
a. For defined periods, loadbearing elements of structure withstand the effects of fire without
loss of stability.
b. Compartmentation of buildings by fire resisting construction elements.
c. Automatic fire suppression is provided where it is necessary.
d. Protection of openings in fire-separating elements to maintain continuity of the fire separation.
e. Inhibition of the unseen spread of fire and smoke in cavities, in order to reduce the risk of
structural failure and spread of fire and smoke, where they pose a threat to the safety of people
in and around the building.
The extent to which any of these measures are necessary is dependent on the use of the building
and, in some cases, its size, and on the location of the elements of construction.
External fire spread
B4.(1)The external walls of the building shall adequately resist the spread of fire over the walls and from one building to another, having regard to the height, use and position of the building.
(2)The roof of the building shall adequately resist the spread of fire over the roof and from one building to another, having regard to the use and position of the building.
Regulation 7 – Materials and workmanship
(1)Building work shall be carried out—
(a)with adequate and proper materials which—
(i)are appropriate for the circumstances in which they are used,
(ii)are adequately mixed or prepared, and
(iii)are applied, used or fixed so as adequately to perform the functions for which they are designed; and
(b)in a workmanlike manner.
(2)Subject to paragraph (3), building work shall be carried out so that materials which become part of an external wall, or specified attachment, of a relevant building are of European Classification A2-s1, d0 or A1, classified in accordance with BS EN 13501-1:2007+A1:2009 entitled “Fire classification of construction products and building elements. Classification using test data from reaction to fire tests” (ISBN 978 0 580 59861 6) published by the British Standards Institution on 30th March 2007 and amended in November 2009.
(3)Paragraph (2) does not apply to—
(a)cavity trays when used between two leaves of masonry;
(b)any part of a roof (other than any part of a roof which falls within paragraph (iv) of regulation 2(6))if that part is connected to an external wall;
(c)door frames and doors;
(d)electrical installations;
(e)insulation and water proofing materials used below ground level;
(f)intumescent and fire stopping materials where the inclusion of the materials is necessary to meet the requirements of Part B of Schedule 1;
(g)membranes;
(h)seals, gaskets, fixings, sealants and backer rods;
(i)thermal break materials where the inclusion of the materials is necessary to meet the thermal bridging requirements of Part L of Schedule 1; or
(j)window frames and glass.
(4)In this regulation—
(a)a “relevant building” means a building with a storey (not including roof-top plant areas or any storey consisting exclusively of plant rooms) at least 18 metres above ground level and which—
(i)contains one or more dwellings;
(ii)contains an institution; or
(iii)contains a room for residential purposes(excluding any room in a hostel, hotel or boarding house); and
(b)“above ground level” in relation to a storey means above ground level when measured from the lowest ground level adjoining the outside of a building to the top of the floor surface of the storey.
The external envelope of a building should not contribute to undue fire spread from one part of a
building to another part. This intention can be met by constructing external walls so that both of
the following are satisfied.
a. The risk of ignition by an external source to the outside surface of the building and spread of
fire over the outside surface is restricted.
b. The materials used to construct external walls, and attachments to them, and how they are
assembled do not contribute to the rate of fire spread up the outside of the building.
The extent to which this is necessary depends on the height and use of the building.
The external envelope of a building should not provide a medium for undue fire spread to
adjacent buildings or be readily ignited by fires in adjacent buildings. This intention can be met by
constructing external walls so that all of the following are satisfied.
a. The risk of ignition by an external source to the outside surface of the building is restricted.
b. The amount of thermal radiation that falls on a neighbouring building from window openings
and other unprotected areas in the building on fire is not enough to start a fire in the other
building.
c. Flame spread over the roof and/or fire penetration from external sources through the roof is
restricted.
The extent to which this is necessary depends on the use of the building and its position in relation
to adjacent buildings and therefore the site boundary.
Access and facilities for the fire service
B5.(1)The building shall be designed and constructed so as to provide reasonable facilities to assist fire fighters in the protection of life.
(2)Reasonable provision shall be made within the site of the building to enable fire appliances to gain access to the building.
Fire safety information 38.
(1) This regulation applies where building work—
(a) consists of or includes the erection or extension of a relevant building; or
(b) is carried out in connection with a relevant change of use of a building, and Part B of Schedule 1 imposes a requirement in relation to the work.
(2) The person carrying out the work shall give fire safety information to the responsible person not later than the date of completion of the work, or the date of occupation of the building or extension, whichever is the earlier.
(3) In this regulation—
(a) “fire safety information” means information relating to the design and construction of the building or extension, and the services, fittings and equipment provided in or in connection with the building or extension which will assist the responsible person to operate and maintain the building or extension with reasonable safety;
(b) a “relevant building” is a building to which the Regulatory Reform (Fire Safety) Order 2005 applies, or will apply after the completion of building work;
(c) a “relevant change of use” is a material change of use where, after the change of use takes place, the Regulatory Reform (Fire Safety) Order 2005 will apply, or continue to apply, to the building; and
(d) “responsible person” has the meaning given by article 3 of the Regulatory Reform (Fire Safety) Order 2005.
The aim of this regulation is to ensure that the person responsible for the building has sufficient
information relating to fire safety to enable them to manage the building effectively. The aim of
regulation 38 will be achieved when the person responsible for the building has all the information
to enable them to do all of the following.
a. Understand and implement the fire safety strategy of the building.
b. Maintain any fire safety system provided in the building.
c. Carry out an effective fire risk assessment of the building.
BS 476-11
BS 476-7
NOTE:
The national classifications do not automatically equate with the transposed classifications in the ‘BS EN 13501-1 classification’ column, therefore products cannot typically assume a European class unless they have been tested accordingly.
NOTE:
A classification of s3, d2 indicates that no limit is set for production of smoke and/or flaming droplets/particles. If a performance for production of smoke and/or flaming droplets/ particles is specified, then only the European classes can be used. For example, a national class may not be used as an alternative to a classification which includes s1, d0.
BS EN 13501-5
BS 476-3
NOTE:
The national classifications do not automatically equate with the transposed classifications
in the European column, therefore products cannot typically assume a European class unless they
have been tested accordingly.
see Table B4
See Table C1
See Appendix C
NOTES:
1. BS EN 13501-2 Classification using data from fire resistance tests, excluding ventilation services.BS EN 13501-3
Classification using data from fire resistance tests on products and elements used in building service installations: fire resisting ducts and fire dampers. BS EN 13501-4 Classification using data from fire resistance tests on components of smoke control systems.
In the European classification:
‘R’ is the resistance to fire in terms of loadbearing capacity.
‘E’ is the resistance to fire in terms of integrity.
‘I’ is the resistance to fire in terms of insulation.
The national classifications do not automatically equate with the alternative classifications in the European column, therefore products cannot typically assume a European class unless they have been tested accordingly.
2. BS 476-20 for general principles,BS 476-21 for loadbearing elements,BS 476-22 for non-loadbearing elements,BS 476-23 for fire-protecting suspended ceilings and BS 476-24 for ventilation ducts.
3. Applies to loadbearing elements only (see paragraph B19).
4. Guidance on increasing the fire resistance of existing timber floors is given in BRE Digest 208.
5. Only if a suspended ceiling meets the appropriate provisions should it be relied on to add to the fire resistance of the floor.
6. Such walls may contain areas that do not need to be fire resisting (unprotected areas). See Section 11.
7. Unless needed as part of a wall in item 5a or 5b.
8. Except for any limitations on uninsulated glazed elements given in Table B5.
NOTES:
For single storey buildings, the periods under the heading ‘Up to 5’ apply. If single storey buildings have basements, for the basement storeys the period appropriate to their depth applies.
* For the floor over a basement or, if there is more than one basement, the floor over the topmost basement, the higher of the period for the basement storey and the period for the ground or upper storey applies.
† For compartment walls that separate buildings, the period is increased to a minimum of 60 minutes.
+ For any floor that does not contribute to the support of the building within a flat of more than one storey, the period is reduced to 30 minutes.
§ For flat conversions, refer to paragraphs 6.5 to 6.7 regarding the acceptability of 30 minutes.
‡ For elements that do not form part of the structural frame, the period is reduced to 90 minutes.
# For elements that protect the means of escape, the period is increased to 30 minutes.
1. Refer to note 1, Table B3 for the specific provisions of test.
2. Blocks of flats with a floor more than 30m above ground level should be fitted with a sprinkler system in accordance with Appendix E.
NOTE:
Sprinklers only need to be provided within the individual flats, they are not required in the common areas such as stairs, corridors or landings when these areas are fire sterile.
3.‘With sprinkler system’ means that the building is fitted throughout with an automatic sprinkler system in accordance with Appendix E.
4. Very large (over 18m in height or with a 10m deep basement) or unusual dwellinghouses are outside the scope of the guidance provided with regard to dwellinghouses.
5. A minimum of 30 minutes in the case of three storey dwellinghouses, increased to 60 minutes minimum for compartment walls separating buildings.
6. Buildings within the ‘office’, ‘shop and commercial’, ‘assembly and recreation’, ‘industrial’ and ‘storage and other non-residential’ (except car parks for light vehicles) purpose groups (purpose groups 3 to 7(a)) require sprinklers where there is a top storey above 30m.
The sprinkler system should be provided in accordance with Appendix E.
7. The car park should comply with the relevant provisions in the guidance on requirement B3, Section 11 of
Approved Document B Volume 2.
8. For the purposes of meeting the Building Regulations, the following types of steel elements are deemed to have satisfied the minimum period of fire resistance of 15 minutes when tested to the European test method.
i. Beams supporting concrete floors, maximum Hp/A=230m-1 operating under full design load.
ii. Free-standing columns, maximum Hp/A=180m-1 operating under full design load.
iii. Wind bracing and struts, maximum Hp/A=210m-1 operating under full design load.
Guidance is also available in BS EN 1993-1-2.
Flats
1. Within the enclosures of a protected entrance hall or protected landing, or within fire resisting separation shown in Section 3, Diagram 3.4.
2. Within either:
a. the enclosures of a protected stairway
b. fire resisting separation shown in Diagram 2.2.
3. Within fire resisting separation either:
a. shown in Diagram 2.4
b. described in paragraph 2.16b.
4. Existing window between an attached/integral garage and the dwellinghouse.
5. Adjacent to an external escape stair (see paragraph 2.17 and Diagram 2.7) or roof escape route (see paragraph 2.13).
6. Between residential/sleeping accommodation and a common escape route (corridor, lobby or stair).
7. Between a protected stairway(1)and either:
a. the accommodation
b. a corridor that is not a protected corridor other than in item 6 above.
8. Between either:
a. a protected stairway(1)and a protected lobby or protected corridor
b. accommodation and a protected lobby other than in item 6 above.
9. Between the accommodation and a protected corridor that forms a dead end,other than in item 6 above.
10.Between accommodation and any other corridor, or sub-dividing corridors,other than in item 6 above.
11. Beside an external escape route.
Table B5
see Table B3
Table B5
12. Beside an external escape stair (see paragraph 3.68 and Diagram 3.11) or roof escape route (see paragraph 3.30).
NOTES:
Items 1 and 8 apply also to single storey buildings.
Fire resisting glass should be marked with the name of the manufacturer and the name of the product.
Further guidance can be found in A Guide to Best Practice in the Specification and Use of Fire-resistant Glazed Systems published by the Glass and Glazing Federation.
1. If the protected stairway is also a protected shaft or a firefighting stair (see Section 15), there may be further
restrictions on the use of glazed elements.
2. Measured vertically from the landing floor level or the stair pitch line.
3. The 100mm limit is intended to reduce the risk of fire spreading from a floor covering.
Effective clear width (door stop to projecting ironmongery)
Effective clear width (door stop to door leaf)
This approved document has been published in two volumes. Volume 1 deals solely with dwellings, including blocks of flats, while Volume 2 deals with all other types of building covered by the Building Regulations
Volume 1 purpose groups
Purpose for which the building or compartment of a building is intended to be used
Residential(dwellings)
1(a)(1)Flat.
1(b)(2)Dwellinghouse that contains a habitable storey with a floor level a minimum of 4.5m above ground level up to a maximum of 18m.
(3)1(c)(2)(4)Dwellinghouse that does not contain a habitable storey with a floor level a minimum of 4.5m above ground level.
Where Part B applies to existing buildings, particularly buildings of special architectural or historic interest for which the guidance in this document might prove too restrictive, some variation of the provisions in this document may be appropriate. In such cases, it is appropriate to assess the hazard and risk in the particular case and consider a range of fire safety features in that context.
While many of the provisions in this approved document for means of escape from flats are applicable to sheltered housing, the nature of the occupancy may necessitate some additional fire protection measures. The extent of such measures will depend on the form of the development. For example, a group of specially adapted bungalows or two storey flats, with few communal facilities, will not need to be treated differently from other single storey or two storey dwellinghouses or flats.
Fire safety engineering might provide an alternative approach to fire safety. Fire safety engineering may be the only practical way to achieve a satisfactory standard of fire safety in some complex buildings and in buildings that contain different uses.
Fire safety engineering may also be suitable for solving a specific problem with a design that otherwise follows the provisions in this document.
BS 7974 and supporting published documents (PDs) provide a framework for and guidance on the application of fire safety engineering principles to the design of buildings.
Building uses are classified within different purpose groups, which represent different levels of hazard (see Table 0.1). A purpose group can apply to a whole building or a compartment within the building, and should relate to the main use of the building or compartment.
Where a building or compartment has more than one use, it is appropriate to assign each different use to its own purpose group in the following situations.
a. If the ancillary use is a flat.
b. If both of the following apply.
i. The building or compartment has an area of more than 280m2.
ii. The ancillary use relates to an area that is more than one-fifth of the total floor area of the building or compartment.
c. In ‘shop and commercial’ (purpose group 4) buildings or compartments, if the ancillary use is storage and both of the following apply.
i. The building or compartment has an area of more than 280m2.
ii. The storage area comprises more than one-third of the total floor area of the building or compartment.
Where there are multiple main uses that are not ancillary to one another (for example, shops with independent offices above), each use should be assigned to a purpose group in its own right.
Where there is doubt as to which purpose group is appropriate, the more onerous guidance should be applied.
In sheltered housing, the guidance in Approved Document B Volume 2 should be consulted for the design of communal facilities, such as a common lounge.
This approved document includes reference to selected guidance for buildings other than dwellings. For the design of mixed use buildings, Approved Document B Volume 2 should be consulted in addition to the guidance contained in this approved document.
Where a complex mix of uses exists, the effect that one use may have on another in terms of risk should be considered. It could be necessary to use guidance from both volumes, apply other guidance (such as from HTM 05-02 or Building Bulletin 100), and/or apply special measures to reduce the risk.
Requirements B1–B5 of Schedule 1 to the Building Regulations are dealt with separately in one or more sections. Each requirement is shown at the start of the relevant sections.
The provisions in this document have the following aims.
Requirement B1: When there is a fire, ensure both:
a. satisfactory means of sounding an alarm
b. satisfactory means of escape for people.
Requirement B2: Inhibit the spread of fire over internal linings of buildings.
Requirement B3: The building must be built such that all of the following are achieved in the event of a fire:
a. the premature collapse of the building is avoided
b. sufficient fire separation is provided within buildings and between adjoining buildings
c. automatic fire suppression is provided where necessary
d. the unseen spread of fire and smoke in cavities is restricted.
Requirement B4: Restrict both:
a. the potential for fire to spread over external walls and roofs (including compliance with regulations 6(4) and 7(2))
b. the spread of fire from one building to another.
Requirement B5: Ensure both:
a. satisfactory access for the fire service and its appliances
b. facilities in buildings to help firefighters save the lives of people in and around buildings.
Regulation 38: Provide fire safety information to building owners.
Guidance is given on each aspect separately, though many are closely interlinked. The document should be considered as a whole. The relationship between different requirements and their interdependency should be recognised. Particular attention should be given to the situation where one part of the guidance is not fully followed, as this could have a negative effect on other provisions.
The Building Regulations do not impose any requirements on the management of a building, but do assume that it will be properly managed. This includes, for example, keeping protected escape routes virtually ‘fire sterile’.
Appropriate fire safety design considers the way in which a building will be managed. Any reliance on an unrealistic or unsustainable management regime cannot be considered to have met the requirements of the regulations.
Once the building is in use, the management regime should be maintained and a suitable risk assessment undertaken for any variation in that regime. Failure to take proper management responsibility may result in the prosecution of an employer, building owner or occupier under legislation such as the Regulatory Reform (Fire Safety) Order 2005.
The Building Regulations are intended to ensure a reasonable standard of life safety in a fire. The protection of property, including the building itself, often requires additional measures. Insurers usually set higher standards before accepting the insurance risk. Many insurers use the RISC Authority Design Guide for the Fire Protection of Buildings by the Fire Protection Association (FPA) as a basis for providing guidance to the building designer on what they require. Further information on the protection of property can be obtained from the FPA website: www.thefpa.co.uk.
The fire safety aspects of the Building Regulations aim to achieve reasonable standards of health and safety for people in and around buildings. People, regardless of ability, age or gender, should be able to access buildings and use their facilities. The fire safety measures incorporated into a building should take account of the needs of everyone who may access the building, both as visitors and as people who live or work in it. It is not appropriate, except in exceptional circumstances, to assume that certain groups of people will be excluded from a building because of its use. The provisions in this approved document are considered to be of a reasonable standard for most buildings. However, some people’s specific needs might not be addressed. In some situations, additional measures may be needed to accommodate these needs. This should be done on a case- by-case basis.
The fire safety requirements of the Building Regulations will probably be satisfied by following the relevant guidance in this approved document. However, approved documents provide guidance for some common building situations, and there may be alternative methods of complying with the Building Regulation requirements. If alternative methods are adopted, the overall level of safety should not be lower than the approved document provides. It is the responsibility of those undertaking the work to demonstrate compliance. If other standards or guidance documents are adopted, the relevant fire safety recommendations in those publications should be followed in their entirety. However, in some circumstances it may be necessary to use one publication to supplement another. Care must be taken when using supplementary guidance to ensure that an integrated approach is used in any one building. Guidance documents intended specifically for assessing fire safety in existing buildings often include less onerous provisions than those for new buildings and are therefore unlikely to be appropriate for building work that is controlled by the Building Regulations. Buildings for industrial and commercial activities that present a special fire hazard, e.g. those that sell fuels, may require additional fire precautions to those in this approved document.
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.
In student residences that are designed and occupied as a block of flats, separate automatic detection should be provided in each self-contained flat where all of the following apply.
a. A group of up to six students shares the flat.
b. Each flat has its own entrance door.
c. The compartmentation principles for flats in Section 7 have been followed.
Where a total evacuation strategy is adopted, the alarm system should follow the guidance for buildings other than dwellings in Volume 2 of Approved Document B.
The fire detection and alarm systems in flats should connect to a central monitoring point or alarm
receiving centre. The systems should alert the warden or supervisor and identify the individual flat
where a fire has been detected.
These provisions do not apply to the following.
a. The common parts of a sheltered housing development, such as communal lounges.
b. Sheltered accommodation in the 'residential (institutional)' or 'residential (other)' purpose groups (purpose group 2(a) or 2(b)).
In these parts, means of warning should follow the guidance for buildings other than dwellings in Volume 2 of Approved Document B.
Fire detection and alarm systems must be properly designed, installed and maintained. A design,
installation and commissioning certificate should be provided for fire detection and alarm systems.
Third party certification schemes for fire protection products and related services are an effective
means of providing assurances of quality, reliability and safety.
Fire detection and alarm systems sometimes trigger other systems. The interface between systems
must be reliable. Particular care should be taken if the interface is facilitated via another system.
Where any part of BS 7273 applies to the triggering of other systems, the recommendations of that
part of BS 7273 should be followed.
Smoke alarms should be mains operated and conform to BS EN 14604.
Heat alarms should be mains operated and conform to BS 5446-2.
Smoke and heat alarms should have a standby power supply, such as a battery (rechargeable
or non-rechargeable) or capacitor. More information on power supplies is given in clause 15 of
BS 5839-6.
NOTE: The term ‘fire alarm system’ describes the combination of components for giving an audible
and/or other perceptible warning of fire.
NOTE: In this document, the term ‘fire detection system’ describes any type of automatic sensor
network and associated control and indicating equipment. Sensors may be sensitive to smoke,
heat, gaseous combustion products or radiation. Automatic sprinkler systems can also be used to
operate a fire alarm system.
A large dwellinghouse has more than one storey, and at least one storey exceeds 200m2.
A large dwellinghouse of two storeys (excluding basement storeys) should be fitted with a Grade A
Category LD3 fire detection and alarm system, as described in BS 5839-6.
A large dwellinghouse of three or more storeys (excluding basement storeys) should be fitted with
a Grade A Category LD2 fire detection and alarm system as described in BS 5839-6.
Table 10.1 Reaction to fire performance of external surface of walls
‘Relevant buildings’ as defined in regulation 7(4) (see paragraph 10.10)
NOTES:
In addition to the requirements within this table, buildings with a top occupied storey above 18m should also meet the provisions of paragraph 10.6.
In all cases, the advice in paragraph 10.4 should be followed.
1. The restrictions for these buildings apply to all the materials used in the external wall and specified attachments (see paragraphs 10.9 to 10.12 for further guidance).
2. Profiled or flat steel sheet at least 0.5 mm thick with an organic coating of no more than 0.2mm thickness is also acceptable.
3. Timber cladding at least 9mm thick is also acceptable.
4. 10m is measured from the top surface of the roof.
The following assumptions enable a reasonable standard of resistance to the spread of fire to be specified.
a. The size of a fire depends on the compartmentation within the building. A fire may involve a complete compartment, but will not spread to other compartments.
b. The intensity of a fire is related to the building use, but can be moderated by a sprinkler system.
c. Fires in ‘residential’ and ‘assembly and recreation’ buildings (purpose groups 1, 2 and 5) represent a greater risk to life.
d. A building on the far side of the relevant boundary meets both of the following conditions.
i. Has a similar elevation to the one in question.
ii. Is the same distance as the one in question from the common boundary.
e. The radiated heat passing through any part of the fire resisting external wall may be discounted.
Wall sufficiently distant from relevant boundary to be a 100% unprotected area
Wall on or very close to the relevant boundary: very limited amounts of unprotected area
Wall not on, or not very close to, but not sufficiently far from relevant boundary that it can be a wholly unprotected area
Amount of unprotected area dependent on distance from relevant boundary
See para 11.4
NOTES:
Intermediate values may be obtained by interpolation.
1.The total percentage of unprotected area is found by dividing the total unprotected area by the area of a rectangle that encloses all the unprotected areas, and multiplying the result by 100.
In an otherwise protected wall, small unprotected areas may be ignored where they meet the conditions in Diagram 11.5.
Where both of the following apply, separation distances may be determined from the wall rather than from the edge of the canopy (Diagram 11.6).
a. The canopy is attached to the side of a building.
b. The edges of the canopy are a minimum of 2m from the relevant boundary.
Canopies that fall within class 6 or class 7 of Schedule 2 to the regulations (Exempt Buildings and Work) are exempt from the Building Regulations.
Space separation may be disregarded if a canopy is all of the following.
a. Free-standing.
b. Above a limited risk or controlled hazard.
c. A minimum of 1000mm from the relevant boundary.
Where regulation 7(2) applies, that regulation prevails over the provisions within this section.
This boundary coincides with and is therefore relevant to side A
The boundary is parallel to side B2
But the relevant boundary may be the centre line of a road, railway, canal or river
NOTES:
This boundary is at less than 80 degrees to side C and is therefore relevant to side C
This diagram sets out the rules that apply in respect of a boundary for it to be considered as a relevant boundary.
For a boundary to be relevant it should comply with one of the following:
a. Coincide with the side of the building (A).
b. Be parallel to the side of the building (B1 or B2).
c. Be at an angle of maximum 80 degrees to the side of the building (C).
This boundary is parallel to and therefore relevant to side B1
See para 11.5
If a reduced separation distance between buildings, or increased amount of unprotected area, is required, smaller compartments should be considered.
NOTES:
The notional boundary should be set in the area between the two buildings using the following rules:
1. The notional boundary is assumed to exist in the space between the buildings and is positioned so that one of the buildings would comply with the provisions for space separation having regard to the amount of its unprotected area. In practice, if one of the buildings is existing, the position of the boundary will be set by the space separation factors for that building.
2. The siting of the new building, or the second building if both are new, can then be checked to see that it also complies, using the notional boundary as the relevant boundary for the second building.
Notional boundary
Site boundary
Compliance with the provisions for space separation in respect of building A
Compliance with the provisions for space separation in respect of building B
See para 11.5
The fire resistance of a wall depends on its distance from the relevant boundary (see Diagram 11.1). Separation distances are measured to boundaries to ensure that the location and design of buildings on adjoining sites have no influence on the building under consideration.
Area of fire resisting wall with materials more than 1mm thick and with a reaction to fire performance worse than class B-s3, d2 = a x b
Area of wall counted as unprotected area = 0.5a x b
Area of fire resisting wall with materials having a reaction to fire performance better than class B-s3, d2
See para 11.7
The unprotected area of the external wall of a stairway forming a protected shaft may be disregarded for separation distance purposes
Roofs pitched at an angle of less than 70 degrees may be disregarded for separation distance purposes
Represents an unprotected area of not more than 1m2 which may consist of two or more smaller areas within an area of 1000mm X 1000mm
Represents an area of not more than 0.1m2
See para 11.11
Parts of an external wall with less fire resistance than the appropriate amount given in Appendix B, Table B4, are called unprotected areas.
NOTE: Projections from the building line, such as a canopy or a loading platform, can be ignored when assessing separation distance. This does not apply where the canopy is enclosed by side walls.
Distance to relevant boundary measured from building line
See para 11.12
Minimum distance (a) between side of building and relevant boundary (m) Maximum total area of unprotected areas (m2)
See para 11.18
Unprotected areas should meet the conditions in Diagram 11.5, and the rest of the wall should be fire resisting from both sides.
External surface materials facing the boundary should be class B-s3, d2 or better.
Unprotected areas should not exceed the result given by one of the methods in paragraph 11.16, and the rest of the wall (if any) should be fire resisting but only from the inside of the building.
‘Roof covering’ describes one or more layers of material, but not the roof structure as a whole.
NOTES:
1.There are restrictions on the use of plastic rooflights in the guidance to requirement B2 in Section 4.
2.Surrounding roof covering to be a material of class A2-s3, d3 or better for at least 3m distance.
3.Where Diagram 5.2a or 5.2b applies, rooflights should be at least 1500mm from the compartment wall.
See paras 12.5 and 12.6
NOTES:
Separation distances do not apply to the boundary between roofs of a pair of semi-detached dwellinghouses and to enclosed/covered walkways. However, see Diagram 5.2 if the roof passes over the top of a compartment wall.
Polycarbonate and uPVC rooflights that achieve a class C-s3, d2 rating by test may be regarded as having a BROOF(t4) designation.
1. The designation of external roof surfaces is explained in Appendix B.
2. Not acceptable on any of the following buildings.
a. Dwellinghouses in terraces of three or more dwellinghouses.
b. Any other buildings with a cubic capacity of more than 1500m3.
3. Acceptable on buildings not listed in (1) if both of the following apply.
a. Part of the roof has a maximum area of 3m2 and is a minimum of 1500mm from any similar part.
b. The roof between the parts is covered with a material rated class A2-s3, d2 or better.
Provisions for the fire properties of roofs are given in other parts of this document.
a. Requirement B1 – for roofs that are part of a means of escape.
b. Requirement B2 – for the internal surfaces of rooflights as part of internal linings.
c. Requirement B3 – for roofs that are used as a floor and for roofs passing over a compartment wall.
d. Section 11 – the circumstances in which a roof is subject to the provisions for space separation.
NOTES:
None of the above designations are suitable for protected stairways.
Polycarbonate and uPVC rooflights that achieve a class C-s3, d2 rating by test (see paragraph 12.7) may be regarded as having a BROOF(t4) classification.
Where Diagram 5.2a or 5.2b applies, rooflights should be a minimum of 1500mm from the compartment wall.
If double-skinned or laminate products have upper and lower surfaces of different materials, the greater distance applies.
1. See also the guidance to requirement B2 in Section 4.
2. The designation of external roof surfaces is explained in Appendix B.
3. Single-skinned rooflight only, in the case of non-thermoplastic material.
4. The rooflight should also meet the provisions of Diagram 12.1.
Separation distance is the minimum distance from the roof, or part of the roof, to the relevant boundary (paragraph 11.4). Table 12.1 sets out separation distances by the type of roof covering and the size and use of the building.
In addition, roof covering products (and/or materials) defined in Commission Decision 2000/553/ EC of 6 September 2000, implementing Council Directive 89/106/EEC, can be considered to fulfil all of the requirements for the performance characteristic ‘external fire performance’ without the need for testing, provided that any national provisions on the design and execution of works are fulfilled, and can be used without restriction.
NOTES:
None of the above designations are suitable for protected stairways.
Polycarbonate and uPVC rooflights that achieve a class C-s3, d2 rating by test (paragraph 12.7) may be regarded as having a BROOF(t4) classification.
Where Diagram 5.2a or 5.2b applies, rooflights should be a minimum of 1500mm from the compartment wall.
If double-skinned or laminate products have upper and lower surfaces of different materials, the greater distance applies.
1. See also the guidance to requirement B2 in section 4.
2. No limit in the case of any space described in 2a, b and c.
3. Single-skinned rooflight only, in the case of non-thermoplastic material.
4. The rooflight should also meet the provisions of diagram 12.1.
The performance of rooflights is specified in a similar way to the performance of roof coverings. Plastic rooflights may also be used.
Table 12.2 and Diagram 12.1 set the limitations for using plastic rooflights whose lower surface has a minimum class D-s3, d2 rating.
Table 12.3 sets the limitations for using thermoplastic materials with a TP(a) rigid or TP(b) (see also Diagram 12.1) classification. The method of classifying thermoplastic materials is given in Appendix B.
Other than for the purposes of Diagram 5.2, polycarbonate or uPVC rooflights achieving a minimum rating of class C-s3, d2 can be regarded as having a BROOF(t4) classification.
When used in rooflights, unwired glass a minimum of 4mm thick can be regarded as having a BROOF(t4) classification.
If the performance of thatch or wood shingles cannot be established, they should be regarded as having an EROOF(t4) classification in Table 12.1.
NOTE: Consideration can be given to thatched roofs being closer to the relevant boundary than shown in Table 12.1 if, for example, all of the following precautions (based on the LABC publication Thatched Buildings (the Dorset Model): New Properties and Extensions) are incorporated in the design.
a. The rafters are overdrawn with construction having not less than 30 minutes’ fire resistance.
b. The guidance given in Approved Document J is followed.
c. The smoke alarm installation (see Section 1) extends to the roof spaces.
Fire and rescue service vehicles should not have to reverse more than 20m from the end of an access road.
Turning circle, hammerhead or other point at which vehicle can turn
See para 13.4
NOTES:
1. Fire appliances are not standardised. The building control body may, in consultation with the local fire and rescue service, use other dimensions.
2. The road base can be designed to 12.5 tonne capacity. Structures such as bridges should have the full 17-tonne capacity. The weight of high reach appliances is distributed over a number of axles, so infrequent use of a route designed to accommodate 12.5 tonnes should not cause damage.
For flats, either of the following provisions should be made.
a. Provide access for a pumping appliance to within 45m of all points inside each flat of a block, measured along the route of the hose. Every elevation to which vehicle access is provided should have a suitable door(s), not less than 750mm wide, giving access to the interior of the building. Door(s) should be provided such that there is no more than 60m between each door and/or the end of that elevation (e.g. a 150m elevation would need at least two doors).
b. Provide fire mains in accordance with paragraphs 13.5 and 13.6.
Access routes and hardstandings should comply with the guidance in Table 13.1.
Dead-end access routes longer than 20m require turning facilities, as in Diagram 13.1. Turning facilities should comply with the guidance in Table 13.1.
For buildings fitted with wet fire mains, access for a pumping appliance should comply with both of the following.
a. Within 18m, and within sight, of an entrance giving access to the fire main.
b. Within sight of the inlet to replenish the suction tank for the fire main in an emergency.
Fire mains are installed for the fire and rescue service to connect hoses for water. They may be either of the following.
a. The ‘dry’ type, which are both of the following.
i. Normally kept empty.
ii. Supplied through a hose from a fire and rescue service pumping appliance.
b. The ‘wet’ type, which are both of the following.
i. Kept full of water.
ii. Supplied by pumps from tanks in the building.
There should be a facility to replenish a wet system from a pumping appliance in an emergency.
Each fire hydrant should be clearly indicated by a plate, fixed nearby in a conspicuous position, in accordance with BS 3251.
Guidance on aspects of the provision and siting of private fire hydrants is given in BS 9990.
An alternative source of water should be supplied where any of the following apply.
a. No piped water supply is available.
b. Pressure and flow in the water main are insufficient.
c. An alternative source of supply is proposed.
The alternative source of water supply should be one of the following, subject to consultation with the local fire and rescue service.
a. A charged static water tank with a minimum capacity of 45,000 litres.
b. A spring, river, canal or pond that is capable of fulfilling both of the following conditions.
i. Providing or storing a minimum of 45,000 litres of water at all times.
ii. Providing access, space and a hardstanding for a pumping appliance.
c. Any other water supply that the local fire and rescue service considers appropriate.
Buildings with firefighting shafts should have fire mains provided in both of the following.
a. The firefighting stairs.
b. Where necessary, in protected stairways.
The criteria for providing firefighting shafts and fire mains are given in Section 15.
Buildings without firefighting shafts should be provided with fire mains where fire service vehicle access is not provided in accordance with paragraph 13.2(a). In these cases, the fire mains should be located within the protected stairway enclosure, with a maximum hose distance of 45m from the fire main outlet to the furthest point inside each flat, measured on a route suitable for laying a hose.
The outlets from fire mains should be located within the protected stairway enclosure (see Diagram 15.1).
Guidance on the design and construction of fire mains is given in BS 9990.
Buildings with a storey more than 50m above fire service vehicle access level should be provided with wet fire mains. In all other buildings where fire mains are provided, either wet or dry fire mains are suitable.
Fire service vehicle access to fire mains should be provided as described in paragraphs 13.5 and 13.6.
A building requires additional fire hydrants if both of the following apply.
a. It has a compartment with an area of more than 280m2.
b. It is being erected more than 100m from an existing fire hydrant.
If additional hydrants are required, these should be provided in accordance with the following.
a. For buildings provided with fire mains – within 90m of dry fire main inlets.
b. For buildings not provided with fire mains – hydrants should be both of the following.
i. Within 90m of an entrance to the building.
ii. A maximum of 90m apart.
In low rise buildings without deep basements, access for firefighting personnel is typically achieved by providing measures for fire service vehicle access in Section 13 and means of escape.
Minimum fire resistance REI60 from both sides with E30 Sa fire doors
Minimum fire resistance REI 120 from accommodation side and REI60 from inside the shaft with E60 Sa fire doors
NOTES:
1.Outlets from a fire main should be located in the firefighting lobby or, in the case of a shaft serving flats, in the firefighting stairway (see Diagram b).
2.Smoke control should be provided in accordance with BS9999 or, where the firefighting shaft only serves flats, the provisions for smoke control given in paragraph 3.49 may be followed instead.
3.A firefighting lift is required if the building has a floor more than 18m above, or more than 10m below, fire service vehicle access level.
4.This diagram is only to illustrate the basic components and is not meant to represent the only acceptable layout. The firefighting shaft should be constructed generally in accordance with section 6 of BS 9999.
5.For the minimum fire resistance of lift doors see Table C1.
See paras 15.2,15.8 and 15.9
All firefighting shafts should have fire mains with outlet connections and valves at every storey.
A firefighting lift installation includes all of the following.
a. Lift car.
b. Lift well.
c. Lift machinery space.
d. Lift control system.
e. Lift communications system.
The lift shaft should be constructed in accordance with Section 6 of BS 9999.
Firefighting lift installations should conform to BS EN 81-72 and BS EN 81-20.
The fire and rescue service should be able to manually open and close rolling shutters without the use of a ladder.
A building with a storey more than 18m above the fire and rescue service vehicle access level should have one or more firefighting shafts, each containing a firefighting lift (Diagram 15.1). The number and location of firefighting shafts should comply with paragraphs 15.4 to 15.7. Firefighting shafts are not required to serve a basement that is not large or deep enough to need one (see paragraph 15.3 and Diagram 15.2).
Buildings in which firefighting shafts should be provided,
showing which storeys need to be served >18m >10m
a. Any building The upper storeys in any building with a storey more than 18m above fire service vehicle access level
b. Any building The basement storeys in any building with a basement more than 10m below fire service vehicle access level
c. Any building The basement storey(s) in any building with two or more basements each exceeding 900m2
Fire service vehicle access level
Two or more basement storeys each exceeding 900m2
Extent of firefighting Extent of firefighting lift stair
NOTES:
1.Height excludes any top storey(s) consisting exclusively of plant rooms.
2.Firefighting shafts should serve all floors through which they pass.
See para 15.2
A building with basement storeys should have firefighting shafts in accordance with the following.
a. There is a basement more than 10m below the fire and rescue service vehicle access level. The firefighting shafts should contain firefighting lifts.
b. There are two or more basement storeys, each with a minimum area of 900m2. The firefighting shafts do not need to include firefighting lifts.
The building’s height and size determine whether firefighting shafts also serve upper storeys.
NOTES:
1.Hose laying distance should be measured from the fire main outlet along the route suitable for laying hose. If this route is not known, the distance should be taken at two-thirds of the direct distance
2.The fire main outlet should be located according to Section 14.
See para 15.7
Firefighting shafts should serve all storeys through which they pass.
Firefighting shafts and protected stairways should be positioned such that every part of each storey more than 18m above the fire and rescue service vehicle access level complies with the maximum distances given in paragraph 15.7. Distances should be measured from the fire main outlet on a route suitable for laying a hose.
NOTE: If the internal layout is not known, the distance should be measured at two-thirds of the direct distance.
In any building, the hose laying distance should meet all of the following conditions.
a. A maximum of 60m from the fire main outlet in a firefighting shaft (see Diagram 15.3).
b. Additionally, where sprinklers have not been provided in accordance with Appendix E, the hose laying distance should be a maximum of 45m from a fire main outlet in a protected stairway (although this does not imply that the protected stairway needs to be designed as a firefighting shaft (see Diagram 15.3)).
Firefighting stairs and firefighting lifts should be approached from either of the following.
a. A firefighting lobby.
b. A protected corridor or protected lobby that complies with the following guidance.
i. Means of escape (Section 3).
ii. Compartmentation (Section 7).
Both the stair and lobby of the firefighting shaft should be provided with a means of venting smoke and heat (see clause 27.1 of BS 9999).
Only services associated with the firefighting shaft, such as ventilation systems and lighting for the firefighting shafts, should pass through or be contained within the firefighting shaft.
Doors of a firefighting lift landing should be a maximum of 7.5m from the door to the firefighting stair (Diagram 15.1).
Firefighting shafts should achieve a minimum fire resistance of REI 120. A minimum of REI 60 is acceptable for either of the following (see Diagram 15.1).
a. Constructions separating the firefighting shaft from the rest of the building.
b. Constructions separating the firefighting stair, firefighting lift shaft and firefighting lobby.
Heat and smoke from basement fires vented via stairs can inhibit access for firefighting personnel. This may be reduced by providing smoke outlets, or smoke vents, which allow heat and smoke to escape from the basement levels to the open air. They can also be used by the fire and rescue service to let cooler air into the basements (Diagram 16.1).
Basement outlet with break-out or openable cover
Stallboard outlet with grille or removable cover
See para 16.1
Outlets should not be placed where they prevent the use of escape routes from the building.
If basement storeys are fitted with a sprinkler system in accordance with Appendix E, a mechanical smoke extraction system may be provided as an alternative to natural venting. Sprinklers do not need to be installed on the other storeys unless needed for other reasons.
Car parks are not normally expected to be fitted with sprinklers (see Section 11 of Approved Document B Volume 2).
The air extraction system should comply with all of the following.
a. It should give at least 10 air changes per hour.
b. It should be capable of handling gas temperatures of 300°C for not less than one hour.
c. It should do either of the following.
i. Be activated automatically if the sprinkler system activates.
ii. Be activated by an automatic fire detection system that conforms to BS 5839-1 (minimum L3 standard).
Further information on equipment for removing hot smoke is given in BS EN 12101-3.
Outlet ducts or shafts, including any bulkheads over them (see Diagram 16.1), should be enclosed in construction of class A1 rating and fire resistance at least equal to that of the element through which they pass.
Natural smoke outlet shafts should be separated from each other using construction of class A1 rating and fire resistance at least equal to that of the storeys they serve, where the shafts are either of the following.
a. From different compartments of the same basement storey.
b. From different basement storeys.
Each basement space should have one or more smoke outlets.
Where this is not practicable (for example, the plan area is deep and the amount of external wall is restricted by adjoining buildings), the perimeter basement spaces may be vented, with other spaces vented indirectly by opening connecting doors. This does not apply for places of special fire hazard (see paragraph 16.7).
If a basement is compartmented, each compartment should have one or more smoke outlets, rather than indirect venting.
A basement storey or compartment containing rooms with doors or windows does not need smoke outlets.
Smoke outlets connecting directly to the open air should be provided from every basement storey, except for any basement storey that has both of the following.
a. A maximum floor area of 200m2.
b. A floor a maximum of 3m below the adjacent ground level.
Strong rooms do not need to be provided with smoke outlets.
Smoke outlets should be both of the following.
a. Sited at high level in either the ceiling or wall of the space they serve.
b. Evenly distributed around the perimeter, to discharge to the open air.
The combined clear cross-sectional area of all smoke outlets should be a minimum of 1/40 of the area of the floor of the storey they serve.
Separate outlets should be provided from places of special fire hazard.
If the smoke outlet terminates at a point that is not readily accessible, it should be kept unobstructed and covered only with a class A1 grille or louvre.
If the smoke outlet terminates in a readily accessible position, it may be covered by a panel, stallboard or pavement light that can be broken out or opened. The position of covered smoke outlets should be suitably indicated.
For building work involving the erection or extension of a relevant building (i.e. a building to which the Regulatory Reform (Fire Safety) Order 2005 applies, or will apply), or the relevant change of use of a building, fire safety information should be given to the responsible person at one of the following times.
a. When the project is complete.
b. When the building or extension is first occupied.
This section is a guide to the information that should be provided. Guidance is in terms of essential information and additional information for complex buildings; however, the level of detail required should be considered on a case-by-case basis.
Basic information on the location of fire protection measures may be sufficient. An as-built plan of the building should be provided showing all of the following.
a. Escape routes – this should include exit capacity (i.e. the maximum allowable number of people for each storey and for the building).
b. Location of fire-separating elements (including cavity barriers in walk-in spaces).
c. Fire doorsets, fire doorsets fitted with a self-closing device and other doors equipped with relevant hardware.
d. Locations of fire and/or smoke detector heads, alarm call points, detection/alarm control boxes, alarm sounders, fire safety signage, emergency lighting, fire extinguishers, dry or wet fire mains and other firefighting equipment, and hydrants outside the building.
e. Any sprinkler systems, including isolating valves and control equipment.
f. Any smoke control systems, or ventilation systems with a smoke control function, including mode of operation and control systems.
g. Any high risk areas (e.g. heating machinery).
Details should be provided of all of the following.
a. Specifications of fire safety equipment provided, including routine maintenance schedules.
b. Any assumptions regarding the management of the building in the design of the fire safety arrangements.
c. Any provision enabling the evacuation of disabled people, which can be used when designing personal emergency evacuation plans.
A detailed record should be provided of both of the following.
a. The fire safety strategy.
b. Procedures for operating and maintaining any fire protection measures. This should include an outline cause and effect matrix/strategy for the building.
Further guidance is available in clause 9 and Annex H of BS 9999.
A detailed record should be provided of both of the following.
a. The fire safety strategy.
A detailed record should be provided of both of the following.
b. Procedures for operating and maintaining any fire protection measures. This should include an outline cause and effect matrix/strategy for the building.
Further guidance is available in clause 9 and Annex H of BS 9999.
The records should include details of all of the following. d. All passive fire safety measures, including all of the following. e. All of the following.
a. The fire safety strategy, including all assumptions in the design of the fire safety systems (such as fire load). Any risk assessments or risk analysis.
b. All assumptions in the design of the fire safety arrangements for the management of the building.
c. All of the following.
i. Escape routes (including occupant load and capacity of escape routes).
ii. Any provision to enable the evacuation of disabled people.
iii. Escape strategy (e.g. simultaneous or phased).
iv. Muster points.
i. Compartmentation (i.e. location of fire-separating elements).
ii. Cavity barriers.
iii. Fire doorsets, including fire doorsets fitted with a self-closing device and other doors equipped with relevant hardware (e.g. electronic security locks).
iv. Duct dampers.
v. Fire shutters.
i. Fire detector heads.
ii. Smoke detector heads.
iii. Alarm call points.
iv. Detection/alarm control boxes.
v. Alarm sounders.
vi. Emergency communications systems.
vii. CCTV.
viii. Fire safety signage.
ix. Emergency lighting.
x. Fire extinguishers.
xi. Dry or wet fire mains and other firefighting equipment.
xii. Other interior facilities for the fire and rescue service.
xiii. Emergency control rooms.
xiv. Location of hydrants outside the building.
xv. Other exterior facilities for the fire and rescue service.
f. All active fire safety measures, including both of the following.
i. Sprinkler system(s) design, including isolating valves and control equipment.
ii. Smoke control system(s) (or heating, ventilation and air conditioning system with a smoke control function) design, including mode of operation and control systems.
g. Any high risk areas (e.g. heating machinery) and particular hazards.
h. Plans of the building as built, showing the locations of the above.
i. Both of the following.
i. Specifications of any fire safety equipment provided, including all of the following.
• Operational details.
• Operators’ manuals.
• Software.
• System zoning.
• Routine inspection, testing and maintenance schedules.
ii. Records of any acceptance or commissioning tests.
j. Any other details appropriate for the specific building.
The records should include details of all of the following.
a. The fire safety strategy, including all assumptions in the design of the fire safety systems (such as fire load). Any risk assessments or risk analysis.
The records should include details of all of the following.
b. All assumptions in the design of the fire safety arrangements for the management of the building.
The records should include details of all of the following.
c. All of the following.
i. Escape routes (including occupant load and capacity of escape routes).
ii. Any provision to enable the evacuation of disabled people.
iii. Escape strategy (e.g. simultaneous or phased).
iv. Muster points.
The records should include details of all of the following.
d. All passive fire safety measures, including all of the following.
i. Compartmentation (i.e. location of fire-separating elements).
ii. Cavity barriers.
iii. Fire doorsets, including fire doorsets fitted with a self-closing device and other doors equipped with relevant hardware (e.g. electronic security locks).
iv. Duct dampers.
v. Fire shutters.
The records should include details of all of the following.
d. All passive fire safety measures, including all of the following.
i. Compartmentation (i.e. location of fire-separating elements).
The records should include details of all of the following.
d. All passive fire safety measures, including all of the following.
ii. Cavity barriers.
The records should include details of all of the following.
d. All passive fire safety measures, including all of the following.
iii. Fire doorsets, including fire doorsets fitted with a self-closing device and other doors equipped with relevant hardware (e.g. electronic security locks).
The records should include details of all of the following.
d. All passive fire safety measures, including all of the following.
iv. Duct dampers.
The records should include details of all of the following.
d. All passive fire safety measures, including all of the following.
iv. Duct dampers.
The records should include details of all of the following.
d. All passive fire safety measures, including all of the following.
v. Fire shutters.
The records should include details of all of the following.
e. All of the following.
i. Fire detector heads.
ii. Smoke detector heads.
iii. Alarm call points.
iv. Detection/alarm control boxes.
v. Alarm sounders.
vi. Emergency communications systems.
vii. CCTV.
viii. Fire safety signage.
ix. Emergency lighting.
x. Fire extinguishers.
xi. Dry or wet fire mains and other firefighting equipment.
xii. Other interior facilities for the fire and rescue service.
xiii. Emergency control rooms.
xiv. Location of hydrants outside the building.
xv. Other exterior facilities for the fire and rescue service.
The records should include details of all of the following.
f. All active fire safety measures, including both of the following.
i. Sprinkler system(s) design, including isolating valves and control equipment.
ii. Smoke control system(s) (or heating, ventilation and air conditioning system with a smoke control function) design, including mode of operation and control systems.
The records should include details of all of the following.
g. Any high risk areas (e.g. heating machinery) and particular hazards.
The records should include details of all of the following.
h. Plans of the building as built, showing the locations of the above.
The records should include details of all of the following.
i. Both of the following.
i. Specifications of any fire safety equipment provided, including all of the following.
• Operational details.
• Operators’ manuals.
• Software.
• System zoning.
• Routine inspection, testing and maintenance schedules.
ii. Records of any acceptance or commissioning tests.
The records should include details of all of the following.
i. Both of the following.
i. Specifications of any fire safety equipment provided, including all of the following.
• Operational details.
• Operators’ manuals.
• Software.
• System zoning.
• Routine inspection, testing and maintenance schedules.
The records should include details of all of the following.
i. Both of the following.
ii. Records of any acceptance or commissioning tests.
The records should include details of all of the following.
j. Any other details appropriate for the specific building.
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 lift well connecting different compartments should form a protected shaft (see Section 7).
In buildings designed for phased evacuation or progressive horizontal evacuation, if the lift well is not within the enclosures of a protected stairway, its entrance should be separated at every storey by a protected lobby (minimum REI 30).
In basements and enclosed car parks, the lift should be within the enclosure of a protected stairway. Otherwise, the lift should be approached only via a protected lobby or protected corridor (minimum REI 30).
If a lift delivers into a protected corridor or protected lobby serving sleeping accommodation and also serves a storey containing a high fire risk (such as a kitchen, communal areas, stores, etc.) then the lift should be separated from the high fire risk area(s) by a protected lobby or protected corridor (minimum REI 30).
A lift shaft serving storeys above ground level should not serve any basement, if either of the following applies.
a. There is only one escape stair serving storeys above ground level and smoke from a basement fire would adversely affect escape routes in the upper storeys.
b. The lift shaft is within the enclosure to an escape stair that terminates at ground level.
Lift machine rooms should be sited over the lift well where possible. Where buildings or part of a building with only one stairway make this arrangement impractical, the lift machine room should be sited outside the protected stairway.
People should be able to rapidly leave the area around the building. Direct access to a street, passageway, walkway or open space should be available. The route away from the building should comply with the following.
a. Be well defined.
b. If necessary, have suitable guarding.
Final exits should not present a barrier for disabled people. Where the route to a final exit does not include stairs, a level threshold and, where necessary, a ramp should be provided.
Final exit locations should be clearly visible and recognisable.
Final exits should avoid outlets of basement smoke vents and openings to transformer chambers, refuse chambers, boiler rooms and similar risks.
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.
Where access from any habitable room to the entrance hall or flat entrance is impossible without passing through another room, all of the following conditions should be met (Diagram 3.4).
a. Bedrooms should be separated from living accommodation by fire resisting construction (minimum REI 30) and fire doorsets (minimum E 20).
b. The alternative exit should be in the part of the flat that contains the bedrooms.
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.
Where more than one escape route is available from a storey (or part of a building), then some of the escape routes from that storey or part of the building may be by way of an external stair provided all of the following conditions are met:
a. There is a at least one internal escape stair from every part of each storey (excluding plant areas).
b. The stair serves a floor not more than 6m above either the ground level or a roof podium which is itself served by an independent protected stairway.
c. The stair meets the provisions in paragraph 3.68.
Any external escape stair should meet all of the following conditions (Diagram 3.11).
a. Doors to the stair should be fire resisting (minimum E 30) and be fitted with a self-closing device, except for a single exit door from the building to the top landing of a downward-leading external stair, provided it is the only door onto the landing.
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 above and 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. Glazing in areas of fire resisting construction should be fixed shut and fire resisting (in terms of integrity but not insulation) (minimum E 30).
e. Stairs more than 6m in height above ground level (e.g. where they are provided above a podium) should be protected from adverse weather. Protection should prevent the build-up of snow or ice but does not require full enclosure.
Access to an external escape stair may be via a flat roof, provided the flat roof meets the requirements of paragraph 3.30.
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)
The construction separating two adjacent protected stairways (or exit passageways leading to different final exits) should be imperforate.
If a building does not meet the criteria of paragraph 3.28, an escape stair forming part of the only escape route from an upper storey should not continue down to serve a basement storey. The basement storey should be served by a separate escape stair.
Where multiple escape stairs serve the upper storeys, only one needs to end at ground level. Other stairs may connect with the basement storeys if there is a protected lobby or a protected corridor between the stairs and accommodation at each basement level.
Except in buildings described in paragraph 3.28, common stairs forming part of the only escape route from a flat should not serve any of the following.
a. Covered car park.
b. Boiler room.
c. Fuel storage space.
d. Other ancillary accommodation of similar fire risk.
Where a common stair is not part of the only escape route from a flat, it may also serve ancillary accommodation from which it is separated by a protected lobby or protected corridor (minimum REI 30).
Where a stair serves an enclosed car park or place of special fire hazard, the lobby or corridor should have 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.
In buildings with a maximum of 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 (minimum REI 30) at each storey.
In buildings with more than three storeys above the ground storey, stairs may serve the flats and other occupancies if all of the following apply.
a. The flat is ancillary to the main use of the building.
b. The flat has an independent alternative escape route.
c. The stair is separated from occupancies on lower storeys by a protected lobby (minimum REI 30) at each of those storeys.
d. The stair enclosure has at least the same standard of fire resistance as the structural elements of the building (see Appendix B, Table B4); if the stair is a firefighting stair, it should comply with the provisions in Section 15 (see also paragraph 3.60).
e. Any automatic fire detection and alarm system fitted in the main part of the building also covers all flats.
f. Any security measures in any parts of the building do not prevent escape at all material times.
A protected stairway should not be used for anything else, except a lift well or electricity meters.
In single stair buildings, electricity meters should be in securely locked cupboards. Cupboards should be separated from the escape route by fire resisting construction.
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
Gas service and installation pipes and meters should not be within a protected stairway, unless installed in accordance with the Pipelines Safety Regulations 1996 and the Gas Safety (Installation and Use) Regulations 1998.
Every protected stairway should lead to a final exit, either directly or via a protected exit passageway. Any protected exit corridor or stair should have the same standard of fire resistance and lobby protection as the stair it serves.
The flights and landings of escape stairs should be constructed of materials achieving class A2-s3, d2 or better in all of the following situations.
a. If the escape stair is the only stair in a building with more than three storeys.
b. If the escape stair is within a basement storey.
c. If the escape stair serves any storey that has a floor level more than 18m above ground or access level.
d. If the escape stair is an external escape stair, except where the stair connects the ground storey or ground level with a floor or flat roof a maximum of 6m above or below ground level.
e. If the escape stair is a firefighting stair.
Materials achieving class B-s3, d2 or worse may be added to the top horizontal surface, except on firefighting stairs.
Further guidance on the construction of firefighting stairs is given in Section 15 (see also paragraph 3.60). Dimensional constraints on the design of stairs are given in Approved Document K.
Single steps on escape routes should be prominently marked. A single step on the line of a doorway is acceptable, subject to paragraph 3.107.
Fixed ladders should not be provided as a means of escape for members of the public. They should only be provided where a conventional stair is impractical, such as for access to plant rooms which are not normally occupied.
Helical stairs and spiral stairs may form part of an escape route provided they are designed in accordance with BS 5395-2. If they are intended to serve members of the public, stairs should be type E (public) stairs.
Fire resistance test criteria are set out in Appendix C. Standards of performance are summarised in Table C1.
If glazed elements in fire resisting enclosures and doors can only meet the required integrity performance, their use is limited. These limitations depend on whether the enclosure forms part of a protected shaft (see Section 7) and the provisions set out in Appendix B, Table B5. If both integrity and insulation performance can be met, there is no restriction in this document on the use or amount of glass.
Glazed elements should also comply with the following, where necessary.
a. If the enclosure forms part of a protected shaft: Section 7.
b. Appendix B, Table B5.
c. Guidance on the safety of glazing: Approved Document K.
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
Doors should be readily openable to avoid undue delay to people escaping. Doors on escape routes (both within and from the building) should comply with paragraphs 3.91 to 3.98. Guidance on door closing and ‘hold open’ devices for fire doorsets is set out in Appendix C.
NOTE: Paragraphs 3.91 to 3.98 do not apply to flat entrance doors.
In general, doors on escape routes (whether or not the doors are fire doorsets) should be either of the following.
a. Not fitted with a lock, latch or bolt fastenings.
b. Fitted only with simple fastenings that are all of the following.
i. Easy to operate; it should be apparent how to undo the fastening.
ii. Operable from the side approached by people escaping.
iii. Operable without a key.
iv. Operable without requiring people to manipulate more than one mechanism.
Doors may be fitted with hardware to allow them to be locked when rooms are empty.
If a secure door is operated by code or combination keypad, swipe or proximity card, biometric data, etc., a security mechanism override should be possible from the side approached by people escaping.
Electrically powered locks should return to the unlocked position in all of the following situations.
a. If the fire detection and alarm system operates.
b. If there is loss of power or system error.
c. If the security mechanism override is activated.
Security mechanism overrides for electrically powered locks should be a Type A call point, as described in BS 7273-4. The call point should be positioned on the side approached by people escaping. If the door provides escape in either direction, a call point should be installed on both sides of the door.
Guidance on door closing and ‘hold open’ devices for fire doorsets is set out in Appendix C.
The door of any doorway or exit should be hung to open in the direction of escape whenever reasonably practicable. It should always be hung to open in the direction of escape if more than 60 people might be expected to use it during a fire.
All doors on escape routes should be hung to meet both of the following conditions.
a. Open by a minimum of 90 degrees.
b. Open with a swing that complies with both of the following.
i. Is clear of any change of floor level, other than a threshold or single step on the line of the doorway.
ii. Does not reduce the effective width of any escape route across a landing.
Any door opening towards a corridor or a stair should be recessed to prevent its swing encroaching on the effective width.
Doors should contain vision panels in both of the following situations.
a. Where doors on escape routes divide corridors.
b. Where doors are hung to swing both ways.
Approved Document M contains guidance about vision panels in doors across accessible corridors and Approved Document K contains guidance about the safety of glazing.
Where revolving doors, automatic doors and turnstiles are placed across escape routes they should comply with one of the following.
a. They are automatic doors of the required width and comply with one of the following conditions.
i. Their failsafe system provides outward opening from any open position.
ii. They have a monitored failsafe system to open the doors if the mains electricity supply fails.
iii. They failsafe to the open position if the power fails.
b. Non-automatic swing doors of the required width are provided immediately adjacent to the revolving or automatic door or turnstile.
Lift wells should comply with one of the following conditions.
a. Be sited within the enclosures of a protected stairway.
b. Be enclosed with fire resisting construction (minimum REI 30) when in a position that might prejudice the means of escape.
The surface linings of walls and ceilings should meet the classifications in Table 4.1.
NOTE:
1.Wallcoverings which conform to BS EN 15102, achieving at least class C-s3, d2 and bonded to a class A2-s3, d2 substrate, will also be acceptable.
a. DIFFUSER FORMING PART OF CEILING
b. DIFFUSER IN FITTING BELOW AND NOT FORMING PART OF CEILING
See para 4.15
Insulating core panels consist of an inner core of insulation sandwiched between, and bonded to, a membrane, such as galvanised steel or aluminium.
Where they are used internally they can present particular problems with regard to fire spread and should meet all of the following conditions.
a. Panels should be sealed to prevent exposure of the core to a fire. This includes at joints and where services penetrate the panel.
b. In high fire risk areas, such as kitchens, places of special fire hazard, or in proximity to where hot works occur, only class A1 cored panels should be used.
c. Fixing systems for all panels should be designed to take account of the potential for the panel to delaminate. For instance, where panels are used to form a suspended ceiling, the fixing should pass through the panel and support it from the lower face.
Guidance on the control of flame spread is given in the following sections.
a. Stairs and landings: Sections 2 and 3 (escape stairs) and Section 15 (firefighting shafts).
b. Exposed surfaces above fire-protecting suspended ceilings: Section 8.
c. Enclosures to above-ground drainage system pipes: Section 9.
Thermoplastic materials that do not meet the classifications in Table 4.1 can be used as described in paragraphs 4.13 to 4.17. No guidance for European fire test performance is currently available, because there is no generally accepted test and classification procedure.
Thermoplastic materials are defined in Appendix B, paragraph B11. Classifications used here are explained in paragraph B13.
Thermoplastic material classified as a TP(a) rigid product may be used to glaze external windows to rooms, but not external windows to circulation spaces. Approved Document K includes guidance on the safety of glazing.
In rooms and circulation spaces other than protected stairways, rooflights may be constructed of thermoplastic material if they comply with both of the following.
a. The lower surface is classified as TP(a) rigid or TP(b).
b. The size and location of the rooflights follow the limits in Table 4.2, Table 12.2 and Table 12.3.
The following paragraphs apply to lighting diffusers forming part of a ceiling. Diffusers may be part of a luminaire or used below sources of light. The following paragraphs do not apply to diffusers of light fittings attached to the soffit of a ceiling or suspended beneath a ceiling (Diagram 4.1).
Diffusers constructed of thermoplastic material may be incorporated in ceilings to rooms and circulation spaces, but not to protected stairways, if both the following conditions are met.
a. Except for the upper surfaces of the thermoplastic panels, wall and ceiling surfaces exposed in the space above the suspended ceiling should comply with paragraph 4.1.
b. Diffusers should be classified as one of the following.
i. TP(a) rigid – no restrictions on their extent.
ii. TP(b) – limited in their extent (see Table 4.2 and Diagram 4.2).
A ceiling constructed from TP(a) flexible panels should meet the following conditions.
a. Have a maximum area of 5m2.
b. Be supported on all sides.
For the purposes of this requirement, a wall includes both of the following.
a. The internal surface of internal and external glazing (except glazing in doors).
b. Any part of a ceiling which slopes at an angle greater than 70 degrees to the horizontal.
NOTES:
1. Upper and lower surfaces of suspended ceiling, between plastic panels, to comply with paragraph 4.1.
2. No restriction on class D-s3, d2 diffusers or rooflights in small rooms.
3. See note 4 to Table 4.2. 5m²
See Table 4.2
NOTES:
1. This table does not apply to products that meet the provisions in Table 4.1.
2. Smaller rooflights and diffusers can be grouped together provided that both of the following satisfy the dimensions in Diagram 4.2 or 4.3.
a. The overall size of the group.
b. The space between one group and any others.
3. Lighting diffusers of TP(a) flexible rating should be used only in panels of a maximum of 5m2 each. See paragraph 4.17.
4. There are no limits on the use of class D-s3, d2 materials in small rooms. See Table 4.1.
5. The minimum 3m separation given in Diagram 4.2 between each 5m2 group must be maintained. Therefore, in some cases, it may not be possible to use the maximum percentage quoted.
For the purposes of this requirement, a wall does not include any of the following.
a. Doors and door frames.
b. Window frames and frames in which glazing is fitted.
c. Architraves, cover moulds, picture rails, skirtings and similar narrow members.
d. Fireplace surrounds, mantle shelves and fitted furniture.
Materials within this zone – at plane of ceiling – should comply with Table 4.1
Rooflights
See Table 4.2
Parts of walls in rooms may be of lower performance than stated in Table 4.1, but no worse than class D-s3, d2. In any one room, the total area of lower performance wall lining should be less than an area equivalent to half of the room’s floor area, up to a maximum of 20m2 of wall lining.
For the purposes of this requirement, a ceiling includes all of the following.
a. Glazed surfaces.
b. Any part of a wall at 70 degrees or less to the horizontal.
c. The underside of a gallery.
d. The underside of a roof exposed to the room below.
For the purposes of this requirement, a ceiling does not include any of the following.
a. Trap doors and their frames.
b. The frames of windows or rooflights and frames in which glazing is fitted.
c. Architraves, cover moulds, picture rails, exposed beams and similar narrow members.
Rooflights should meet the following classifications, according to material. No guidance for European fire test performance is currently available, because there is no generally accepted test and classification procedure.
a. Non-plastic rooflights should meet the relevant classification in Table 4.1.
b. Plastic rooflights, if the limitations in Table 4.2 and Table 12.2 are observed, should be a minimum class D-s3, d2 rating. Otherwise they should meet the relevant classification in Table 4.1.
Any flexible membrane covering a structure, other than an air-supported structure, should comply with Appendix A of BS 7157.
Guidance on the use of PTFE-based materials for tension-membrane roofs and structures is given in the BRE report BR 274.
Fire doors between the garage and dwellinghouse to have a minimum fire resistance of E30 Sa and be fitted with a self-closing device
Wall and any floor between the garage and dwellinghouse to have a minimum fire resistance of REI 30 from the garage side
The door opening threshold should be a minimum of 100mm above garage floor or
Floor to fall away from door to the outside
See paras 5.6 and 5.7
Adjoining buildings should only be separated by walls, not floors. Compartment walls common to two or more buildings should comply with both of the following.
a. Run the full height of the building in a continuous vertical plane.
b. Be continued through any roof space to the underside of the roof (see Diagram 5.2).
A compartment wall should achieve both of the following.
a. Meet the underside of the roof covering or deck, with fire-stopping to maintain the continuity of fire resistance.
b. Be continued across any eaves.
To reduce the risk of fire spreading over the roof from one compartment to another, a 1500mm wide zone of the roof, either side of the wall, should have a covering classified as BROOF(t4), on a substrate or deck of a material rated class A2-s3, d2 or better, as set out in Diagram 5.2a.
Thermoplastic rooflights that, because of paragraph 12.7, are regarded as having a BROOF(t4) classification are not suitable for use in that zone.
Materials achieving class B-s3, d2 or worse used as a substrate to the roof covering and any timber tiling battens, fully bedded in mortar or other suitable material for the width of the wall (Diagram 5.2b), may extend over the compartment wall in buildings that are a maximum of 15m high.
Double-skinned insulated roof sheeting should incorporate a band of material rated class A2-s3, d2 or better, a minimum of 300mm in width, centred over the wall.
As an alternative to the provisions of paragraphs 5.12 to 5.14, the compartment wall may extend through the roof for a minimum of either of the following (see Diagram 5.2c).
a. Where the height difference between the two roofs is less than 375mm, 375mm above the top surface of the adjoining roof covering.
b. 200mm above the top surface of the adjoining roof covering where either of the following applies.
i. The height difference between the two roofs is 375mm or more.
ii. The roof coverings either side of the wall are of a material classified as BROOF(t4).
Cavities in the construction of a building provide a ready route for the spread of smoke and flame, which can present a greater danger as any spread is concealed. For the purpose of this document, a cavity is considered to be any concealed space.
To reduce the potential for fire spread, cavity barriers should be provided for both of the following.
a. To divide cavities.
b. To close the edges of cavities.
Cavity barriers should not be confused with fire-stopping details (Section 9).
Cavity barriers should be provided at all of the following locations.
a. At the edges of cavities, including around openings (such as windows, doors and exit/entry points for services).
b. At the junction between an external cavity wall and every compartment floor and compartment wall.
c. At the junction between an internal cavity wall and every compartment floor, compartment wall or other wall or door assembly forming a fire resisting barrier.
This does not apply where a wall meets the conditions of Diagram 5.3.
It is not appropriate to complete a line of compartment walls by fitting cavity barriers above them. The compartment wall should be extended to the underside of the floor or roof above.
If one element of structure supports or stabilises another, as a minimum the supporting element should have the same fire resistance as the other element.
a. ANY BUILDING OR COMPARTMENT
Roof covering over this distance to be designated BROOF(t4) rated on deck of material of class A2-s3, d2 or better. Roof covering and deck could be composite structure, e.g. profiled steel cladding.
Fire-stopping to be carried up to underside of roof covering, boarding or slab.
Roof covering to be designated BROOF(t4) rated for at least 1500mm either side of wall.
b. RESIDENTIAL (DWELLINGS) AND RESIDENTIAL (OTHER) A MAXIMUM OF 15M HIGH
Boarding (used as a substrate) or timber tiling battens may be carried over the wall provided that they are fully bedded in mortar (or other no less suitable material) where over the wall.
Thermoplastic insulation materials should not be carried over the wall.
Double-skinned insulated roof sheeting with a thermoplastic core should incorporate a band of material of class A2-s3, d2 at least 300mm wide centred over the wall.
Sarking felt may also be carried over the wall.
If roof support members pass through the wall, fire protection to these members for a distance of 1500mm on either side of the wall may be needed to delay distortion at the junction (see paragraph 5.9).
Double-skinned insulated roof sheeting should incorporate a band of material rated class A2-s3, d2 or better, a minimum of 300mm in width, centred over the wall.
If roof support members pass through the wall, fire protection to these members for a distance of 1500mm on either side of the wall may be needed to delay distortion at the junction (see paragraph 5.9).
Fire-stopping to be carried up to underside of roof covering, e.g. roof tiles.
Section X–X
Roof covering to be designated BROOF(t4) rated for at least this distance.
Roofing battens and sarking felt may be carried over the wall.
Fire-stopping to be carried up to underside of roof covering above and below sarking felt.
NOTES:
1. Fire-stopping should be carried over the full thickness of the wall.
2. Fire-stopping should be extended into any eaves.
3. The compartment wall does not necessarily need to be constructed of masonry.
c. ANY BUILDING OR COMPARTMENT
The wall should be extended up through the roof for a height of at least 375mm above the top surface of the adjoining roof covering.
Where there is a height difference of at least 375mm between two roofs or where the roof coverings on either side of the wall are BROOF(t4) rated, the height of the upstand/parapet wall above the highest roof may be reduced to 200mm.
See paras 5.12 to 5.15
Cavity barriers, tested from each side separately, should provide a minimum of both of the following:
a. 30 minutes’ integrity (E 30)
b. 15 minutes’ insulation (I 15).
They may be formed by a construction provided for another purpose if it achieves the same performance.
Cavity barriers in a stud wall or partition, or provided around openings, may be formed of any of the following.
a. Steel, a minimum of 0.5mm thick.
b. Timber, a minimum of 38mm thick.
c. Polythene-sleeved mineral wool, or mineral wool slab, under compression when installed in the cavity.
d. Calcium silicate, cement-based or gypsum-based boards, a minimum of 12mm thick.
These do not necessarily achieve the performance specified in paragraph 5.20.
NOTE: Cavity barriers provided around openings may be formed by the window or door frame, if the frame is constructed of steel or timber of the minimum thickness in (a) or (b), as appropriate.
Cavity barriers should be tightly fitted to a rigid construction and mechanically fixed in position. If this is not possible (e.g. where a cavity barrier joins to slates, tiles, corrugated sheeting or similar materials) the junction should be fire-stopped.
Cavity barriers should be fixed so their performance is unlikely to be made ineffective by any of the following.
a. Movement of the building due to subsidence, shrinkage or temperature change, and movement of the external envelope due to wind.
b. During a fire, collapse of services penetrating the cavity barriers, either by the failure of the supporting system or through degradation of the service itself (e.g. by melting or burning).
c. During a fire, failure of the cavity barrier fixings. (In roof spaces, where cavity barriers are fixed to roof members, there is no expectation of fire resistance from roof members provided for the purpose of support.)
d. During a fire, failure of any material or construction to which cavity barriers abut. (For example, a suspended ceiling that continues over a fire resisting wall or partition collapses, and the cavity barrier fails prematurely because the ceiling was not designed to provide a minimum fire resistance of EI 30.)
Openings should be limited to the following.
a. Fire doorsets with a minimum E 30 rating, fitted in accordance with Appendix C.
b. The passage of pipes that follow the provisions in Section 9.
c. The passage of cables or conduits containing one or more cables.
d. Openings fitted with a suitably mounted and appropriate fire damper.
e. Ducts that are either of the following.
i. Fire resisting (minimum E 30).
ii. Fitted with a suitably mounted and appropriate fire damper where they pass through the cavity barrier.
NOTE: For further guidance on openings in cavity barriers see Section 9.
The following are excluded from the definition of ‘element of structure’.
a. A structure that supports only a roof, unless either of the following applies.
i. The roof performs the function of a floor, such as a roof terrace, or as a means of escape.
ii. The structure is essential for the stability of an external wall that needs to be fire resisting (e.g. to achieve compartmentation or for the purposes of preventing fire spread between buildings).
b. The lowest floor of the building.
c. External walls, such as curtain walls or other forms of cladding, which transmit only self weight and wind loads and do not transmit floor load.
NOTE: In some cases, structural members within a roof may be essential for the structural stability system of the building. In these cases, the structural members in the roof do not just support a roof and must demonstrate the relevant fire resistance for the building as required by paragraph 5.2 above.
NOTES:
1. Materials used to close the cavity in this arrangement do not need to achieve a specific performance in relation to fire resistance.
2. Domestic meter cupboards may be installed provided that the following conditions are met:
a. There are no more than two cupboards per dwelling
b. The openings in the outer wall leaf are not bigger than 800X500mm for each cupboard
c. The inner leaf is not penetrated except by a sleeve not more than 80X80mm, which is fire-stopped.
3. Materials achieving class B-s3, d2 or worse may be placed within the cavity.
See para 5.18
Where adding an additional storey to a two storey single family dwellinghouse, new floors should have a minimum REI 30 fire resistance. Any floor forming part of the enclosure to the circulation space between the loft conversion and the final exit should achieve a minimum rating of REI 30.
The existing first-storey construction should have a minimum rating of R 30. The fire performance may be reduced for integrity and insulation, when both of the following conditions are met.
a. Only one storey is added, containing a maximum of two habitable rooms.
b. The new storey has a maximum total area of 50m2.
Dwellinghouses that are semi-detached or in terraces should be considered as separate buildings. Every wall separating the dwellinghouses should be constructed as a compartment wall (see paragraphs 5.8 to 5.12).
If a garage is attached to or forms an integral part of a dwellinghouse, the garage should be separated from the rest of the dwellinghouse by fire resisting construction (minimum REI 30) (Diagram 5.1).
Where a door is provided between a dwellinghouse and the garage (see Diagram 5.1), it should meet one of the following conditions.
a. The garage floor should be laid such that it falls away from the door to the outside, to allow fuel spills to flow away.
b. The door opening should be a minimum of 100mm above the level of the garage floor.
All compartment walls and compartment floors should achieve both of the following.
a. Form a complete barrier to fire between the compartments they separate.
b. Have the appropriate fire resistance, as given in Appendix B, Table B3 and Table B4.
Timber beams, joists, purlins and rafters may be built into or carried through a masonry or concrete compartment wall if the openings for them are both of the following.
a. As small as practicable.
b. Fire-stopped.
If trussed rafters bridge the wall, failure of the truss due to a fire in one compartment should not cause failure of the truss in another compartment.
The following are excluded from the definition of ‘element of structure’.
a. A structure that supports only a roof, unless either of the following applies.
i. The roof performs the function of a floor, such as for parking vehicles, or as a means of escape.
ii. The structure is essential for the stability of an external wall that needs to be fire resisting (e.g. to achieve compartmentation or for the purposes of preventing fire spread between buildings).
b. The lowest floor of the building.
c. A platform floor.
d. External walls, such as curtain walls or other forms of cladding, which transmit only self weight and wind loads and do not transmit floor load.
NOTE: In some cases, structural members within a roof may be essential for the structural stability system of the building. In these cases, the structural members in the roof do not just support a roof and must demonstrate the relevant fire resistance for the building as required by the note to paragraph 6.1 above.
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.
If a floor is also a compartment floor, see Section 7.
Where an existing dwellinghouse or other building is converted into flats, a review of the existing construction should be carried out. Retained timber floors may make it difficult to meet the relevant provisions for fire resistance.
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.
In a converted building with four or more storeys, the full standard of fire resistance given in Appendix B is necessary.
The diagram shows three common examples which illustrate the principles. The elements enclosing the shaft (unless formed by adjacent external walls) are compartment walls and floors.
The shaft structure (including any openings) should meet the relevant provisions for: compartment walls (see paragraphs 7.5 to7.19), external walls (see sections 10 and 11 and Diagram 3.10).
See para 7.23
Compartment walls not described in paragraphs 7.8 and 7.9 should run the full height of the storey in which they are situated.
Compartment walls in a top storey beneath a roof should be continued through the roof space.
At the junction with another compartment wall or an external wall, the fire resistance of the compartmentation should be maintained. Fire-stopping that meets the provisions in paragraphs 9.24 to 9.29 should be provided.
At the junction of a compartment floor and an external wall with no fire resistance, the external wall should be restrained at floor level. The restraint should reduce movement of the wall away from the floor if exposed to fire.
Compartment walls should be able to accommodate deflection of the floor, when exposed to fire, by either of the following means.
a. Between the wall and floor, provide a head detail that is capable of maintaining its integrity while deforming.
b. Design the wall so it maintains its integrity by resisting the additional vertical load from the floor above.
Where compartment walls are located within the middle half of a floor between vertical supports, the deflection may be assumed to be 40mm unless a smaller value can be justified by assessment. Outside this area, the limit can be reduced linearly to zero at the supports.
For steel beams that do not have the required fire resistance, reference should be made to SCI Publication P288.
The requirements are the same as for dwellinghouses, detailed in paragraphs 5.11 and 5.12.
Materials achieving class B-s3, d2 or worse used as a substrate to the roof covering and any timber tiling battens, fully bedded in mortar or other suitable material for the width of the wall (Diagram 5.2b), may extend over the compartment wall in buildings that are both of the following.
a. A maximum of 15m high.
b. In one of the following purpose groups.
i. All residential purpose groups (purpose groups 1 and 2) other than ‘residential (institutional)’ (purpose group 2(a)).
ii. ‘Office’ (purpose group 3).
iii. ‘Assembly and recreation’ (purpose group 5).
Double-skinned insulated roof sheeting with a thermoplastic core should incorporate a band of material rated class A2-s3, d2 or better, a minimum of 300mm in width, centred over the wall.
As an alternative to the provisions of paragraph 7.16 or 7.17, the compartment wall may extend through the roof for a minimum of either of the following (see Diagram 5.2c).
a. Where the height difference between the two roofs is less than 375mm, 375mm above the top surface of the adjoining roof covering.
b. 200mm above the top surface of the adjoining roof covering where either of the following applies.
i. The height difference between the two roofs is 375mm or more.
ii. The roof coverings either side of the wall are of a material classified as BROOF(t4).
Openings in a compartment wall common to two or more buildings should be limited to those for either of the following.
a. A fire doorset providing a means of escape, which has the same fire resistance as the wall and is fitted in accordance with the provisions in Appendix C.
b. The passage of a pipe that complies with the provisions in Section 9.
Fire resisting construction enclosing these places should achieve minimum REI 30. These walls and floors are not compartment walls and compartment floors.
Fire resistance to protected shaft to be a maximum of REI 60
Fire resistance of construction to be a minimum of REI 30 (including fire doorsets that are a minimum of E 30 Sa)
Fire resistance of glazing to be a minimum of RE 30(including fire doorsets that are a minimum of E 30 Sa)
a. WITH CORRIDOR
b. WITH LOBBY
See para 7.25
Openings should be limited to those for any of the following.
a. Fire doorsets of the appropriate fire resistance, fitted in accordance with the provisions in Appendix C.
b. Pipes, ventilation ducts, service cables, chimneys, appliance ventilation ducts or ducts encasing one or more flue pipes, complying with the provisions in Section 9.
c. Refuse chutes of class A1 construction.
d. Atria designed in accordance with Annexes B and C of BS 9999.
e. Protected shafts that conform to the provisions in the following paragraphs.
Stairs and service shafts connecting compartments should be protected to restrict the spread of fire between the compartments. These are called protected shafts. Walls or floors surrounding a protected shaft are considered to be compartment walls or compartment floors.
Any stair or other shaft passing directly from one compartment to another should be enclosed in a protected shaft. Protected shafts should be used for the following only, but may also include sanitary accommodation and washrooms.
a. Stairs.
b. Lifts.
c. Escalators.
d. Chutes.
e. Ducts.
f. Pipes.
g. Additional provisions apply for both of the following.
i. Protected shafts that are protected stairways: Sections 2 to 4.
ii. Stairs that are also firefighting stairs: Section 15.
The construction enclosing a protected shaft (Diagram 7.1) should do all of the following.
a. Form a complete barrier to fire between the compartments connected by the shaft.
b. Have the appropriate fire resistance given in Appendix B, Table B3, except for uninsulated glazed screens that meet the provisions of paragraph 7.24.
c. Satisfy the provisions for ventilation and the treatment of openings in paragraphs 7.28 and 7.29.
An uninsulated glazed screen may be incorporated in the enclosure to a protected shaft between a stair and a lobby or corridor entered from the stair. The enclosure must conform to Diagram 7.2 and meet all of the following conditions.
a. The standard of fire resistance required for the protected stairway is not more than REI 60.
b. The glazed screen complies with the following.
i. It achieves a minimum rating of E 30.
ii. It complies with the guidance on limits on areas of uninsulated glazing in Appendix B, Table B5.
c. The lobby or corridor is enclosed with fire resisting construction achieving a minimum rating of REI 30.
Where the measures in Diagram 7.2 are not provided, then both of the following apply.
a. The enclosing walls should comply with Appendix B, Table B3.
b. The doors should comply with Appendix B, Table B5.
A protected shaft containing a protected stairway and/or a lift should not also contain either of the following.
a. A pipe that conveys oil, other than in the mechanism of a hydraulic lift.
b. A ventilating duct. Two exceptions are as follows.
i. A duct provided for pressurising the protected stairway to keep it smoke free.
ii. A duct provided only to ventilate the protected stairway.
A pipe that is completely separated from a protected shaft by fire resisting construction is not considered to be contained within that shaft.
In a protected shaft, any pipe carrying natural gas or LPG should be both of the following.
a. Of screwed steel or all-welded steel construction.
b. Installed in accordance with both of the following.
i. The Pipelines Safety Regulations 1996.
ii. The Gas Safety (Installation and Use) Regulations 1998.
A protected shaft conveying piped flammable gas should be ventilated direct to the outside air, by ventilation openings at high and low level in the shaft.
Any extension of the storey floor into the protected shaft should not compromise the free movement of air throughout the entire length of the shaft.
Guidance on shafts conveying piped flammable gas, including the size of ventilation openings, is given in BS 8313.
The external wall of a protected shaft does not normally need to have fire resistance. Situations where there are provisions are given in paragraph 3.63 (external walls of protected stairways, which may also be protected shafts) and paragraphs 15.8 to 15.11 (firefighting shafts).
Openings in other parts of the enclosure to a protected shaft should be limited to the following.
a. If a wall common to two or more buildings forms part of the enclosure, only the following openings should be made in that wall.
i. A fire doorset providing a means of escape, which has the same fire resistance as the wall and is fitted in accordance with the provisions in Appendix C.
ii. The passage of a pipe that meets the provisions in Section 9.
b. Other parts of the enclosure (other than an external wall) should only have openings for any of the following.
i. Fire doorsets of the appropriate fire resistance, fitted in accordance with the provisions in Appendix C.
ii. The passage of pipes which meet the provisions in Section 9.
iii. Inlets to, outlets from and openings for a ventilation duct (if the shaft contains or serves as a ventilating duct), meeting the provisions in Section 9.
iv. The passage of lift cables into a lift machine room (if the shaft contains a lift). If the machine room is at the bottom of the shaft, the openings should be as small as practicable.
Parts of a building occupied mainly for different purposes should be separated from one another by compartment walls and/or compartment floors. Compartmentation is not needed if one of the different purposes is ancillary to the other. See paragraphs 0.18 and 0.19.
All compartment walls and compartment floors should achieve both of the following.
a. Form a complete barrier to fire between the compartments they separate.
b. Have the appropriate fire resistance, as given in Appendix B, Tables B3 and B4.
Timber beams, joists, purlins and rafters may be built into or carried through a masonry or concrete compartment wall if the openings for them are both of the following.
a. As small as practicable.
b. Fire-stopped.
If trussed rafters bridge the wall, failure of the truss due to a fire in one compartment should not cause failure of the truss in another compartment.
Where services could provide a source of ignition, the risk of fire developing and spreading into adjacent compartments should be controlled.
Adjoining buildings should only be separated by walls, not floors. Compartment walls common to two or more buildings should comply with both of the following.
a. Run the full height of the building in a continuous vertical plane.
b. Be continued through any roof space to the underside of the roof (see Diagram 5.2).
Compartment walls forming a separated part of a building should run the full height of the building in a continuous vertical plane.
Separated parts can be assessed independently to determine the appropriate standard of fire resistance in each. The two separated parts can have different standards of fire resistance.
Cavities in the construction of a building provide a ready route for the spread of smoke and flame, which can present a greater danger as any spread is concealed. For the purpose of this document, a cavity is considered to be any concealed space.
Fire-stopping (same resistance as compartment)
Cavity barriers
NOTE:
1. See paragraph 8.5
See para 8.2
To reduce the potential for fire spread, cavity barriers should be provided for both of the following.
a. To divide cavities.
b. To close the edges of cavities.
See Diagram 8.1. Cavity barriers should not be confused with fire-stopping details (Section 9).
NOTES:
1. Materials used to close the cavity in this arrangement do not need to achieve a specific performance in relation to fire resistance.
2. Domestic meter cupboards may be installed provided that the following conditions are met:
a. There are no more than two cupboards per dwelling
b. The openings in the outer wall leaf are not bigger than 800X500mm for each cupboard
c. The inner leaf is not penetrated except by a sleeve not more than 80X80mm, which is fire-stopped.
3. Materials achieving class B-s3, d2 or worse may be placed within the cavity.
See para 8.3
NOTE:
The ceiling should meet the following conditions.
a. Provide a minimum fire resistance of EI 30.
b. Be imperforate, except for an opening described in paragraph 5.24.
c. Extend through out the building or compartment.
d. Not be easily demountable.
See para 8.5
The insulation should make contact with both skins of sheeting. See also Diagram 5.2a regarding the need for fire-stopping where such roofs pass over the top of a compartment wall.
See para 8.7
If the fire resisting construction of a protected escape route is either of the following.
a. Not carried to full storey height.
b. At the top storey, not carried to the underside of the roof covering.
Then the cavity above or below the fire resisting construction should be either of the following.
i. Fitted with cavity barriers on the line of the enclosure.
ii. For cavities above the fire resisting construction, enclosed on the lower side by a fire resisting ceiling (minimum EI 30) that extends throughout the building, compartment or separated part (see Diagram 8.3).
In divided corridors (paragraph 3.25 and following) with cavities, fire-stopping should be provided to prevent alternative escape routes being affected by fire and/or smoke.
Cavity barriers are not required between double-skinned corrugated or profiled insulated roof sheeting, if the sheeting complies with all of the following.
a. The sheeting is rated class A2-s3, d2 or better.
b. Both surfaces of the insulating layer are rated class C-s3, d2 or better.
c. Both surfaces of the insulating layer make contact with the inner and outer skins of cladding (Diagram 8.4).
Cavity barriers, tested from each side separately, should provide a minimum of both of the following:
a. 30 minutes’ integrity (E 30)
b. 15 minutes’ insulation (I 15).
They may be formed by a construction provided for another purpose if it achieves the same performance.
NOTES:
1. The enclosure should meet all of the following conditions.
a. Be bounded by a compartment wall or floor, an outside wall, an intermediate floor or a casing(see specification at 2 below).
b. Have internal surfaces (except framing members)of class B-s3, d2 or better.
Note: when a classification includes ‘s3, d2’, this means that there is no limit set for smoke production and/or flaming droplets/particles).
c. Not have an access panel which opens into a circulation space or bed room.
d. Be used only for drainage or water supply or vent pipes for a drainage system.
2.The casing should meet all the following conditions.
a. Be imperforate except for an opening for a pipe
or an access panel.
b. Not be of sheet metal.
c. Not have fire resistance less than E 30 (including any access panel).
3.The opening for a pipe, in either the element of structure or the casing, should be as small as possible and fire-stopped around the pipe.
See para 9.4 and Table 9.1
NOTES:
1. Any metal (such as cast iron, copper or steel) which, if exposed to a temperature of 800°C, will not soften or fracture to the extent that flame or hot gas will pass through the wall of the pipe.
2. uPVC pipes that comply with either BS 4514 or BS 5255.
3. These diameters are only in relation to pipes that form part of an above-ground drainage system and are enclosed as shown in Diagram 9.1. In other cases, the maximum diameters given for situation 5 apply.
In mixed use buildings, non-domestic kitchens, car parks and plant rooms should have separate and independent extraction systems. Extracted air should not be recirculated.
Under fire conditions, ventilation and air-conditioning systems should be compatible with smoke control systems and need to be considered in their respective design.
Further information on fire resisting ductwork is given in the ASFP Blue Book.
Where ducts pass between fire-separating elements to serve multiple flats or dwellings, fire dampers or fire and smoke dampers should be actuated by both of the following.
a. Smoke detector-controlled automatic release mechanisms.
b. Thermally actuated devices.
Methods 1 and 4 should not be used for extract ductwork serving kitchens. The likely build-up of grease within the duct can adversely affect dampers.
Method 1 should not be used for extract ductwork passing through the enclosures of protected escape routes (Diagrams 9.3 and 9.4), as large volumes of smoke can pass thermal devices without triggering them.
An ES classified fire and smoke damper which is activated by a suitable fire detection system (method 4) may also be used for protected escape routes.
Both fire dampers and fire and smoke dampers should be all of the following.
a. Sited within the thickness of the fire-separating elements.
b. Securely fixed.
c. Sited such that, in a fire, expansion of the ductwork would not push the fire damper through the structure.
Access to the fire damper and its actuating mechanism should be provided for inspection, testing and maintenance.
Pipes passing through a fire-separating element, unless in a protected shaft, should meet one of the alternatives A, B or C below.
NOTES:
1.Make the opening in the structure as small as possible and provide fire-stopping between pipe and structure.
2.See Table 9.1 for materials specification.
3. The sleeve should be class A1 rated.
See para 9.5
Fire dampers should meet both of the following conditions.
a. Conform to BS EN 15650.
b. Have a minimum E classification of 60 minutes or to match the integrity rating of the fire resisting elements, whichever is higher.
Fire and smoke dampers should meet both of the following conditions.
a. Conform to BS EN 15650.
b. Have a minimum ES classification of 60 minutes or to match the integrity rating of the fire resisting elements, whichever is higher.
Smoke detectors should be sited so as to prevent the spread of smoke as early as practicable by activating the fire and smoke dampers. Smoke detectors and automatic release mechanisms used to activate fire dampers and/or fire and smoke dampers should conform to BS EN 54-7 and BS 5839-3 respectively.
Further information on fire dampers and/or fire and smoke dampers is given in the ASFP Grey Book.
The wall of a flue, duct containing flues or appliance ventilation duct(s) should have a fire resistance (REI) that is at least half of any compartment wall or compartment floor it passes through or is built into (Diagram 9.5).
In addition to any other provisions in this section, both of the following conditions should be met.
a. Joints between fire-separating elements should be fire-stopped.
b. Openings through a fire resisting element for pipes, ducts, conduits or cable should be all of the following.
i. As few as possible.
ii. As small as practicable.
iii. Fire-stopped (allowing thermal movement in the case of a pipe or duct).
NOTE: The fire-stopping around fire dampers, fire resisting ducts, fire and smoke dampers and smoke control ducts should be in accordance with the manufacturer or supplier’s installation instructions.
Materials used for fire-stopping should be reinforced with (or supported by) materials rated class A2-s3, d2 or better to prevent displacement in both of the following cases.
a. Where the unsupported span is greater than 100mm.
b. Where non-rigid materials are used (unless subjected to appropriate fire resistance testing to show their suitability).
Proprietary, tested fire-stopping and sealing systems are available and may be used. Different materials suit different situations and not all are suitable in every situation.
Other fire-stopping materials include the following. a. Cement mortar. b. Gypsum-based plaster. c. Cement-based or gypsum-based vermiculite/perlite mixes. d. Glass fibre, crushed rock, blast furnace slag or ceramic-based products (with or without resin binders). e. Intumescent mastics. These may be used in situations appropriate to the particular material. Not all materials will be suitable in every situation.
Guidance on the design, installation and maintenance of measures to contain fires or slow their spread is given in Ensuring Best Practice for Passive Fire Protection in Buildings produced by the Association for Specialist Fire Protection (ASFP).
Further information on generic systems, their suitability for different applications and guidance on test methods, is given in the ASFP Red Book.
Provide a proprietary, tested sealing system that will maintain the fire resistance of the wall, floor or cavity barrier.
NOTE:
Ventilation ducts which serve other parts of the building should not supply or extract air directly to or from a protected escape route.
Ductwork enclosed in fire resisting construction classified EI X in accordance with BSEN13501-2 (fire exposure from the duct side), or fire resisting ductwork classified EIS X in accordance with BS EN 13501-3, where X is the fire resistance rating (in minutes) of the walls of the protected escape route
See para 9.16
Where a proprietary sealing system is not used, fire-stop around the pipe, keeping the opening for the pipe as small as possible. The nominal internal diameter of the pipe should not exceed the relevant dimension given in Table 9.1. The diameter given in Table 9.1 for pipes of specification (b) used in situation 2 or 3 assumes that the pipes are part of an above-ground drainage system and are enclosed as shown in Diagram 9.1. If they are not, the smaller diameter given for situation 5 should be used.
ES leakage rated fire and smoke damper conforming to BS EN 13501-3/BS EN 1366-2
Smoke detection system in accordance with BS 5839-1 to activate ES damper
Ductwork passing through protected escape routes–method 4
NOTE:
Ventilation ducts which serve other parts of the building should not supply or extract air directly to or from a protected escape route.
See para 9.16
A pipe with a maximum nominal internal diameter of 160mm may be used with a sleeve made out of a high melting point metal, as shown in Diagram 9.2, if the pipe is made of one of the following.
a. Lead.
b. Aluminium.
c. Aluminium alloy.
d. Fibre-cement.
e. uPVC (pipes should also comply with either BS 4514 or BS 5255).
A high melting point metal means any metal (such as cast iron, copper or steel) which, if exposed to a temperature of 800°C, will not soften or fracture to the extent that flame or hot gas will pass through the wall of the pipe.
a. Flue passing through compartment wall or floor
b. Flue built into compartment wall
Flue walls should have a fire resistance of at least one half of that required for the compartment wall or floor and be of class A1construction.
In each case flue walls should have a fire resistance of at least one half of that required for the compartment wall and be of class A1 construction.
See para 9.23
Ductwork should not help to transfer fire and smoke through the building. Terminals of exhaust points should be sited away from final exits, cladding or roofing materials achieving class B-s3, d2 or worse and openings into the building.
Ventilation ducts supplying or extracting air directly to or from a protected stairway should not also serve other areas. A separate ventilation system should be provided for each protected stairway.
A fire and smoke damper should be provided where ductwork enters or leaves each section of the protected escape route it serves. It should be operated by a smoke detector or suitable fire detection system. Fire and smoke dampers should close when smoke is detected. Alternatively, the methods set out in paragraphs 9.16 and 9.17 and Diagrams 9.3 and 9.4 may be followed.
In a system that recirculates air, smoke detectors should be fitted in the extract ductwork before both of the following.
a. The point where recirculated air is separated from air to be discharged to the outside.
b. Any filters or other air cleaning equipment.
When smoke is detected, detectors should do one of the following.
i. Cause the system to immediately shut down.
ii. Switch the ventilation system from recirculating mode to extraction to divert smoke to outside the building.
This document uses the European classification system for reaction to fire set out in BS EN 13501-1;
however, there may be some products lawfully on the market using the classification system set
out in previous editions. Where this is the case, Table B1 can be used for the purposes of this
document.
NOTE: The national classifications do not automatically equate with the transposed classifications
in the ‘BS EN 13501-1 classification’ column, therefore products cannot typically assume a European
class unless they have been tested accordingly.
NOTE: A classification of s3, d2 indicates that no limit is set for production of smoke and/or
flaming droplets/particles. If a performance for production of smoke and/or flaming droplets/
particles is specified, then only the European classes can be used. For example, a national class may
not be used as an alternative to a classification which includes s1, d0.
Thermoplastic material is any synthetic polymeric material that has a softening point below 200°C if tested to BS EN ISO 306 Method A120. Products formed from these materials cannot always be classified in the normal way. In those circumstances the following approach can be followed.
Thermoplastic materials used for window glazing, rooflights and lighting diffusers within suspended ceilings do not need to meet the criteria within paragraph B19 onwards, if the guidance to requirements B2 and B4 is followed.
For the purposes of requirements B2 and B4, thermoplastic materials should be classified as TP(a)
rigid, TP(a) flexible or TP(b), as follows:
a. TP(a) rigid
i. rigid solid uPVC sheet
ii. solid (as distinct from double- or multi-skinned) polycarbonate sheet a minimum of 3mm
thick
iii. multi-skinned rigid sheet made from uPVC or polycarbonate that has a class 1 rating when
tested to BS 476-7
iv. any other rigid thermoplastic product, a specimen of which (at the thickness of the
product as put on the market), when tested to BS 2782-0 Method 508A, performs so that
both:
• the test flame extinguishes before the first mark
• the duration of flaming or afterglow does not exceed 5 seconds following removal of
the burner.
b. TP(a) flexible
Flexible products a maximum of 1mm thick that comply with the Type C requirements
of BS 5867-2 when tested to BS 5438 Test 2 with the flame applied to the surface of the
specimens for 5, 15, 20 and 30 seconds respectively, but excluding the cleansing procedure; and
c. TP(b)
i. rigid solid polycarbonate sheet products a maximum of 3mm thick, or multi-skinned
polycarbonate sheet products that do not qualify as TP(a) by test
ii. other products which, when a specimen of the material between 1.5 and 3mm thick is
tested in accordance with BS 2782-0 Method 508A, have a maximum rate of burning of
50mm/minute.
NOTE: If it is not possible to cut or machine a 3mm thick specimen from the product, then a 3mm
A thermoplastic material alone when used as a lining to a wall or ceiling cannot be assumed to protect a substrate. The surface rating of both thermoplastic material and substrate must therefore meet the required classification. If, however, the thermoplastic material is fully bonded to a non-thermoplastic substrate, then only the surface rating of the composite needs to meet the required classification.
Performance of the resistance of roofs to external fire exposure is measured in terms of penetration through the roof construction and the spread of flame over its surface.
Roof constructions are classified within the European system as BROOF(t4), CROOF(t4), DROOF(t4), EROOF(t4) or FROOF(t4) in accordance with BS EN 13501-5. BROOF(t4) indicates the highest performance and FROOF(t4) the lowest.
BS EN 13501-5 refers to four separate roof tests. The suffix (t4) used in paragraph B16 indicates that Test 4 is to be used for the purposes of this approved document.
This document uses the European classification system for roof covering set out in BS EN 13501-5; however, there may be some products lawfully on the market using the classification system set out in previous editions. Where this is the case, Table B2 can be used for the purposes of this document.
Common to all of the provisions of Part B of the Building Regulations is the property of fire
resistance. Fire resistance is a measure of one or more of the following.
a. Resistance to collapse (loadbearing capacity), which applies to loadbearing elements only,
denoted R in the European classification of the resistance to fire performance.
b. Resistance to fire penetration (integrity), denoted E in the European classification of the
resistance to fire performance.
c. Resistance to the transfer of excessive heat (insulation), denoted I in the European
classification of the resistance to fire performance.
Any test evidence used to demonstrate the fire performance classification of a product or system should be carefully checked to ensure that it is applicable to the intended use. Small differences in detail, such as fixing method, joints, dimensions, the introduction of insulation materials and air gaps (ventilated or not), can significantly affect the performance.
The standards of fire resistance necessary for a particular building are based on assumptions about the severity of fires and the consequences should an element fail. Fire severity is estimated in very broad terms from the use of the building (its purpose group), on the assumption that the building contents (which constitute the fire load) are similar for buildings with the same use.
Because the use of buildings may change, a precise estimate of fire severity based on the fire load due to a particular use may be misleading. Therefore if a fire engineering approach of this kind is adopted, the likelihood that the fire load may change in the future needs to be considered.
Performance in terms of the fire resistance to be achieved by elements of structure, doors and
other forms of construction is classified in accordance with one of the following.
a. BS EN 13501-2.
b. BS EN 13501-3.
c. BS EN 13501-4.
Fire resistance is measured in minutes. This relates to time elapsed in a standard test and should not be confused with real time.
The fire resistance necessary for different circumstances is set out in the following tables.
a. Table B3 gives the specific requirements for each element of structure.
b. Table B4 sets out the minimum periods of fire resistance for elements of structure.
c. Table B5 sets out limitations on the use of uninsulated fire resisting glazed elements.
The following guidance should be used when applying the fire resistance standards in Table B4.
a. If one element of structure supports or carries or gives stability to another, the fire resistance
of the supporting element should be no less than the minimum period of fire resistance for the
other element (whether that other element is loadbearing or not). In some circumstances, it
may be reasonable to vary this principle, for example:
i. if the supporting structure is in the open air and is not likely to be affected by the fire in
the building
ii. if the supporting structure is in a different compartment, with a fire-separating element
(that has the higher standard of fire resistance) between the supporting and the separated
structure
iii. if a plant room on the roof needs greater fire resistance than the elements of structure
that support it.
b. If an element of structure forms part of more than one building or compartment, that element
should be constructed to the standard of the higher of the relevant provisions.
c. If, due to the slope of the ground, one side of a basement is open at ground level (allowing
smoke to vent and providing access for firefighting) for elements of structure in that storey
it may be appropriate to adopt the standard of fire resistance that applies to above-ground
structures.
d. Although most elements of structure in a single storey building may not need fire resistance,
fire resistance is needed if one of the following applies to the element.
i. It is part of, or supports, an external wall, and there is provision in the guidance on
requirement B4 to limit the extent of openings and other unprotected areas in the wall.
ii. It is part of, or supports, a compartment wall, including a wall that is common to two or
more buildings.
iii. It supports a gallery.
For the purposes of this paragraph, the ground storey of a building that has one or more basement storeys and no upper storeys may be considered as a single storey building. The fire resistance of the basement storeys should be that specified for basements.
Assessments should not be regarded as a way to avoid a test where one is necessary. Assessments should only be carried out where sufficient relevant test evidence is available. Relevant test evidence is unlikely to be provided by test standards which have different classification criteria.
Tests and assessments should be carried out by organisations with the necessary expertise. For NOTE: Standard fire tests do not directly measure fire hazard. They measure or assess the response
example, organisations listed as ‘notified bodies’ in accordance with the European Construction Products Regulation or laboratories accredited by the United Kingdom Accreditation Service (UKAS)
for the relevant test standard can be assumed to have the necessary expertise.
of a material or system to exposure to one or more aspects of fire conditions. Performance in fire
tests is only one of a number of factors that should be taken into account.
Reaction to fire relates to the degree to which a product will contribute, by its own decomposition, to a fire under specified conditions. Products, other than floorings, are classified as A1, A2, B, C, D, E or F (with class A1 being the highest performance and F being the lowest) in accordance with BS EN 13501-1. Class F is assigned when a product fails to attain class E. Untested products cannot be classified in accordance with BS EN 13501-1. Materials covered by the Classification Without Further Testing (CWFT) process can be found by accessing the European Commission's website https://eur-lex.europa.eu/.
The classes of reaction to fire performance of A2, B, C, D and E are accompanied by additional
classifications related to the production of smoke (s1, s2, s3), with s1 indicating the lowest
production, and/or flaming droplets/particles (d0, d1, d2), with d0 indicating the lowest
production.
NOTE: When a classification includes s3, d2 this means that there is no limit set for smoke
production and/or flaming droplets/particles.
To reduce the testing burden on manufacturers, BS EN 13238 defines a number of standard substrates that produce test results representative of different end use applications. The classification for reaction to fire achieved during testing is only valid when the product is used within this field of application, i.e. when the product is fixed to a substrate of that class in its end use. The standard substrate selected for testing should take account of the intended end use applications (field of application) of the product and represent end use substrates that have a density of a minimum of 75 of the standard substrate's nominal density.
Standard substrates include gypsum plasterboard (BS EN 520) with a density of 700+/-100kg/m3,
calcium silicate board (BS EN 14306) 870+/-50kg/m3 and fibre-cement board 1800+/-200kg/m3.
NOTE: Standard calcium silicate board is not representative of gypsum plasterboard end use (due
to the paper layer), but would be representative of most gypsum plasters (with densities of more
than 650kg/m3).
NOTE: Classifications based on tests using a plasterboard substrate
All fire doorsets should have the performance shown in Table C1, based on one of the following.
a. Fire resistance in terms of integrity, for a period of minutes, when tested to BS 476-22, e.g. FD 30.
A suffix (S) is added for doorsets where restricted smoke leakage at ambient temperatures is
needed.
b. As determined with reference to Commission Decision 2000/367/EC regarding the
classification of the resistance to fire performance of construction products, construction
works and parts thereof. All fire doorsets should be classified in accordance with BS EN 13501-2,
tested to the relevant European method from the following.
i. BS EN 1634-1.
ii. BS EN 1634-2.
iii. BS EN 1634-3.
c. As determined with reference to European Parliament and Council Directive 95/16/EC (which
applies to lifts that permanently serve buildings and constructions and specified safety
components) on the approximation of laws of Member States relating to lifts (‘Lifts Directive’)
implementing the
Unless shown to be satisfactory when tested as part of a fire doorset assembly, the essential components of any hinge on which a fire door is hung should be made entirely from materials that have a minimum melting point of 800°C.
Except for doorsets listed in paragraph C12, all fire doorsets should be marked with one of the
following fire safety signs, complying with BS 5499-5, as appropriate.
a. To be kept closed when not in use – mark ‘Fire door keep shut’.
b. To be kept locked when not in use – mark ‘Fire door keep locked shut’.
c. Held open by an automatic release mechanism or free swing device – mark ‘Automatic fire door
keep clear’.
All fire doorsets should be marked on both sides, except fire doorsets to cupboards and service
ducts, which should be marked on the outside.
The following fire doorsets are not required to comply with paragraph C11.
a. Doors to and within flats and dwellinghouses.
b. Bedroom doors in ‘residential (other)’ (purpose group 2(b)) premises.
c. Lift entrance/landing doors.
The performance of some doorsets set out in Table C1 is linked to the minimum periods of fire resistance for elements of structure given in Tables B3 and B4. Limitations on the use of uninsulated glazing in fire doorsets are given in Table B5.
Recommendations for the specification, design, construction, installation and maintenance of fire
doorsets constructed with non-metallic door leaves are given in BS 8214.
Guidance on timber fire resisting doorsets, in relation to the new European test standard, may be
found in Timber Fire Resisting Doorsets: Maintaining Performance Under the New European Test
Standard published by the Timber Research and Development Association (TRADA).
Guidance for metal doors is given in Code of Practice for Fire Resisting Metal Doorsets published by
the Door and Shutter Manufacturers’ Association (DSMA).
Hardware used on fire doors can significantly affect their performance in a fire. Notwithstanding the guidance in this approved document, guidance is available in Hardware for Fire and Escape Doors published by the Door and Hardware Federation (DHF) and Guild of Architectural Ironmongers (GAI).
The performance requirement is in terms of integrity (E) for a period of minutes. An additional
classification of Sa is used for all doors where restricted smoke leakage at ambient temperatures is
needed.
The requirement is for test exposure from each side of the doorset separately. The exception is lift doors, which are tested from the landing side only.
Any test evidence used to verify the fire resistance rating of a doorset or shutter should be
checked to ensure both of the following.
a. It adequately demonstrates compliance.
b. It is applicable to the complete installed assembly. Small differences in detail may significantly
affect the rating.
Until relevant harmonised product standards are published, for the purposes of meeting the
Building Regulations, products tested in accordance with BS EN 1634-1 (with or without pre-fire test
mechanical conditioning) that achieve the minimum performance in Table C1 will be deemed to
satisfy the provisions.
All fire doorsets, including to flat entrances and between a dwellinghouse and an integral garage,
should be fitted with a self-closing device, except for all of the following.
a. Fire doorsets to cupboards.
b. Fire doorsets to service ducts normally locked shut.
c. Fire doorsets within flats and dwellinghouses.
If a self-closing device would be considered to interfere with the normal approved use of the
building, self-closing fire doors may be held open by one of the following.
a. A fusible link, but not if the doorset is in an opening provided as a means of escape unless it
complies with paragraph C7.
b. An automatic release mechanism activated by an automatic fire detection and alarm system.
c. A door closer delay device.
Two fire doorsets may be fitted in the same opening if each door is capable of closing the opening,
so the total fire resistance is the sum of their individual resistances. If the opening is provided as a
means of escape, both fire doorsets should be self-closing.
If one fire doorset is capable of being easily opened by hand and has a minimum of 30 minutes’ fire
resistance, the other fire doorset should comply with both of the following.
a. Be fitted with an automatic self-closing device.
b. Be held open by a fusible link.
Fire doorsets often do not provide any significant insulation. Unless providing both integrity
and insulation in accordance with Appendix B, Table B3, a maximum of 25% of the length of a
compartment wall should consist of door openings.
Where it is practicable to maintain a clear space on both sides of the doorway, the above
percentage may be greater.
Rolling shutters should be capable of manual opening and closing for firefighting purposes (see Section 15). Rolling shutters across a means of escape should only be released by a heat sensor, such as a fusible link or electric heat detector, in the immediate vicinity of the door. Unless a shutter is also intended to partially descend as part of a boundary to a smoke reservoir, shutters across a means of escape should not be closed by smoke detectors or a fire alarm system.
The number of occupants of a room, storey, building or part of a building is either of the following.
a. The maximum number of people it is designed to hold.
b. In buildings other than dwellings, the number of people calculated by dividing the area of
a room or storey(s) (m2) by a floor space factor (m2 per person) such as given in Table D1 for
guidance.
Counters and display units should be included when measuring area. All of the following should
be excluded.
a. Stair enclosures.
b. Lifts.
c. Sanitary accommodation.
d. Any other fixed part of the building structure.
Travel distance is measured as the shortest route. Both of the following should be observed.
a. If there is fixed seating or other fixed obstructions, the shortest route is along the centre line of
the seatways and gangways.
b. If the route includes a stair, the shortest route is along the pitch line on the centre line of travel.
Width is measured according to the following.
a. For a door (or doorway), the clear width when the door is open (Diagram D1).
b. For an escape route, either of the following.
i. When the route is defined by walls: the width at 1500mm above finished floor level.
ii. Elsewhere: the minimum width of passage available between any fixed obstructions.
c. For a stair, the clear width between the walls or balustrades. On escape routes and stairs,
handrails and strings intruding into the width by a maximum of 100mm on each side may be
ignored. Rails used for guiding a stair-lift may be ignored, but it should be possible to park the
lift’s chair or carriage in a position that does not obstruct the stair or landing.
The free area of a smoke ventilator should be measured by either of the following.
a. The declared aerodynamic free area in accordance with BS EN 12101-2.
b. The total unobstructed cross-sectional area (geometric free area), measured in the plane where
the area is at a minimum and at right angles to the direction of air flow (Diagram D7).
Sprinkler systems installed in buildings can reduce the risk to life and significantly reduce the
degree of damage caused by fire within a building.
Further recommendations for the provision of sprinklers are provided in the following sections:
Where required, sprinkler systems should be provided throughout the building or separated part,
unless acting as a compensatory feature to address a specific risk. They should be designed and
installed in accordance with the following.
a. For residential buildings, the requirements of BS 9251.
b. For non-residential buildings, or residential buildings outside the scope of BS 9251, the
requirements of BS EN 12845, including the relevant hazard classification together with
additional measures to improve system reliability and availability as described in Annex F of the
standard.
NOTE: Any sprinkler system installed to satisfy the requirements of Part B of the Building
Regulations should be provided with additional measures to improve system reliability and
availability and is therefore to be regarded as a life safety system. However, there may be some
circumstances in which additional measures to improve system reliability and availability specified
in Annex F of BS EN 12845 are inappropriate or unnecessary.
If the provisions in a building vary from those in this document, sprinkler protection can also
sometimes be used as a compensatory feature.
BS 9251 makes additional recommendations when sprinklers are proposed as compensatory features.
For non-residential sprinkler systems designed and installed to BS EN 12845, water supplies should
consist of either of the following.
a. Two single water supplies complying with clause 9.6.1, independent of each other.
b. Two stored water supplies meeting all of the following conditions.
i. Gravity or suction tanks should satisfy all the requirements of clause 9.6.2(b), other than
capacity.
ii. Any pump arrangements should comply with clause 10.2.
iii. In addition to meeting the requirements for inflow, either of the following should apply.
• The capacity of each tank should be at least half the specified minimum water volume
of a single full capacity tank, appropriate to the hazard.
• One tank should be at least equivalent to half the specified water volume of a single
full capacity tank, and the other shall not be less than the minimum volume of a
reduced capacity tank (see clause 9.3.4) appropriate to the hazard.
The total capacity of the water supply in (iii), including any inflow for a reduced capacity
tank, should be at least that of a single full holding capacity tank that complies with
For the systems described in paragraph E5, both of the following apply if pumps are used to draw
water from two tanks.
a. Each pump should be able to draw water from either tank.
b. Any one pump, or either tank, should be able to be isolated.
The sprinkler water supplies should not be used as connections for other services or other fixed
firefighting systems.
F
Other fire-stopping materials include the following. a. Cement mortar. b. Gypsum-based plaster. c. Cement-based or gypsum-based vermiculite/perlite mixes. d. Glass fibre, crushed rock, blast furnace slag or ceramic-based products (with or without resin binders). e. Intumescent mastics. These may be used in situations appropriate to the particular material. Not all materials will be suitable in every situation.