General introduction

  1. Scope
    1. ARRANGEMENT OF SECTIONS
      1. Appendices: provisions common to more than one of Part B’s requirements
        1. Fire performance of materials, products and structures
          1. Fire doors
            1. Methods of measurement
              1. Purpose groups
                1. Definitions
                  1. MANAGEMENT OF PREMISES
                    1. PROPERTY PROTECTION
                      1. INDEPENDENT SCHEMES OF CERTIFICATION AND ACCREDITATION
                        1. SPRINKLER SYSTEMS
                          1. INCLUSIVE DESIGN
                            1. MATERIAL ALTERATION
                              1. ALTERNATIVE APPROACHES
                                1. British Standards
                                  1. Health care premises
                                    1. Unsupervised group homes
                                      1. Shopping complexes
                                        1. Assembly buildings
                                          1. Schools
                                            1. Buildings containing one or more atria
                                              1. Sheltered housing
                                                1. Buildings of special architectural of historic interest

                                                  Scope

                                                  0.1Approved Document B (Fire safety) has been published in two volumes. Volume 1 deals solely with dwellinghouses (see Appendix E and Building Regulation 2(1)), while Volume 2 deals with all other types of building covered by the Building Regulations.

                                                  Where very large (over 18m in height) or unusual dwellinghouses are proposed, some of the guidance in Volume 2 may be needed to supplement that given by Volume 1.

                                                  ARRANGEMENT OF SECTIONS

                                                  0.2 The functional requirements B1 to B5 of Schedule 1 of the Building Regulations are dealt with separately in one or more Sections. The requirement is reproduced at the start of the relevant Sections, followed by an introduction to the subject.

                                                  0.3The provisions set out in this document deal with different aspects of fire safety, with the following aims.

                                                  • B1To ensure satisfactory provision of means of giving an alarm of fire and a satisfactory standard of means of escape for persons in the event of fire in a building.
                                                  • B2To ensure fire spread over the internal linings of buildings is inhibited.
                                                  • B3To ensure the stability of buildings in the event of fire; to ensure that there is a sufficient degree of fire separation within buildings and between adjoining buildings; to provide automatic fire suppression where necessary; and to inhibit the unseen spread of fire and smoke in concealed spaces in buildings.
                                                  • B4To ensure external walls and roofs have adequate resistance to the spread of fire over the external envelope and that spread of fire from one building to another is restricted.
                                                  • B5To ensure satisfactory access for fire appliances to buildings and the provision of facilities in buildings to assist firefighters in the saving of life of people in and around buildings.

                                                  0.4Whilst guidance appropriate to each of these aspects is set out separately in this document, many of the provisions are closely interlinked. For example, there is a close link between the provisions for means of escape (B1) and those for the control of fire growth (B2), fire containment (B3) and facilities for the fire and rescue service (B5). Similarly there are links between B3 and the provisions for controlling external fire spread (B4) and between B3 and B5. Interaction between these different requirements should be recognised where variations in the standard of provision are being considered. A higher standard under one of the requirements may be of benefit in respect of one or more of the other requirements. The guidance in the document as a whole should be considered as a package aimed at achieving an acceptable standard of fire safety.

                                                  0.5In the guidance on B1 the provisions for flats are separated from those for all other types of building because there are important differences in the approach that has been adopted.

                                                  Appendices: provisions common to more than one of Part B’s requirements

                                                  0.6

                                                  • Appendix APerformance of materials, products and structures
                                                  • Appendix BFire doors
                                                  • Appendix CMethods of measurement
                                                  • Appendix DPurpose groups
                                                  • Appendix EDefinitions
                                                  • Appendix FFire behaviour of insulating core panels used for internal structures
                                                  • Appendix GFire safety information
                                                  • Appendix HStandards and other publications referred to.

                                                  Fire performance of materials, products and structures

                                                  0.7 Much of the guidance throughout this document is given in terms of performance in relation to standard fire test methods. Details are drawn together in Appendix A to which reference is made where appropriate. In the case of fire protection systems, reference is made to standards for systems design and installation. Standards referred to are listed in Appendix H.

                                                  Fire doors

                                                  0.8Guidance in respect of fire doors is set out in Appendix B

                                                  Methods of measurement

                                                  0.9Some form of measurement is an integral part of much of the guidance in this document and methods are set out in Appendix C.

                                                  Purpose groups

                                                  0.10Much of the guidance in this document is related to the use of the building. The use classifications are termed purpose groups and they are described in Appendix D.

                                                  Definitions

                                                  0.11The definitions are given in Appendix E. Fire safety Information

                                                  0.12Regulation 16B requires that where building work is carried out which affects fire safety, and where the building affected will be covered by the Regulatory Reform (Fire Safety) Order 2005, the person carrying out the work must provide sufficient information for persons to operate and maintain the building in reasonable safety. This information will assist the eventual owner/ occupier/employer to meet their statutory duties under the Regulatory Reform (Fire Safety) Order.

                                                  The exact amount of information and level of detail necessary will vary depending on the nature and complexity of the building’s design.

                                                  For small buildings, basic information on the location and nature of fire protection measures may be all that is necessary.

                                                  For larger buildings, a more detailed record of the fire safety strategy and procedures for operating and maintaining any fire protection measures of the building will be necessary. Appendix G provides advice on the sort of information that should be provided.

                                                  MANAGEMENT OF PREMISES

                                                  0.13This Approved Document has been written on the assumption that the building concerned will be properly managed.

                                                  Building Regulations do not impose any requirements on the management of a building. However, in developing an appropriate fire safety design for a building it may be necessary to consider the way in which it will be managed. A design which relies 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 any variation in that regime should be the subject of a suitable risk assessment. 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.

                                                  PROPERTY PROTECTION

                                                  0.14There are often many stakeholders, including insurers, who have a valid interest in the fire protection measures which are incorporated into a building’s design. To ensure that the most effective fire protection measures are applied which are appropriate to the specific property, early consultation with the main stakeholders is essential. Failure to consult with stakeholders at an early stage could result in additional measures being required after completion, the use of the building being restricted, or insurance premiums and/or deductibles being increased.

                                                  Building Regulations are intended to ensure that a reasonable standard of life safety is provided, in case of fire. The protection of property, including the building itself, often requires additional measures and insurers will, in general, seek their own higher standards, before accepting the insurance risk.

                                                  Many insurers use the Fire Protection Association’s (FPA) Design Guide for the fire protection of buildings as a basis for providing guidance to the building designer on what they require. Insurers’ key objectives for achieving satisfactory standards of property protection are:

                                                  • ato limit damage to the fabric of the building caused by heat, smoke and firefighting water.
                                                  • b to limit damage to the contents of the building caused by heat, smoke and firefighting water.
                                                  • c to allow the business to be trading in as short a time as possible following a fire, thus limiting business interruption.

                                                  The FPA Design Guide is a suite of publications which incorporate:

                                                  • a An “Essential Principles” document which describes functional requirements.
                                                  • b A range of “Design Principles” documents which provide guidance for common building situations.
                                                  • cSeparate “Core Documents” which expand upon guidance and explain construction detail which will deliver functional requirements.

                                                  Further information can be obtained from the FPA website: www.thefpa.co.uk.

                                                  Guidance on property protection issues for schools is given in Building Bulletin (BB) 100 published by DfES. This gives advice on assessing the financial and social risk of school fires and advocates the use of fire suppression or additional compartmentation where the risk is justified.

                                                  Guidance for asset protection in the Civil and Defence Estates is given in the Crown Fire Standards published by the Property Advisers to the Civil Estate (PACE).

                                                  INDEPENDENT SCHEMES OF CERTIFICATION AND ACCREDITATION

                                                  0.15Since the performance of a system, product, component or structure is dependent upon satisfactory site installation, testing and maintenance, independent schemes of certification and accreditation of installers and maintenance firms of such will provide confidence in the appropriate standard of workmanship being provided.

                                                  Confidence that the required level of performance can be achieved will be demonstrated by the use of a system, material, product or structure which is provided under the arrangements of a product conformity certification scheme and an accreditation of installers scheme.

                                                  Third party accredited product conformity certification schemes not only provide a means of identifying materials and designs of systems, products or structures which have demonstrated that they have the requisite performance in fire, but additionally provide confidence that the systems, materials, products or structures actually supplied are provided to the same specification or design as that tested/assessed.

                                                  Third party accreditation of installers of systems, materials, products or structures provides a means of ensuring that installations have been conducted by knowledgeable contractors to appropriate standards, thereby increasing the reliability of the anticipated performance in fire.

                                                  Building Control Bodies may accept the certification of products, components, materials or structures under such schemes as evidence of compliance with the relevant standard. Similarly, Building Control Bodies may accept the certification of the installation or maintenance of products, components, materials or structures under such schemes as evidence of compliance with the relevant standard. Nonetheless, a Building Control Body will wish to establish, in advance of the work, that any such scheme is adequate for the purposes of the Building Regulations.

                                                  Many certification bodies which approve such schemes are accredited by UKAS.

                                                  SPRINKLER SYSTEMS

                                                  0.16Sprinkler systems installed in buildings can reduce the risk to life and significantly reduce the degree of damage caused by fire. Sprinkler protection can also sometimes be used as a compensatory feature where the provisions of this Approved Document are varied in some way. Where sprinklers are provided, it is normal practice to provide sprinkler protection throughout a building. However, where the sprinklers are being installed as a compensatory feature to address a specific risk or hazard, it may be acceptable to protect only part of a building. Further guidance can also be found in Sprinklers for Safety: Use and Benefits of Incorporating Sprinklers in Buildings and Structures, BAFSA 2006 (ISBN: 0 95526 280 1).

                                                  There are many alternative or innovative fire suppression systems available. Where these are used, it is necessary to ensure that such systems have been designed and tested for use in buildings and are fit for their intended purpose.

                                                  0.17Where a sprinkler system is specifically recommended within this document it should be provided throughout the building or separated part and be designed and installed in accordance with either:

                                                  • afor dwellings and residential buildings, BS 9251:2005 Sprinkler systems for residential and domestic occupancies – Code of practice and BS DD 252 Components for residential sprinkler systems – Specification and test methods for residential sprinklers; or
                                                  • bfor non-residential buildings or dwellings and residential buildings outside the scope of BS 9251, either:
                                                    • ithe requirements of BS 5306-2:1990, including the relevant hazard classification together with the additional requirements for life safety; or
                                                    • iithe requirements of BS EN 12845:2004, including the relevant hazard classification together with the special requirements for life safety systems.

                                                  Notes:Any sprinkler system installed to satisfy the requirements of Part B of the Building Regulations should be regarded as a life safety system. However, there may be some circumstances where a particular life safety requirement, specified in BS 5306-2 or BS EN 12845 is inappropriate or unnecessary.

                                                  0.18Water supplies for non-residential sprinkler systems should consist of either:

                                                  • afor systems designed and installed to BS 5306-2:
                                                    • itwo single water supplies complying with BS 5306-2, clause 13.1.2 where each is independent of the other; or
                                                    • iitwo stored water supplies, where:
                                                      • 1gravity or suction tanks should be either Type A, Type D or their equivalent, (see BS 5306-2 clause 17.4.11.6); and
                                                      • 2any pump arrangements should comply with BS 5306-2 clause 17.4.1.5; and
                                                      • 3the capacity of each tank should be equivalent to at least half the specified minimum water volume of a single full capacity tank, appropriate to the hazard; or
                                                      • 4one tank should be equivalent to half the specified water volume of a single full capacity tank and the other shall not be less than half the minimum volume of a reduced capacity tank (see BS 5306-2, Table 25), appropriate to the hazard; and
                                                        Note: The requirements for inflow should be met.
                                                      • 5whichever water storage arrangement is used at (3) or (4) above, the total design capacity of the water supply, including any inflow for a reduced capacity tank should be at least equivalent to a single full holding capacity tank complying with Table 21, 22, 23 or 24, as appropriate to the hazard and pipework design.
                                                  • bfor systems designed and installed to BS EN 12845:
                                                    • itwo single water supplies complying with BS EN 12845, clause 9.6.1 where each is independent of the other; or
                                                    • iitwo stored water supplies, where:
                                                      • 1gravity or suction tanks should satisfy all the requirements of BS EN 12845 clause 9.6.2 b) other than capacity; and
                                                      • 2any pump arrangements should comply with BS EN 12845 clause 10.2 and
                                                      • 3the capacity of each tank is equivalent to half the specified minimum water volume of a single full capacity tank, appropriate to the hazard; or
                                                      • 4one 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 BS EN12845 clause 9.3.4, appropriate to the hazard; and
                                                        Note: The requirement for inflow should be met.
                                                      • 5 whichever water storage arrangement is used at (3) or (4) above, the total capacity of the water supply, including any inflow for a reduced capacity tank should be at least equivalent to a single full holding capacity tank complying with BS EN12845, Table 9, 10 or clause 9.3.2.3 as appropriate to the hazard and pipework design.

                                                  Where pumps are used to draw water from two tanks, then each pump should be arranged to draw water from either tank and arranged so that any one pump or either tank could be isolated.

                                                  The sprinkler water supplies should generally not be used as connections for other services or other fixed firefighting systems.

                                                  INCLUSIVE DESIGN

                                                  0.19The fire safety aspects of the Building Regulations are made for securing reasonable standards of health and safety of persons in and about buildings. This is intended to include all people, including people with disabilities.

                                                  Part M of the Regulations, Access to and use of buildings, requires reasonable provision for access by people to buildings. Regardless of compliance with Building Regulations, there will also be obligations under the Disability Discrimination Act 1995 for service providers and employers to consider barriers created by physical features in buildings.

                                                  People, regardless of disability, age or gender, should be able to gain access to buildings and use their facilities, both as visitors and as people who live or work in them.

                                                  As such the fire safety measures incorporated into a building will need to take account of the needs of all those persons who may have access to the building. It is not appropriate, except in exceptional circumstances, to presume that certain groups of people will be excluded from a building because of its use.

                                                  The provisions set out in this Approved Document are considered to be a reasonable standard for most buildings. However, there may be some people whose specific needs are not addressed. In some situations additional measures may be needed to accommodate these needs. This should be done on a case by case basis.

                                                  MATERIAL ALTERATION

                                                  0.20Under Regulation 3, the term “material alteration” is defined by reference to a list of “relevant requirements” of Schedule 1 to the Building Regulations. That list includes the requirements of Parts B1, B3, B4 and B5. This means that an alteration which, at any stage of the work, results in a building being less satisfactory than it was before in relation to compliance with the requirements of Parts B1, B3, B4 or B5 is a material alteration, and is therefore controlled by Regulation 4 as it is classed as “building work”. Regulation 4(1) requires that any building work carried out in relation to a material alteration complies with the applicable requirements of Schedule 1 to the Regulations, while Regulation 4(3) requires that once that building work has been completed, the building as a whole must comply with the relevant requirements of Schedule 1 or, where it did not comply before, must be no more unsatisfactory than it was before the work was carried out.

                                                  ALTERNATIVE APPROACHES

                                                  0.21The fire safety requirements of the Building Regulations should be satisfied by following the relevant guidance given in this Approved Document. However, Approved Documents are intended to provide guidance for some of the more common building situations and there may well be alternative ways of achieving compliance with the requirements.

                                                  If other codes or guides are adopted, the relevant recommendations concerning fire safety in the particular publication should be followed, rather than a mixture of the publication and provisions in the relevant sections of this Approved Document. However, there may be circumstances where it is necessary to use one publication to supplement another.

                                                  Guidance documents intended specifically for assessing fire safety in existing buildings will often include provisions which are less onerous than those set out on this Approved Document or other standards applicable to new buildings. As such, these documents are unlikely to be appropriate for use where building work, controlled by the Regulations, is proposed.

                                                  Notes:Buildings for some particular industrial and commercial activities presenting a special fire hazard, e.g. those involved with the sale of fuels, may require additional fire precautions to those detailed in this Approved Document.

                                                  British Standards

                                                  0.21Compliance with a British Standard does not of itself confer immunity from legal obligations. British Standards can, however, provide a useful source of information which could be used to supplement or provide an alternative to the guidance given in this Approved Document.

                                                  When an Approved Document makes reference to a named standard, the relevant version of the standard is the one listed at the end of the publication. However, if this version of the standard has been revised or updated by the issuing standards body, the new version may be used as a source of guidance provided it continues to address the relevant requirements of the Regulations.

                                                  Drafts for Development (DDs) are not British Standards. They are issued in the DD series of publications and are of a provisional nature. They are intended to be applied on a provisional basis so that information and experience of their practical application may be obtained and the document developed. Where the recommendations of a DD are adopted then care should be taken to ensure that the requirements of the Building Regulations are adequately met. Any observations that a user may have in relation to any aspect of a DD should be passed on to BSI.

                                                  Health care premises

                                                  0.23Health care premises are quite diverse and can be used by a variety of patients, often requiring different types of care to suit their specific needs. The choice of fire safety strategy is dependent upon the way a building is designed, furnished, staffed and managed and the level of dependency of the patients.

                                                  In parts of health care premises designed to be used by patients where there are people who are bedridden or who have very restricted mobility, the principle of total evacuation of a building in the event of fire may be inappropriate. It is also unrealistic to suppose that all patients will leave without assistance. In this and other ways the specialised nature of some health care premises demands a different approach to the provision of means of escape, from much of that embodied by the guidance in this Approved Document.

                                                  The Department of Health has prepared a set of guidance documents on fire precautions in health care buildings, under the general title of ‘Firecode’, taking into account the particular characteristics of these buildings. These documents may also be used for non-NHS health care premises.

                                                  The design of fire safety in health care premises is covered by Health Technical Memorandum (HTM) 05-02 Guidance in support of functional provisions for healthcare premises. Part B of the Building Regulations will typically be satisfied where the guidance in that document is followed. Where work to existing healthcare premises is concerned the guidance in the appropriate section of the relevant Firecode should be followed.

                                                  Unsupervised group homes

                                                  0.24 Where an existing house of one or two storeys is to be put to use as an unsupervised group home for not more than six mental health service users, it should be regarded as a Purpose Group 1(c) building if the means of escape are provided in accordance with HTM 88: Guide to fire precautions in NHS housing in the community for mentally handicapped (or mentally ill) people. Where the building is new, it may be more appropriate to regard it as being in Purpose Group 2(b).

                                                  Notes:Firecode contains managerial and other fire safety provisions which are outside the scope of Building Regulations.

                                                  Shopping complexes

                                                  0.25Although the guidance in this Approved Document may be readily applied to individual shops, shopping complexes present a different set of escape problems. The design of units within a shopping complex should be compatible with the fire strategy for the complex as a whole. A suitable approach is given in BS 5588-10:1991.

                                                  Notes:BS 5588-10:1991 applies more restrictive provisions to units with only one exit in covered shopping complexes.

                                                  Assembly buildings

                                                  0.26There are particular problems that arise when people are limited in their ability to escape by fixed seating. This may occur at sports events, theatres, lecture halls and conference centres etc. Guidance on this and other aspects of means of escape in assembly buildings is given in Sections 3 and 5 of BS 5588-6:1991 and the relevant recommendations concerning means of escape in case of fire of that code should be followed in appropriate cases. In the case of buildings to which the Safety of Sports Grounds Act 1975 applies, the Guide to safety at sports grounds TSO (ISBN: 0 11341 001 8) should also be followed.

                                                  Schools

                                                  0.27The design of fire safety in schools is covered by Building Bulletin (BB) 100 published by the DfES. Part B of the Building Regulations will typically be satisfied where the life safety guidance in that document is followed.

                                                  Buildings containing one or more atria

                                                  0.28A building containing an atrium passing through compartment floors may need special fire safety measures. Guidance on suitable fire safety measures in these circumstances is to be found in BS 5588-7:1997 (see also paragraph 8.8). For shopping complexes see paragraph 0.25

                                                  Sheltered housing

                                                  0.29Whilst 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 will depend on the form of the development. For example, a group of specially adapted bungalows or two-storey flats, with few communal facilities, need not be treated differently from other one or two-storey dwellinghouses or flats.

                                                  0.30Fire safety engineering can provide an alternative approach to fire safety. It may be the only practical way to achieve a satisfactory standard of fire safety in some large and complex buildings and in buildings containing different uses, e.g. airport terminals. Fire safety engineering may also be suitable for solving a problem with an aspect of the building design which otherwise follows the provisions in this document.

                                                  0.31British Standard BS 7974 Fire safety engineering in buildings and supporting published documents (PDs) provide a framework and guidance on the design and assessment of fire safety measures in buildings. Following the discipline of BS 7974 should enable designers and Building Control Bodies to be aware of the relevant issues, the need to consider the complete fire-safety system and to follow a disciplined analytical framework.

                                                  0.32Factors that should be taken into account include:

                                                  • athe anticipated probability of a fire occurring;
                                                  • bthe anticipated fire severity;
                                                  • cthe ability of a structure to resist the spread of fire and smoke; and
                                                  • dthe consequential danger to people in and around the building.

                                                  0.33A wide variety of measures could be considered and incorporated to a greater or lesser extent, as appropriate in the circumstances. These include:

                                                  • athe adequacy of means to prevent fire;
                                                  • bearly fire warning by an automatic detection and warning system;
                                                  • cthe standard of means of escape;
                                                  • dprovision of smoke control;
                                                  • econtrol of the rate of growth of a fire;
                                                  • fstructural robustness and the adequacy of the structure to resist the effects of a fire;
                                                  • gthe degree of fire containment;
                                                  • hfire separation between buildings or parts of buildings;
                                                  • ithe standard of active measures for fire extinguishment or control;
                                                  • jfacilities to assist the fire and rescue service;
                                                  • kavailability of powers to require staff training in fire safety and fire routines;
                                                  • lconsideration of the availability of any continuing control under other legislation that could ensure continued maintenance of such systems; and
                                                  • mmanagement.

                                                  0.34It is possible to use quantitative techniques to evaluate risk and hazard. Some factors in the measures listed above can be given numerical values in some circumstances. The assumptions made when quantitative methods are used need careful assessment.

                                                  Buildings of special architectural of historic interest

                                                  0.35Some variation of the provisions set out in this document may also be appropriate where Part B applies to existing buildings, particularly in buildings of special architectural or historic interest, where adherence to the guidance in this document might prove unduly restrictive. In such cases it would be appropriate to take into account a range of fire safety features, some of which are dealt with in this document and some of which are not addressed in any detail and to set these against an assessment of the hazard and risk peculiar to the particular case.