1

This Technical Booklet has been prepared bythe Department of the Environment forNorthern Ireland and provides for certainmethods and standards of building which, iffollowed, will satisfy the requirements of theBuilding Regulations (Northern Ireland) 1994(“the Building Regulations”).

There is no obligation to follow the methods orcomply with the standards set out in thisTechnical Booklet.

If you prefer you may adopt another way ofmeeting the requirements of the BuildingRegulations but you will have to demonstratethat you have satisfied those requirements byother means.

Other regulationsThis Technical Booklet relates only to therequirements of regulations E2, E4, E6, E8 andE10. The work will also have to comply with allother relevant Building Regulations.

British Standards and EuropeanTechnical SpecificationsIn this introduction and throughout thisTechnical Booklet any reference to a BritishStandard shall be construed as a reference to–

(a) a British Standard or British Standard Codeof Practice;

(b) a harmonised standard or other relevantstandard of a national standards body of anyMember State of the European Economic Area;

(c) an international standard recognised foruse in any Member State of the EuropeanEconomic Area;

(d) any appropriate, traditional procedure ofmanufacture of a Member State of theEuropean Economic Area which has atechnical description sufficiently detailed topermit an assessment of the goods or materialsfor the use specified; or

(e) a European Technical Approval issued inaccordance with the Construction ProductsDirective,

provided that the proposed standard, code ofpractice, specification, technical description orEuropean Technical Approval provides, in use,equivalent levels of safety, suitability andfitness for purpose as that provided by theBritish Standard.

Products conforming with a EuropeanCouncil DirectiveAny product designed and manufactured tocomply with the requirements of a EuropeanCouncil Directive does not have to comply withany other standard or part of a standard,whether British, International or other, whichrelates to the same characteristic or specificpurpose as the EC Directive.

EC marked construction productsAny construction product (within the meaning ofthe Construction Products Directive) whichbears an EC Mark shall be treated as if itsatisfied the requirements of any appropriateBritish Board of Agrément Certificate, BritishStandard or British Standard Code of Practicerelating to such a product, where the EC Markrelates to the same characteristic or specificpurpose as the Certificate, Standard or Code ofPractice.

Testing of materials and constructionWhere for the purposes of this TechnicalBooklet testing is carried out it shall be carriedout by an appropriate organisation offeringsuitable and satisfactory evidence of technicaland professional competence andindependence. This condition shall be satisfiedwhere the testing organisation is accredited ina Member State of the European EconomicArea in accordance with the relevant parts ofthe EN 45000 series of standards for the testscarried out.

Introduction

2

Materials and workmanshipAny work to which a requirement of theBuilding Regulations applies must, inaccordance with Part B of the BuildingRegulations, be carried out with suitablematerials and in a workmanlike manner. Youcan comply with the requirements of Part B byfollowing an appropriate British Standard or youmay demonstrate that you have complied withthose requirements by other suitable means,such as an acceptable British Board ofAgrément Certificate, Quality AssuranceScheme, Independent Certification Scheme orAccredited Laboratory Test Certificate.

DiagramsThe diagrams in this Technical Bookletsupplement the text. They do not show all thedetails of construction and are not intended toillustrate compliance with any otherrequirement of the Building Regulations. Theyare not necessarily to scale and should not beused as working details.

ReferencesAny reference in this Technical Booklet to apublication shall, unless otherwise stated, beconstrued as a reference to the edition quoted,together with any amendments, supplements oraddenda thereto current at 28 February 1994.

3

Page

Foreword 4

Section 1 – Means of escape 8

Dwellinghouses 8General provisions 8Roof space conversions 10Automatic fire detection in dwellinghouses 10

Buildings other than dwellinghouses 13Horizontal part of the escape route 13Vertical part of the escape route 22

General provisions 28

Section 2 – Internal fire spread – Linings 32

Classification of performance of materials 32Performance of wall and ceiling linings 33

Section 3 – Internal fire spread – Structure 36

Tests for fire resistance 36Fire resistance of elements of structure and certain

other components of the building 36Compartmentation 43Protected shafts between compartments 46Fire doors 48Provision of cavity barriers 50Pipes penetrating compartment walls, compartment

floors, protected shafts and cavity barriers 56Car parks for light vehicles 60

Section 4 – External fire spread 61

Construction of external walls 61Space separation – External walls 63Canopies 73Roofs 74

Section 5 – Facilities and access for the Fire Brigade 81

Firefighting shafts 81Venting of heat and smoke from basements 83Vehicle access 84

Section 6 – Common provisions 86

Purpose groups 86Rules for measurement 88Non-combustible materials 90Materials of limited combustibility 90Definitions 91

Appendix – Publications referred to 95

Contents

4

0.1 The provisions set out in this TechnicalBooklet under Sections 1 to 5 deal withdifferent aspects of fire safety. Whilst theprovisions appropriate to each of these aspectsare set out separately, many of the provisionsare closely interlinked. For example, there is aclose link between the provisions for means ofescape (Section 1) and those for the control offire growth (Section 2), fire containment(Section 3) and facilities for the Fire Brigade(Section 5). Similarly, there are links betweenSection 3 and the provisions for controllingexternal fire spread (Section 4), and betweenSection 3 and Section 5. Interaction betweenthese different provisions should be recognisedwhen considering alternative solutions as theadoption of a higher standard of provision inrespect of one aspect may be of benefit inrespect to the provisions relating to one ormore other aspects. Thus the provisions in theTechnical Booklet as a whole should beconsidered as a package aimed at achievingan acceptable standard of fire safety.

Provisions common to more than oneSection0.2 Within this Technical Booklet there are anumber of matters which are relevant to morethan one Section. Generally these have beenlocated in the most appropriate Section andcross referenced where necessary. However,the classification of purpose groups, themethods for measurement and definitions areneeded for all Sections and these have beendrawn together for common reference inSection 6.

Section 1 – Means of escape0.3 The provisions in this Section areconcerned with ensuring that occupants aregiven warning of, and have a means of escapefrom, a fire. They only refer to structural fireprecautions where these are necessary tosafeguard an escape route. They have beenprepared on the basis that the occupants ofany part of a building should be able to escapefrom the building, in the event of a fire, without(in most cases) external assistance.

In dwellings and certain other buildings anautomatic fire detection and alarm system cansignificantly increase the level of safety byautomatically giving an early warning of fire. Inother buildings an appropriate fire alarmsystem will provide adequate warning tooccupants.

The design of the means of escape is based onthe assumption that a fire will start in only onelocation and initially be a hazard in that areaonly. Subsequently it may spread to otherparts, usually through circulation routes.Furnishings and equipment are not covered bythe Building Regulations but are usually theitems first ignited in a fire. A fire is less likely tostart within the structure of the building or in acirculation area.

The primary danger in the early stages of a fireis not flame but smoke and other products ofcombustion which can directly affect theoccupants of the building and obscure theescape routes. Measures designed to providesafe means of escape must therefore includeprovisions to limit the spread of smoke andother products of combustion.

The basic principles for the design of means ofescape are –

(a) there shall be alternative means of escapefrom most locations so that people can turntheir back on a fire and travel away from it to aplace of safety; and

(b) where direct escape to a place of safety isnot possible, the aim is to reach a place ofrelative safety, such as a protected stairway,within a reasonable travel distance. In suchcases the escape route will consist of two parts– the first part in unprotected rooms andcirculation areas, and the second part inprotected stairways and in some circumstancesprotected corridors.

A protected stairway is considered to be aplace of relative safety within which people canproceed at their own pace to a place of safety.Smoke and flames must be excluded fromprotected stairways by fire and smoke-resistingconstruction or by an appropriate smokecontrol system or both.

Foreword

5

The following are not acceptable for means ofescape –

(i) a lift (except a suitably designed andinstalled lift for use by disabled people);

(ii) a passenger conveyor or escalator;

(iii) a portable or throw-out ladder; and

(iv) manipulative apparatus and appliances.

Section 2 – Internal fire spread – Linings0.4 The materials used for the linings of wallsand ceilings in a building can significantly affectthe spread of fire and its rate of growth. Theprovisions in Section 2 restrict the spread offire over internal linings by ensuring they havelow rates of surface spread of flame. In somelocations the internal linings must also have alow rate of heat production so as to limit thecontribution that the fabric of the buildingmakes to fire growth.

There are no provisions in relation to the uppersurfaces of floors and stairs because suchsurfaces are not involved significantly in a fireuntil it is well developed. They do not thereforeplay an important part in fire spread during theearly stages of a fire, which are the mostrelevant to the life safety of occupants.

Although furniture and fittings can have a majoreffect on fire spread it is not possible to controlthem through Building Regulations, and noprovisions relating to them are included in thisTechnical Booklet. The fire characteristics offurniture and fittings may be controlled in somebuildings under other legislation which appliesto those buildings when in use.

Section 3 – Internal fire spread –Structure0.5 The spread of fire within a building can berestricted by the provision of structuralmeasures such as fire-resisting elements ofconstruction, compartmentation, cavity barriersand fire-stopping.

Fire-resisting elements of construction – theobjective of providing the elements of structureand certain other components of the buildingwith a minimum standard of fire resistance is tominimise the risk to the occupants whilstevacuating, to the firefighting personnel whilstengaged in search and rescue operations andto people in the vicinity of the building who maybe hurt by falling debris or as a result of theimpact of the collapsing building on anotherbuilding.

Compartmentation – the spread of fire within abuilding can be restricted by subdividing it intocompartments separated from one another bywalls and/or floors of fire-resisting construction.The objectives are to prevent rapid fire spread,which could trap occupants of the building, andto reduce the chance of a fire becoming large,on the basis that a large fire is moredangerous, not only to occupants and fire-fighting personnel, but to people in the vicinityof the building.

Cavity barriers – concealed and extensivespaces within construction provide a readyroute for the hidden spread of smoke andflame. The objectives of cavity barriers are tolimit the extent of such spaces and to subdividethem where they would otherwise form apathway around fire-resisting construction.

Protection of penetrations – in order that thefire integrity of elements of structure intendedto provide fire separation is maintained,penetrations of such construction, by pipes,ducts, cables, etc. must be suitably protected.

Fire-stopping – the objective of fire-stopping isto adequately seal or protect every joint,imperfection of fit, opening and penetration inan element of structure intended to provide fireseparation, so that its effectiveness is notimpaired.

This Section also contains provisions relating tocar parks for light vehicles. In buildings orseparated parts of buildings used as parking forcars and other light vehicles the fire load is welldefined and not particularly high. Fire spread isnot likely to occur between one vehicle andanother and, where the car park is wellventilated (so that heat and smoke candissipate readily) there is a low probability offire spread from one storey to another.

Section 4 – External fire spread0.6 The extent to which fire will spread overand between buildings depends on the sizeand intensity of the fire, the construction of theexternal walls and roof, and the distancebetween the buildings.

Construction of walls – the fire resistance of anexternal wall and the combustibility of itsexternal face are controlled to reduce itssusceptibility to ignition from an external sourceand the danger from fire spreading up theexternal face of the building.

6

Construction of roofs – the combustibility of theexternal surface of a roof is controlled toreduce its susceptibility to ignition from anexternal source.

Distance between buildings – adequateseparation between buildings is achieved byrelating the amount of unprotected area (e.g.windows, areas of combustible wall, etc.) in thewall of a building or compartment to thedistance that wall is from its relevant boundary.It may be advantageous to reducecompartment sizes or to providecompartmentation where none would otherwisebe necessary, as this will reduce the size of thefire and may permit a reduced boundarydistance or alternatively, an increase inunprotected area.

Section 5 – Facilities and access for theFire Brigade0.7 The provisions relating to facilities andaccess are for the purposes of assisting theFire Brigade to ensure the safety of people inand around a building.

Generally in small buildings the combination ofthe access offered by the normal means ofaccess and egress, and the ability of the fireBrigade to work from ladders and appliancesare sufficient without special access or internalfacilities. However, in large buildings andbuildings with basements the Fire Brigade willinvariably work inside the building andfirefighting shafts, fire mains, venting ofbasements and access will be necessary.

Firefighting shafts – the provisions are toensure that the Fire Brigade will have a secureoperating base on every storey of largebuildings.

Fire mains – the purpose of a fire main within afirefighting shaft is to enable firefighters toconnect hoses and receive a supply of waterfor firefighting and rescue activities.

Access – the provisions relating to vehicleaccess are to enable the Fire Brigade’spumping appliances to supply water to the firemains and for high reach appliances to bedeployed.

Venting of basements – the enclosed nature ofa basement prevents the dispersal of heat andsmoke, which tend to rise up the access thatthe Fire Brigade may be using to approach thefire. The provisions for smoke removal facilitiesare to enable firefighters to more effectivelysearch for and rescue any people who may betrapped, and to locate and attack the fire.

Fire safety engineering0.8 A fire safety engineering approach whichtakes into account the total fire safety packagewithin a building may provide an adequate levelof fire safety. Indeed, it may be the only viableapproach to the achievement of a satisfactorystandard in some large and complex buildingsbut it is beyond the scope of this TechnicalBooklet.

Fire safety for disabled people0.9 Deemed to satisfy provisions for means ofescape for disabled people are contained in BS5588: Part 8: 1988. However, incorporatingspecial structural measures to aid means ofescape for disabled people may not be neededwhere it can be shown that adequatemanagement arrangements to provide assistedescape will be available.

Other legislation0.10 The provisions of this Technical Bookletrelate to the requirements of the BuildingRegulations and do not include measureswhich may be necessary to meet therequirements of other legislation. Such otherlegislation generally operates when a buildingis brought into use and extends to coveraspects which are outside the scope of theBuilding Regulations.

The main legislation in this area is the FireServices (Northern Ireland) Order 1984 whichprovides for the designation of certain uses ofpremises and is enforced by the Fire Authority.Under that Order designated premises must beprovided with means of escape in case of fireand those premises over certain limits musthave their means of escape certified.

7

The Fire Authority cannot require structural orother alterations as a condition of issuing a firecertificate where plans were, in accordancewith the Building Regulations, deposited withthe District Council. However, where the FireAuthority is satisfied that the means of escapeare inadequate by reason of matters orcircumstances, particulars of which were notrequired to be supplied to the District Council inconnection with the deposit of plans forBuilding Regulations purposes, then the FireAuthority is not barred from requiring suchalterations.

Other legislation, such as that for entertainmentlicensing, is enforced by the District Counciland does not contain a similar bar to that in theFire Services Order.

Property protection0.11 Building Regulations are intended toensure that an adequate standard of life safetyis provided in case of fire. The protection ofproperty, including the building itself, mayrequire additional measures and insurers will ingeneral seek their own measures if they are toaccept the insurance risk. Such measures (e.g.locking doors on escape routes) must notnegate or reduce the level of protection orperformance of any provision in this TechnicalBooklet.

8

1.1 The provisions in this Section have beenformulated using assumptions regarding thelikely source and growth of a fire and are basedon recognised criteria for means of escape.These assumptions and criteria are outlined inthe Foreword – see paragraph 0.3.

The provisions are divided into –

(a) those applying to dwellinghouses –paragraphs 1.2 and 1.23;

(b) those applying to all types of buildingsother than dwellinghouses –

(i) the horizontal part of the escape route– paragraphs 1.26 to 1.42; and

(ii) the vertical part of the escape route –paragraphs 1.43 to 1.58; and

(c) general provisions applying todwellinghouses and all other types of buildings– paragraphs 1.59 to 1.75.

Dwellinghouses

Introduction1.2 The provisions for means of escape intypical one and two storey dwellinghouses (i.e.those with no storey more than 4.5 m aboveground level) are limited to those given inparagraphs 1.3 to 1.6.

With increasing height additional provisions arenecessary as stairs may become impassablebefore evacuation is complete. The additionalprovisions are given in paragraphs 1.7 to 1.10.

Where an external escape route is provided theprovisions contained in paragraphs 1.41, 1.42and 1.58 shall also apply.

General provisions1.3 Every storey (including a basement storey)in a dwellinghouse which does not havealternative escape routes leading to their ownexits shall have an openable window,complying with paragraph 1.6, for escape orrescue purposes.

1.4 A habitable room shall open directly onto ahallway (including a corridor or landing leadingto the hallway) which leads to the entrancewithout passing through any room (except aporch), other than where the habitable room –

(a) has an alternative escape route;

(b) is on a storey not more than 4.5 m aboveground level and the habitable room has anopenable window complying with paragraph1.6; or

(c) is part of a roof space conversion whichcomplies with paragraphs 1.11 to 1.16.

Access rooms to inner rooms1.5 A habitable room may be an access roomto any inner room. A kitchen shall not be anaccess room to an inner room other than –

(a) to a utility room or conservatory which hasan openable window complying with paragraph1.6; or

(b) where the kitchen is part of an alternativeescape route.

Openable windows for escape or rescue1.6 An openable window for escape or rescuepurposes shall –

(a) have a clear opening that is at least 850mm high and 500 mm wide. The lower edge ofthe window opening shall be not less than 800mm and not more than 1100 mm above thefloor except in the case of a roof window wherethe lower edge of the window opening may benot less than 600 mm above the floor;

(b) where practicable – be located remote fromthe primary escape route; and

(c) not lead to an enclosed yard or gardenunless it has an area of relative safety which isnot less than the height of the dwellinghousefrom the dwellinghouse. An enclosed yard orgarden is one from which there is no exit underthe control of the occupants of thedwellinghouse.

Where the openable window is from an upperstorey that window shall be located to facilitaterescue by ladder from the ground.

Where the openable window is a dormer orroof window it shall be positioned as shown onDiagram 1.1.

For the purposes of this paragraph anopenable window shall be taken to include adoor which leads to an area (e.g. a balcony)from which a person could be rescued. Theminimum height to the lower edge of theopening, given in sub-paragraph (a), shall notapply to such a door.

Section 1 – Means of escape

9

Additional provisions for adwellinghouse with one storey morethan 4.5 m above ground level1.7 In a dwellinghouse with only one storeymore than 4.5 m above ground level –

(a) the top storey shall –

(i) be separated from the lower storeys byfire-resisting construction; and

(ii) have an alternative escape routeleading to its own final exit; or

(b) all storeys above the storey containing thefinal exit shall be served by a protectedstairway which either –

(i) extends to a final exit as shown inDiagram 1.2(a); or

(ii) leads to at least two escape routes atground level, each leading to a final exitand separated from each other by fire-resisting construction and self-closing firedoors as shown in Diagram 1.2(b).

1.8 Where the storey which is more than 4.5 mabove ground level is created by theconversion of the roof space of a one or twostorey dwellinghouse the provisions ofparagraphs 1.11 to 1.16 may be applied as analternative to the provisions of paragraph 1.7.

Additional provisions for adwellinghouse with two or more storeysmore than 4.5 m above ground level1.9 In a dwellinghouse with two or morestoreys more than 4.5 m above ground level –

(a) all storeys above the storey containing thefinal exit shall be served by a protectedstairway which complies with paragraph 1.7(b);and

(b) each storey that is over 7.5 m aboveground level shall have an alternative escaperoute leading to its own final exit. Whereaccess to an alternative escape route isthrough the protected stairway, the protectedstairway shall be subdivided by fire-resistingconstruction at or about 7.5 m above groundlevel.

bottom of opening

800–1100mm

floor level

eaves

1.7m

max

.

1.7m

max

.

eaves

bottom of opening

600–1100mm

floor level

(a) Dormer window

Note

Clear window opening at least 850mm high by 500mm wide.The window may be in the end wall of the dwellinghouse instead of the roof as shown.

(b) Roof window (rooflight)

Diagram 1.1 Escape windows from roof space conversions

see para 1.6 and 1.16(b)

10

Ducted warm air heating systems1.10 In a dwellinghouse with a storey morethan 4.5 m above ground level, any system ofducted warm air heating shall –

(a) not be fitted with transfer grilles betweenany room and a protected stairway;

(b) not have supply and return grilles morethan 450 mm above floor level;

(c) where warm air is ducted to a protectedstairway – have the return air ducted back tothe heater;

(d) where a duct passes through the enclosureto a protected stairway – have the jointsbetween the duct and the enclosure firestopped; and

(e) have a thermal cut out with maximumsetting of 35°C, which turns off the heater andany circulation fan if the ambient temperatureexceeds that setting.

Roof space conversions1.11 Where a roof space is to be converted tohabitable accommodation either –

(a) the relevant provisions of paragraphs 1.3 to1.10 shall apply; or

(b) where the existing dwellinghouse has twostoreys the provisions in paragraphs 1.12 to1.16 may be followed provided that the newstorey does not –

(i) exceed 50 m2 in area; or

(ii) contain more than two habitablerooms.

Enclosure of existing stairway1.12 The existing stairway shall be enclosedby fire-resisting walls and either –

(a) extend to a final exit as shown in Diagram1.2(a); or

(b) lead to at least two escape routes atground level, each delivering to a final exit andseparated from each other by fire-resistingconstruction and self-closing fire doors asshown in Diagram 1.2(b).

1.13 Any glazing in the enclosure of theexisting stairway, other than to a bathroom orsanitary accommodation, shall be fire-resisting.

1.14 Other than where paragraph 1.12 requiresa fire door, every doorway in the enclosure tothe existing stairway shall be fitted with animperforate door. A door to a habitable roomshall be fitted with a self-closing device.

Where a new door is to be provided to anexisting habitable room it shall be a fire door.

Fire separation of new storey1.15 The new storey shall be separated fromthe rest of the dwellinghouse by fire-resistingconstruction. The new stairway shall either –

(a) rise as a continuation of the existingstairway and enclosure, in which case thestairway shall be separated from the newaccommodation by fire-resisting construction;or

(b) be separated from the existing stairwayand the rest of the dwellinghouse by fire-resisting construction.

Any door in new fire-resisting construction shallbe a self-closing fire door.

1.16 Each habitable room in the new storeyshall have –

(a) an openable window which complies withparagraph 1.6; or

(b) an openable dormer window or roofwindow, of the size given in paragraph 1.6located as shown in Diagram 1.1.

Automatic fire detection indwellinghouses1.17 A dwellinghouse shall be provided witheither –

(a) a self-contained smoke alarm or alarmscomplying with BS 5446: Part 1: 1990 installedin accordance with paragraphs 1.18 to 1.23; or

(b) an automatic fire detection and alarmsystem complying with BS 5839: Part 1: 1988of at least L3 standard.

However, in a very large dwellinghouse (wherethe shortest route from any point in one roomto the furthest point in any other room on thesame storey is more than 30m) self-containedsmoke alarms are not adequate and anautomatic fire detection and alarm system shallbe fitted.

11

Provision of self-contained smokealarms1.18 At least one self-contained smoke alarmshall be provided on each storey and the alarmor alarms shall be located to comply with theprovisions of paragraphs 1.20 to 1.22.

Where a dwellinghouse has more than oneself-contained smoke alarm the alarms shall beinterconnected so that they all give an audiblealarm when any one of them detects smoke.

The maximum number of self-contained smokealarms which may be interconnected shall notexceed that given in the manufacturer’sinstructions.

Installation of self-contained smokealarms

1.19 Self-contained smoke alarms shall bepermanently wired to a circuit which –

(a) is separately fused at the distribution board;

(b) serves only self-contained smoke alarms;and

(c) where a residual current device is used – isnot connected to a residual current devicewhich is also used by any other circuit.

Self-contained smoke alarms may operate at alow voltage via a mains transformer. The cablefor the power supply to, and interconnection of,the smoke alarms need not have special fire-survival properties.

Diagram 1.2 Alternative arrangements for final exits

see para 1.7(b) and 1.12(a) & (b)

F.D.

F.D.

F.D.

F.D.

protectedstairway

protectedstairway

final exitfinal exit

final exit

F.D.

Key

fire-resisting door

fire-resisting construction

(a) Protected stairway deliveringdirectly to the final exit

(b) Protected stairway affording accessto two independent escape routes

F.D.

F.D.

12

1.20 Self-contained smoke alarms shall belocated in the circulation route or routes of adwellinghouse so that there is one –

(a) not more than 3 m from every bedroomdoor;

(b) not more than 7 m from every door to aliving room or kitchen; and

(c) where a circulation route on a storey ismore than 15 m long – not more than 15 mfrom another self-contained smoke alarm onthe same circulation route and storey.

1.21 A self-contained smoke alarm shall belocated so that it is –

(a) either on a ceiling and not less than 300mm from a wall or light fitting, or wheredesigned for wall mounting on a wall and notless than 150 mm, or more than 300 mm fromthe ceiling;

(b) not less than 300 mm from, and not directlyabove, a heater or an air conditioningventilator;

(c) on a surface which is normally at theambient temperature for the space it bounds;and

(d) easily and safely accessible.

1.22 A self-contained smoke alarm shall not belocated in a kitchen, garage or other placewhere steam, condensation or fumes couldgive false alarms.

1.23 Where dwellinghouses are part of asheltered dwelling scheme with a warden orsupervisor, a self-contained smoke alarm withineach dwellinghouse shall be connected to thewarden’s or supervisor’s central monitoringpoint so as to –

(a) give an audible warning of the detection ofsmoke in any dwellinghouse; and

(b) enable the identification of thedwellinghouse involved.

13

Buildings other thandwellinghouses

1.24 In buildings other than dwellinghouses thenumber of escape routes needed depends onthe number of occupants (occupant capacity).In some cases a room or a storey is designedto accommodate a known number of people; inothers the occupant capacity shall becalculated by dividing the area of the room orstorey (excluding stairways, lifts and sanitaryaccommodation) by the appropriate floor spacefactor given in Table 1.1. Where the occupantcapacity is calculated for rooms the occupantcapacity of a storey is the sum of the occupantcapacities of the rooms on that storey. Theoccupant capacity of a building or part of abuilding is the sum of the occupant capacitiesof the storeys in that building or part.

1.25 Where a building contains areas indifferent purpose groups the means of escapefrom any area which is of Purpose Group 1(a),2 or 5 shall be independent of the means ofescape from other areas of the building.

Horizontal part of the escape route1.26 The provisions in paragraphs 1.27 to 1.42relate to horizontal escape routes leading tostorey exits. They are mainly concerned withproviding more than one escape route (exceptin the circumstances described in paragraph1.27), limiting the distance to be travelled, andensuring that the routes are of adequate width.

Single escape routes1.27 Alternative escape routes shall beprovided from all parts of the building otherthan in the following circumstances where asingle route is permitted –

(a) areas from which a storey exit can bereached within the maximum travel distance inone direction only given in Table 1.2, providedthat no room in this situation has an occupantcapacity of more than 50 people, or 30 peopleif the building is an Institution [Purpose Group2(a)]; and

(b) a storey with an occupant capacity of nomore than 50 people, provided that a storeyexit can be reached within the maximum traveldistance in one direction only given inTable 1.2.

Travel distance1.28 Whether there are alternative escaperoutes or only a single one, the travel distanceto the nearest storey exit shall not exceed themaximum relevant travel distance given inTable 1.2.

Where the initial part of an escape route is inone direction only (e.g. as shown in Diagram1.3 where there is one escape route from aroom to a corridor, from which point escape ispossible in two directions), that part shall notexceed the maximum travel distance in onedirection only, and the overall travel distanceshall not exceed the maximum travel distancein more than one direction.

Number of escape routes and exits1.29 The number of escape routes and exitsshall not be less than the number given inTable 1.3 for the relevant occupant capacity ofthe room or storey as appropriate. The escaperoutes and exits shall be arranged such thatthe travel distances given in Table 1.2 are notexceeded.

14

Table 1.1 Floor space factors

Floor spaceItem Type of accommodation (1)(2) factor

m2/person

1 Standing spectator areas 0.3

2 Amusement arcade, assembly hall (including a general 0.5purpose place of assembly) bar (including a lounge bar), bingo hall, dance flooror hall, club, crush hall, venue for pop concert and similar events, queuing area

3 Concourse (other than in a shopping complex)(3) 0.75

4 Committee room, common room, conference room, dining 1.0(4)

room, licensed betting office (public area), lounge (other than lounge bar),meeting room, reading room, restaurant, staff room, waiting room

5 Exhibition hall 1.5

6 Shop sales area(5), skating rink 2.0

7 Art gallery, dormitory, factory production area, 5.0office (open-plan exceeding 60 m2), workshop

8 Kitchen, library, office (other than in 7 above), shop 7.0sales area(6)

9 Bedroom or study-bedroom 8.0

10 Bed-sitting room, billiards room 10.0

11 Storage and warehouse accommodation 30.0

12 Car park Two peopleper parking

space

Notes –

(1) Where accommodation is not directly covered by the descriptions given, a reasonable value based on a similar usemay be selected.

(2) If there is to be mixed use, the most onerous factor should be applied.

(3) The deemed-to-satisfy provision given in regulation E3 (i) for shopping complexes is BS 5588: Part 10: 1991.

(4) Alternatively, the occupant capacity may be taken as the number of fixed seats provided, if the occupants willnormally be seated.

(5) Shops, other than those included under item 8, including – supermarkets and department stores (all sales areas),shops for personal services such as hairdressing and shops for the delivery or collection of goods for cleaning,repair or other treatment or for members of the public themselves carrying out such cleaning, repair or othertreatment.

(6) Shops, excluding those in covered shopping complexes and department stores, trading predominantly in furniture,floor coverings, cycles, perambulators, large domestic appliances or other bulky goods, or trading on a wholesaleself-selection basis (cash and carry).

15

Table 1.2 Limitations on travel distances

Maximum travel distance(1)

where travel is possible in –Purpose Use of the building

group or part of the buildingOne direction More than one

only (m) direction (m)

2(a) Institutional 9 18

2(b) Other residential –

(a) in bedrooms 9(2) 18(2)

(b) in bedroom corridors 9 35(c) elsewhere 18 35

3 Office 18 45

4 Shop and commercial 18 45

5 Assembly and recreation –

(a) buildings primarily for thehandicapped (except schools) 9 18

(b) elsewhere 15 32

6 Industrial(3) 25 45

7 Storage and other non-residential(3) 18 45

2, 3, 4, Place of special fire risk(4) 9(2) 18(2)

5, 6and 7

2, 3, 4, Plant room or rooftop plant –5, 6and 7 (a) distance within the room 9 35

(b) escape route not in open air 18 45(overall travel distance)

(c) escape route in open air 60 100(overall travel distance)

Notes –

(1) The dimensions in the Table are travel distances. If the internal layout of partitions, fittings, etc. is not known whenplans are deposited, direct distances may be used for assessment. The direct distance shall be taken as two-thirdsof the travel distance.

(2) Maximum part of travel distance within the room.

(3) In industrial buildings the appropriate travel distance depends on the level of fire risk associated with the processesand materials being used.

The dimensions given above assume that the building will be of normal fire risk. If the building is high risk, thenlesser distances of 12 m in one direction and 25 m in more than one direction, shall apply.

(4) Places of special fire risk are listed in the definitions in paragraph 6.6.

16

Table 1.3 Number of escape routesand exits

Maximum Minimum number ofoccupant escapecapacity routes/exits

500 2(1)

1000 3

2000 4

4000 5

7000 6

11000 7

16000 8

More than 16000 8(2)

Notes –

(1) See paragraph 1.27 for the circumstances in whichsingle exits and escape routes are acceptable.

(2) Plus 1 per 5000 people (or part thereof) over 16000.

Alternative escape routes1.30 To prevent alternative escape routesbeing simultaneously unusable they shalleither –

(a) be 45° or more apart (see Diagram 1.4); or

(b) if less than 45° apart be separated fromeach other by fire-resisting construction.

Inner rooms1.31 An inner room is only permitted where –

(a) the number of occupants of the inner roomis not more than 50 people (or in the case of abuilding in Purpose Group 2(a), 30 people);

(b) is not a bedroom;

(c) the escape route from the inner room doesnot pass through more than one access room;

(d) the distance from any point in the innerroom to the nearest exit from the access roomdoes not exceed the appropriate maximumtravel distance in one direction only given inTable 1.2;

(e) the access room is not a place of specialfire risk and is in the control of the sameoccupier as the inner room; and

(f) one of the following applies –

(i) that part of the enclosure separatingthe inner and access room is stopped atleast 500 mm below the ceiling;

(ii) a vision panel of not less than 0.1 m2

is provided in the enclosure to the innerroom so that a fire in the access room willbe visible from the inner room at an earlystage; or

(iii) the access room is fitted with asuitable automatic detection and alarmsystem to warn the occupants of the innerroom of the outbreak of a fire in theaccess room.

17

see para 1.28

Diagram 1.3 Travel distance in single direction leading to alternativeescape routes

If angle CBD is 45� or more alternative escape routes are available from B provided either AC or AD is less than or equal to the maximum travel distance in more than one direction and AB is less than or equal to the maximum travel distance in one direction only.

C

B

45� or more

A

D

Diagram 1.4 Alternative escape routes

see para 1.30(a)

C

B

45� or more

AD

less than 45�

Acceptable alternative escape routes are available from A (so that either AB or AC is less than or equal to the maximum travel distance in more than one direction) but not from D.

18

Access to storey exits1.32 In any storey which has more than oneescape stairway the escape routes shall bearranged so that people do not have to passthrough one stairway to reach another.However, it is acceptable to pass through theprotected lobby of one stairway to reachanother escape stairway.

Separation of circulation routes fromescape stairways1.33 A protected stairway shall not form part ofthe primary circulation route between differentparts of the building at the same level.However, it is acceptable for a protected lobbyto form part of the primary circulation route.

Open spacial planning1.34 Escape routes shall not be prejudiced byopen connections between floors such as at anescalator.

An escape route shall not be within 5 m of theopen connection unless –

(a) the direction of travel is away from theopening; or

(b) there is an alternative escape route whichdoes not pass within 5 m of the openconnection.

See Diagram 1.5.

Planning of storey exits in a central core1.35 A building with more than one storey exitin a central core shall be planned so that thestorey exits are remote from each other andnot linked by a lift hall, lobby, or undividedcorridor.

Where the central core is separated from theaccommodation by a corridor, the corridor shallbe subdivided by self-closing fire doors (andany necessary associated screens) so that thestorey exits are separated as in Diagram 1.6.

Storeys divided into differentoccupancies1.36 Where a storey is divided into two ormore occupancies (i.e. ownerships, tenanciesor similar) the means of escape from oneoccupancy shall not pass through any otheroccupancy.

However, where the means of escape includesa corridor common to two or more occupanciesthen either it shall be a protected corridor, or afire detection and alarm system to BS 5839:Part 1: 1988, of at least L3 standard, shall beinstalled.

Width of escape routes and storey exits1.37 The width of an escape route or storeyexit shall be not less than the minimum width,given in Table 1.4, for the appropriate numberof people assessed as being likely to use it.There shall be no projections into escaperoutes and storey exits other than door framesand handrails with a projection of less than 100mm. (Note – for the purposes of Part H stairwidths are measured between handrails.)

Where there is a single escape route andstorey exit their capacity shall be not less thanthe number of occupants of the storey.

Where two or more escape routes and storeyexits are provided it shall be assumed that oneof them may not be available due to fire orsmoke. Therefore, each storey exit in turn shallbe discounted in order to ensure that thecapacity of the remaining storey exits isadequate for the total number of peopleneeding to use them.

Table 1.4 Widths of escape routesand storey exits

Maximum number Minimum widthof people(1) mm

50 800(2)

110 900

220 1100

More than 220 5 per person

Notes –

(1) Assessed as being likely to use the escape route orstorey exit.

(2) May be reduced to 530 mm for gangways betweenfixed storage racking, other than in public areas inPurpose Group 4 buildings.

19

see para 1.34

Diagram 1.5 Escape routes in relation to open connectionsbetween floors

From A and B at least one direction of travel is away from the opening. From C where the initial direction of travel is towards the opening one of the escape routes is not less than 5mfrom the opening.

C

B

Aopening

exit

exit

exit

5m

Diagram 1.6 Storey exits in a central core

see para 1.35

lift

lift

lift

lift

lift

lift

corridor

corridor

toiletswashroom

servicesetc

F.D. F.D.

accommodation

accommodation

alternative position forfire-resisting doorshown dashed

alternative position forfire-resisting doorshown dashed

Key

F.D.

fire-resisting door

fire-resistingconstruction

20

Protected corridors1.38 A corridor that is part of the means ofescape shall be a protected corridor where itis –

(a) within residential accommodation;

(b) a corridor from which escape is in onedirection only (i.e. a dead end corridor); or

(c) common to two or more differentoccupancies other than where a fire detectionand alarm system is installed in accordancewith paragraph 1.36.

Subdivision of corridors1.39 Where a corridor exceeding 12 m inlength connects two or more storey exits, itshall be subdivided by self-closing fire doors(and any necessary associated fire-resistingscreens) so that no undivided part is commonto two or more storey exits. For corridorsaround a central core see paragraph 1.35.

Where a dead end portion of a corridorexceeding 4.5 m in length leads to a pointwhere alternative escape routes are available,the dead end portion shall be extended andseparated by self-closing fire doors (and anynecessary associated fire-resisting screens)from the remainder of the corridor as shown inDiagram 1.7. However, where the stairwaysand corridors are protected by a pressurizationsystem complying with BS 5588: Part 4: 1978,such separation is not necessary.

Enclosure of corridors that are notprotected corridors1.40 Where a corridor which is part of anescape route, but is not a protected corridor, isenclosed by partitions, those partitions shall becarried up to the underside of the structuralfloor or to a suspended ceiling. In the lattercase cavity barriers shall be provided inaccordance with paragraph 3.27. Everyopening into a room shall be fitted with a door.

External escape routes1.41 Where an external escape route, otherthan a stair, is beside an external wall of thebuilding, that part of the external wall within 3 m(measured horizontally) of the escape routeshall be of fire-resisting construction 1.8 mabove and 9 m below the level of the route asshown in Diagram 1.9 (see page 27).

Escape over flat roofs1.42 Where more than one escape route isavailable from a storey, (or part of a buildingwhere appropriate) one of those routes may beby way of a flat roof, provided that –

(a) the route does not serve –

(i) a building of Purpose Group 2(a); or

(ii) in a building of any other purposegroup – an area intended for use bymembers of the public;

(b) the flat roof is part of the same buildingfrom which escape is being made;

(c) the route across the flat roof leads to anescape stair;

(d) the part of the flat roof forming the escaperoute and its supporting structure, together withany opening in the roof within 3 m of theescape route, is fire-resisting; and

(e) the route is defined and guarded by wallsand/or protective barriers which comply withPart H.

21

Diagram 1.7 Dead-end corridors

see para 1.39

F.D. F.D.

F.D.

F.D.

F.D. F.D.

F.D. F.D. F.D.

F.D.

F.D. F.D.

F.D. F.D.

F.D.

F.D. F.D.

F.D.

Key

fire-resisting door

fire-resisting construction

protected corridor

(a) T–junction with main corridor

(b) Continuation past stairway

22

Vertical part of the escape route1.43 The provisions in paragraphs 1.44 to 1.58relate to the vertical escape down or up escapestairways towards a final exit. They are mainlyconcerned with providing a sufficient number ofescape stairs of adequate aggregate width andtheir protection.

Number of escape stairways1.44 The number of escape stairways in abuilding, or part of a building is determined bythe provisions in –

(a) paragraph 1.25 regarding independentescape routes from areas in certain uses;

(b) paragraphs 1.27 and 1.29 regarding thedesign of the horizontal part of the escaperoute;

(c) paragraphs 1.46 and 1.47 regarding thewidth of stairs and the discounting of a stairwayrespectively; and

(d) Section 5 regarding the provision andlocation of firefighting stairways.

Single escape stairways1.45 Where independent escape routes are notrequired from areas in different purposegroups, in accordance with paragraph 1.25, asingle escape stairway may serve –

(a) a basement which is permitted to have asingle escape route in accordance withparagraph 1.27; or

(b) a building which has no storey with a floorlevel more than 10 m above ground level, andin which every storey is permitted to have asingle escape route in accordance withparagraph 1.27.

Width of escape stairs1.46 an escape stair shall be wide enough toaccommodate the appropriate number ofpeople assessed as being likely to use it.

This width will depend on the number ofstairways provided and whether the escapestrategy is based on the total evacuation (seeparagraph 1.48) or phased evacuation (seeparagraph 1.49).

In any event an escape stair shall –

(a) be not less than the appropriate dimensiongiven in Table 1.5;

(b) be not less than the width required for anystorey exit giving access to it;

(c) not reduce in width at any point on its wayto the final exit; and

(d) not exceed 1400 mm if the vertical extentof the escape stair is more than 30 m, unless itis at least 1800 mm and it is provided with acentral handrail. In such a case the width oneach side of the handrail shall be consideredseparately for the purpose of assessing staircapacity.

Discounting of escape stairways1.47 Whether total or phased evacuation isused, where two or more escape stairways areprovided it shall be assumed that one of themmay not be available due to fire or smoke.Therefore, each stairway in turn shall bediscounted in order to ensure that the capacityof the remaining stairways is adequate for thetotal number of people needing to use them.

This discounting provision need not be appliedwhere –

(a) the escape stairways are approached oneach storey (except the topmost storey),through a protected lobby; or

(b) the escape stairways are protected bypressurization systems designed in accordancewith BS 5588: Part 4: 1978.

Total evacuation1.48 In a building or part of a building designedfor total evacuation the escape stairways shallhave the capacity to allow all floors to beevacuated simultaneously and a suitable firealarm system to BS 5839: Part 1: 1988, shallbe installed.

Total evacuation shall be used for –

(a) a basement;

(b) a building containing open spacial planning;

(c) a building of Purpose Group 2; and

(d) a building of Purpose Group 5.

23

Where total evacuation is to be used thecapacity of an escape stairway shall be either –

(i) in a building of not more than 10 storeysand for basements – that given for theappropriate width of escape stairs in Table 1.6;or

(ii) in a building of more than 10 storeys – thatderived from the formula

P = 200w + 50 (w – 0.3)(n – 1),

where P = the number of people that canbe accommodated;

w = the width of the escape stair(in metres); and

n = the number of storeys servedby the stair.

Phased evacuation1.49 In certain buildings it may beadvantageous to design the escape stairwayson the concept of phased evacuation. Withphased evacuation the first people to beevacuated are those on the floor of the fire andthe floor above together with those in thebuilding who have reduced mobility.

Subsequently, if there is a need to evacuatemore people, it shall be done two floors at atime.

In such a building, or part of a building –

(a) every escape stairway shall be approachedthrough a protected lobby or protected corridorat each storey, other than at a top storeyconsisting exclusively of plant rooms;

(b) every floor shall be a compartment floor;

(c) an automatic sprinkler system complyingwith the relevant recommendations of BS 5306:Part 2: 1990, shall be installed throughout thebuilding where the building has a storey morethan 30 m above ground level;

(d) an automatic fire detection and alarmsystem, to BS 5839: Part 1: 1988, of at least L3standard, shall be installed;

(e) a public address system shall be installedthroughout the building, or part of the building;and

(f) an internal speech communication system,such as a telephone or intercom, shall beinstalled between a control point at fire accesslevel (see Section 5) and every storey.

The systems provided to meet (d) and (e)above, and any similar systems providedelsewhere in the building, shall have controlfacilities to ensure satisfactory separate orcombined operation of any or all systems.

The minimum width of a stair for phasedevacuation shall be that given in Table 1.7 forthe appropriate maximum number of people onthe most heavily occupied storey.

Table 1.5 Minimum width of escape stairs

Situation of stair Maximum number of Minimum stairpeople served(1) width (mm)

1 In a Purpose Group 2(a) building (unlessit will only be used by staff) 150 1000

2 In a Purpose Group 5 building and servingan area used for assembly purposes (unlessthe area is less than 100 m2) 220 1100

3 In a building of any other purpose groupand serving an area with an occupancy ofmore than 50 Over 220 Note (2)

4 Any stair not described above 50 800

Notes –

(1) Assessed as likely to use the stair in a fire emergency.

(2) See Table 1.6 for sizing stairs for total evacuation and Table 1.7 for phased evacuation.

24

Table 1.6 Capacity of escape stairways for total evacuation

Number Maximum number of people accommodated on one stair of widthof floorsserved 1000 mm 1100 mm 1200 mm 1300 mm 1400 mm 1500 mm 1600 mm 1700 mm 1800 mm

1 150 220 240 260 280 300 320 340 3602 190 260 285 310 335 360 385 410 4353 230 300 330 360 390 420 450 480 510

4 270 340 375 410 445 480 515 550 5855 310 380 420 460 500 540 580 620 6606 350 420 465 510 555 600 645 690 735

7 390 460 510 560 610 660 710 760 8108 430 500 555 610 665 720 775 830 8859 470 540 600 660 720 780 840 900 960

10 510 580 645 710 775 840 905 970 1035

Table 1.7 Minimum width of escape stairs for phased evacuation

Maximum number of people in Stair width(2) mmany storey(1)

100 1000120 1100130 1200

140 1300150 1400160 1500

170 1600180 1700190 1800

Notes –

(1) Where the number of people (P) on the most heavily occupied storey is more than 190, the minimum width of theescape stair (Wmm) shall be calculated from W = (P x 10) – 100.

(2) Where the stair serves a storey more than 30 m above ground level the width shall not exceed 1400 mm[see paragraph 1.46(d)].

25

Protection of escape stairways1.50 An escape stairway requires protection inorder that it may provide an area of relativesafety during a fire evacuation. The provisionsfor protecting an internal escape stairway aregiven in paragraphs 1.51 to 1.55 and furtherprovisions apply when an escape stairwaypenetrates a compartment floor (see paragraph3.17) or is a firefighting stairway (seeparagraphs 5.2 to 5.5).

An unprotected stairway (accommodationstairway) may form part of an internal route to astorey, exit or final exit provided that the traveldistance complies with paragraph 1.28 and thenumber of people involved is low.

Protected lobbies and protectedcorridors1.51 A protected lobby or protected corridorshall be provided to every escape stairway onevery storey in a building other than the topstorey where –

(a) the escape stairway is the only escapestairway serving the building (or part of thebuilding) and the building (or part of thebuilding) has more than one storey above ormore than one storey below the storeycontaining the final exit from the escapestairway;

(b) the escape stairway serves a storey morethan 20 m above ground level;

(c) the building is designed for phasedevacuation and the top storey consistsexclusively of plant rooms; or

(d) the discounting stairway provisions havenot been used in calculating escape stairwidths as permitted by paragraph 1.47.

A protected lobby shall also be providedbetween an escape stairway and a place ofspecial fire risk, and that lobby shall have eithernot less than 0.4 m2 of permanent ventilation orbe protected from the ingress or smoke by amechanical smoke control system.

Exits from protected stairways1.52 Every protected stairway shall dischargeeither –

(a) directly to a final exit; or

(b) to a protected exit passageway leadingonly to a final exit.

Where the escape route from an escapestairway also forms the escape route from theground and/or basement storey its width shallbe increased accordingly.

Separation of adjoining protectedstairways and protected exitpassageways1.53 Where two or more protected stairways orprotected exit passageways adjoin they shallbe separated by an imperforate enclosure.

Use of space within protected stairways1.54 A protected stairway, other than afirefighting stairway (see Section 5), shall notcontain any accommodation or services otherthan –

(a) sanitary accommodation or wash roomsprovided that they are not used as acloakroom;

(b) a lift, provided that in a building (or part ofa building) with a single escape stairway the liftmotor room is over the lift shaft or outside theprotected stairway; and

(c) where it is not the only protected stairwayin a building (or part of a building) –

(i) a reception desk or enquiry office areahaving an area of not more than 10 m2

and located at ground or access level; or

(ii) a cupboard formed by fire-resistingconstruction.

Basement stairways1.55 Where an escape stairway forms part ofthe only escape route from an upper storey of abuilding (or part of a building) it shall not servea basement storey.

Where there is more than one escape stairwayfrom an upper storey of a building (or part of abuilding) at least one shall terminate at groundstorey level. Other stairways may connect to abasement storey provided that they areprotected at each basement level by aprotected lobby or protected corridor.

26

External walls adjacent to protectedstairways1.56 Where a protected stairway projectsbeyond, is recessed from, or is in an internalangle of the external walls of the building – thedistance between any unprotected areas (seeSection 4) in the adjacent external walls of thebuilding and an unprotected area in theexternal walls of the protected stairway shall benot less than 1.8 m (see Diagram 1.8).

External escape stairs1.57 Where more than one escape route isavailable from a storey (or part of a building)one of those routes may be by way of anexternal escape stair provided that in the caseof –

(a) a building of Purpose Group 5 – the routeis not intended for use by members of thepublic; or

(b) a building of Purpose Group 2 – the routeserves only staff accommodation (office orresidential).

1.58 Where an external stair is part of anescape route –

(a) the stair shall be protected from theweather when it serves a floor or flat roof morethan 6 m above ground level. The degree ofprotection from the weather will depend on theexposure of the stair;

(b) all doors giving access to the stair shall befire-resisting except at the top of any stairwhich leads downwards;

(c) any part of the external walls within 1.8 mhorizontally, 1.8 m above, and 9 m below theflights and landings of the stair shall be of fire-resisting construction as shown on Diagram1.9; and

(d) the external walls of the building within 3 mof the escape route from the bottom of the stairshall be fire-resisting to a height of 1.8 m abovethe escape route.

Diagram 1.8 External walls adjacent to protected stairways

see para 1.56

(a) Projecting stairway (b) Recessed stairway (c) Internal angle

Key

fire-resisting walls

external walls whichmay be unprotectedareas

accommodation

stairway

accommodation

stairway

accommodation

accommodation

accommodation

accommodation

stairway

1.8m

1.8m

1.8m

1.8m

1.8m

27

see para 1.41 and 1.58

Diagram 1.9 Fire resistance of external walls adjacent to externalescape routes

window – 30 minutesfire resistancefixed shut

door – no fire resistancerequired

F.D.

F.D.

1.8m

1.8m 1.8m

9m

elevation a

Example A

elevation b1

Example B

F.D.

6m maximumfor stair to beunprotected fromthe weather

1.8m

1.8m

1.8m

3m

1.8m

elevation b2

1.8m

1.8m

3m

F.D.

Key

fire-resisting door

fire-resisting area of wallplan b escape

route

28

General provisions1.59 The provisions in paragraphs 1.60 to 1.75relate to the construction and protection ofescape routes, some service installations andother matters associated with the design ofescape routes.

Fire resistance1.60 Details of fire resistance test criteria andstandards of performance are given inSection 3.

All walls, partitions and other enclosures(including roofs that form part of an escaperoute) required to have fire resistance to meetthe provisions of this Section shall have theappropriate performance given in Tables 3.1and 3.2. Where glazed elements in suchenclosures are only able to satisfy the relevantperformance in respect of integrity (i.e.uninsulated glazing), their use shall be limitedin accordance with Table 1.8.

All doors required to have fire resistance tomeet the provisions of this Section shall havethe appropriate performance given in Table 3.5,shall be self-closing and the extent of anyuninsulated glazing shall be in accordance withTable 1.8.

Seating and gangways1.61 Permanent or retractable seating forclosely seated audiences or spectators shall bedesigned in accordance with Clauses 8.1 to 8.4of BS 5588: Part 6: 1991.

Doors on escape routes1.62 Doors on escape routes, whether firedoors or not, shall only be fitted with locks orfastenings which are readily operated from theside approached by a person making anescape. The operation of such a lock orfastening shall not involve the use of a key orthe manipulation of more than one mechanism.

Direction of opening of doors1.63 Doors on escape routes shall, as far aspracticable, open in the direction of escape.Doors shall always open in the direction ofescape in the following situations –

(a) from a place of special fire risk;

(b) in the case of a building of Purpose Group6 or 7 – where the number of occupants ismore than 10; and

(c) in the case of a building of any otherpurpose group – where the number of peoplelikely to use the door in the event of a fire ismore than 50.

Doors on escape routes shall open through notless than 90° and swing clear of any change infloor level, other than a threshold or single step(with a rise of not more than 180 mm) on theline of the doorway. At no point of its swingshall a door reduce the effective width of anyescape route across a landing.

A door that opens towards a corridor shall berecessed to prevent its swing from encroachingon the effective width of the corridor.

1.64 Revolving and automatic doors andturnstiles shall not be permitted across escaperoutes unless they –

(a) have swing doors of the required widthimmediately adjacent;

(b) are easily openable in an emergency; or

(c) fail safely in the open position.

Vision panels in doors1.65 A vision panel, of not less than 0.1 m2,shall be provided in a door that subdivides acorridor, or where a door swings both ways.

Height and width of escape routes1.66 All escape routes shall have a clearheadroom of not less than 2 m and there shallbe no projections below this height, except fordoor frames.

The width of an escape route shall bemeasured at 1.5 m above floor level or pitchline. The projection of handrails and doorframes, if less than 100 mm, and stringers, ifless than 30 mm, on either or both sides shallbe ignored.

The width of an escape door from a room shallbe taken as the width of the door leaf orleaves.

29

Table 1.8 Limitations on the use of uninsulated glazing in enclosures and fire doors on escape routes

Permitted extent of glazing in parts of abuilding with access to –

Position of glazed element A single stair More than one stair

Walls Door leaf Walls Door leaf

A Purpose Group 1(b) and (c)

1 Within the enclosures of a Fixed Unlimited Fixed Unlimitedprotected stairway or within fanlights fanlightsfire-resisting separation only onlyshown in Diagram 1.1

B All other purpose groups

2 Between residential/sleeping Nil Nil Nil Nilaccommodation and a commonescape route (corridor, lobbyor stair)

3 Between a protected stairway(1) Nil 25% of door Nil below 50% ofand – area 1.1m door

unlimited area(i) the accommodation; or above

1.1m(ii) a corridor which is not

a protected corridor.Other than in item 2 above

4 Between – Nil below Nil below Nil below Nil below1.1m 0.1m 0.1m 0.1m

(i) a protected stairway and unlimited unlimited unlimited unlimiteda protected lobby or above 1.1m above 0.1m above 0.1m above 0.1mprotected corridor; or

(ii) accommodation and aprotected lobby.

Other than in item 2 above

5 Between the accommodation Nil below Nil below Nil below Nil belowand a protected corridor 1.1m 0.1m 0.1m 0.1mforming a dead end. unlimited unlimited unlimited unlimitedOther than in item 2 above above 1.1m above 0.1m above 0.1m above 0.1m

6 Between accommodation and Not Not Nil below Nil belowany other corridor; or applicable applicable 0.1m 0.1msubdividing corridors. unlimited unlimitedOther than in item 2 above above 0.1m above 0.1m

Notes –

All heights shall be measured vertically from the floor, the landing level, or the stair pitch line.

(1) If the protected stairway is also a protected shaft (see Section 3) or a firefighting stairway (see Section 5) there maybe further restrictions on the uses of glazed elements.

30

Construction of escape stairs1.67 Other than in a dwellinghouse everyescape stair and its associated landings shallbe constructed of materials of limitedcombustibility where –

(a) it is the only stair serving the building (orpart of the building), unless the building is oftwo or three storeys and is of Purpose Group1(a);

(b) it is within a basement storey, unless it iswithin a maisonette;

(c) the height to any storey which it serves ismore than 20 m above ground or final exitlevel;

(d) it is a firefighting stairway (see Section 5);or

(e) it is external, except in the case of a stairthat connects the final exit level with a floor orflat roof less than 6 m above or below final exitlevel.

Combustible materials may be added to theupper surface of these stairs except in the caseof firefighting stairways.

Helical stairs and spiral stairs1.68 Where helical stairs or spiral stairs formpart of an escape route they shall be designedin accordance with BS 5395: Part 2: 1984 andshall be of Type E (public stair) where they areintended to be used by the public.

Final exits1.69 A final exit shall –

(a) have a width not less than the width of theescape route it serves;

(b) be sited to ensure rapid dispersal to aplace of safety;

(c) be readily apparent to people who need touse it; and

(d) be sited clear of any risk from fire or smokeissuing from a basement, and from openings totransformer rooms, solid waste stores, boilerrooms and similar risks.

Lighting of escape routes1.70 Other than in a dwellinghouse all escaperoutes shall have adequate artificial lighting.The areas listed in Table 1.9 shall also haveescape lighting installed in accordance with BS5266: Part 1: 1988 or CP 1007: 1955, whichwill illuminate the escape route if the mainssupply fails.

Escape lighting to escape stairways shall be ona separate circuit to that supplying any otherpart of the escape route or building.

Protected power circuits1.71 A protected power circuit shall consist ofcable meeting the requirements forclassification as CWZ in accordance with BS6387: 1994. The circuit shall be separate fromany circuit provided for any other purpose andshall be routed only through those areas of thebuilding in which the fire risk is negligible.

Exit signs1.72 Other than in a dwellinghouse, exits onescape routes except those in normal use foregress, shall be marked with signs which arereadily visible so that the occupants of abuilding can clearly and readily see where theexits are.

The signs shall comply with the relevantrequirements of BS 5499: Part 1: 1990.

Fire protection of lifts1.73 In general, it is not appropriate to use alift when there is a fire in the building. However,as lifts penetrate floors and are usually sitedwithin or adjacent to circulation routes they mayprejudice the means of escape from thebuilding. To safeguard against this a lift and itsassociated machine room shall comply with thefollowing provisions. (In some circumstances asuitably sited and protected lift containingcertain safety features may be used forevacuating disabled people and detailsconcerning such lifts are given in BS 5588: Part8: 1988.)

A lift shall be –

(a) in a protected shaft where it penetrates acompartment floor (see paragraph 3.17);

(b) within the enclosure of a protected stairwaywhere permitted by paragraph 1.54; or

(c) enclosed with fire-resisting constructionwhere its siting prejudices the means ofescape.

A lift shall not be continued down to serve abasement storey in a building (or part of abuilding) the upper storeys of which are servedby a single escape stairway or if the lift is withinthe enclosure to an escape stairway which isterminated at ground level.

31

A lift in a basement or enclosed car park shallbe approached through a protected lobby orprotected corridor unless it is in a protectedstairway enclosure.

A lift shall be approached through a protectedlobby or protected corridor on a storey whichcontains a high fire risk area, if the lift alsodelivers directly into a corridor serving sleepingaccommodation.

Lift machine rooms shall be sited over the liftshaft where practicable. Where the lift is withina protected stairway which is the only protectedstairway in a building (or part of a building) themachine room shall be located outside theprotected stairway, if it cannot be sited over thelift shaft.

Mechanical ventilation systems1.74 A mechanical ventilation system shall bedesigned so that in a fire either –

(a) the air movement in the building is directedaway from escape routes; or

(b) the system is closed down.

Where the system re-circulates air it shallcomply with the provisions of BS 5588: Part 9:1989 in respect of its operation under fireconditions.

Where a pressurization system is installed in aprotected stairway all mechanical ventilationand air conditioning systems in the buildingshall be compatible with it when operatingunder fire conditions.

Waste chutes and storage1.75 A room used for the storage of waste orcontaining a waste chute shall be –

(a) separated from other parts of the buildingby fire-resisting construction;

(b) located outside protected stairways andprotected lobbies; and

(c) accessed from the open air or from aprotected lobby which has not less than 0.2 m2

of permanent ventilation.

Table 1.9 Provisions for escape lighting

Purpose group of the buildingor part of the building Areas requiring escape lighting

Purpose Group 2 All common escape routes

Purpose Groups 3, 4(1), 6 and 7(a) (a) Underground or windowless accommodation

(b) Stairways in a central core or serving storey(s) morethan 20 m above ground level

(c) Internal corridors more than 30 m long

(d) Open-plan office areas more than 60 m2

Purpose Groups 4(2) and 7(b) All escape routes (except in a shop of not more than threestoreys, with no sales floor greater than 280 m2, providedthat the shop is not a restaurant or bar)

Purpose Group 5 All escape routes and accommodation except for –

(a) accommodation open on one side to view sport orentertainment during daylight hours; and

(b) toilet accommodation having a floor area lessthan 8 m2

All purpose groups (a) Electricity generator rooms

(b) Switch room/battery room for emergency lightingsystem

(c) Emergency control room

Notes –

(1) Those areas of the building to which the public are not admitted.

(2) Those areas of the building to which the public are admitted.

32

2.1 This Section contains provisions to restrictthe spread of flame over the internal wall andceiling linings and, in some locations, to limitthe contribution they will make to the growth ofthe fire. This Section must be read inconjunction with Section 6.

2.2 Provisions regarding linings withinconcealed spaces, above fire-protectingsuspended ceilings and enclosures to sanitarypipework are contained in Section 3. Additionalprovisions regarding the internal surface ofrooflights are contained in Section 4.

2.3 This Section does not contain provisionsregarding the upper surface of floors and stairs.

Classification of performance ofmaterials2.4 The surface spread of flame classificationof a lining shall be ascertained by testing inaccordance with BS 476: Part 7: 1971 or 1987(1993). The classifications given in such testsare Classes 1, 2, 3 and 4. Class 0 is achievedwhere a lining material or the surface of acomposite product is either –

(a) composed throughout of materials of limitedcombustibility; or

(b) a Class 1 material which has when testedto BS 476: Part 6: 1981 or 1989, a firepropagation index (I) of not more than 12 and asub-index (i1) of not more than 6.

A composite material of limited combustibilitywhich does not have a surface complying with(a) or (b) shall be classified by test.

Class 0 is the highest classification and Class 4materials are not acceptable.

2.5 The term thermoplastic material includesall synthetic polymeric materials which have asoftening point lower than 200°C when testedto BS 2782: Part 1: 1976: Method 120A. Forthe purposes of this Section (and Section 4)thermoplastic materials are classified as TP(a)rigid and TP(a) flexible and TP(b) as follows –

(a) To be classified as TP(a) rigid, athermoplastic material shall be –

(i) rigid solid PVC sheet;

(ii) solid polycarbonate sheet not less than3 mm thick;

(iii) double or multiple skin rigid sheet ofunplasticised PVC or polycarbonate whichachieves a classification of Class 1; or

(iv) a rigid product which when tested toBS 2782: Part 5: 1970: Method 508A,extinguishes before the flame reaches thefirst mark and after removal of the burner,the flaming or afterglow does not exceed 5seconds.

(b) To be classified as TP(a) flexible, athermoplastic material shall be a flexibleproduct not greater than 1 mm thick whichcomplies with the Type C requirements ofBS 5867: Part 2: 1980 (1993) when tested toBS 5438: 1989 Test 2 (excluding the cleansingprocedure) with the flame applied to thesurface of the specimens for 5, 15, 20 and 30seconds respectively.

(c) To be classified as TP(b) a thermoplasticmaterial shall be –

(i) rigid solid polycarbonate sheet lessthan 3 mm thick;

(ii) double or multiple skin polycarbonatesheet which does not achieve aclassification of Class 1; or

(iii) a product which, when a specimen ofmaterial between 1.5 mm and 3 mm thick,tested to BS 2782: Part 5: 1970: Method508A, has a rate of burning not greaterthan 50 mm per minute.

2.6 Where a thermoplastic material is used asa lining to protect a wall or ceiling but is notfully bonded to a non-thermoplastic substratethe surfaces of both the thermoplastic materialand the substrate shall meet the provisions ofparagraph 2.8. However, where a thermoplasticmaterial is fully bonded to a non-thermoplasticsubstrate only the surface of the compositeneed meet the provisions of paragraph 2.8.

Section 2 – Internal fire spread – Linings

33

Performance of wall and ceilinglinings2.8 The surface lining of a wall and of a ceilingshall have a classification not lower than therelevant Class given in Table 2.1, subject to theprovisions of paragraphs 2.9 to 2.14.

2.9 In a room any part of the surface of a wallmay be of a Class lower than that given inTable 2.1 (but not lower than Class 3) if thetotal area of those parts in any one room doesnot exceed either –

(a) half the floor area of the room; or

(b) (i) in the case of a building of PurposeGroup 1 or 2 – 20 m2; or

(ii) in the case of a building of any otherpurpose group – 60 m2,

whichever is the lesser.

2.10 A suspended ceiling which is to contributeto the fire resistance of a floor/ceiling assemblyhaving a fire resistance of more than 60minutes shall, in addition to having theclassification given in Table 2.1, be constructedof materials of limited combustibility.

2.11 The ceiling of a room may be constructed,either as a suspended or stretched skinmembrane, from panels of a thermoplasticmaterial of the TP(a) flexible classificationprovided that –

(a) each panel is supported on all its sides;

(b) each panel is not more than 5 m2 in area;and

(c) it is not a fire-resisting ceiling.

Definition of wall and ceiling2.7 For the purposes of the performance ofwall and ceiling linings –

(a) a wall shall include –

(i) the surface of glazing (except glazingin a door); and

(ii) any part of a ceiling which slopes at anangle of more than 70° to the horizontal;

(b) a wall shall not include –

(i) doors and door frames;

(ii) window frames and frames in whichglazing is fitted;

(iii) architraves, cover moulds, picturerails, skirtings and similar narrowmembers; and

(iv) fire surrounds, mantleshelves andfitted furniture;

(c) a ceiling shall include –

(i) the surface of glazing; and

(ii) any part of a wall which slopes at anangle of 70° or less to the horizontal; and

(d) a ceiling shall not include –

(i) trap doors and their frames;

(ii) the frames of windows or rooflightsand frames in which glazing is fitted; and

(iii) architraves, cover moulds, picture railsand similar narrow members.

Table 2.1 Surface classifications for walls and ceilings

Type of Room or circulation space Class of surface for bothbuilding walls and ceilings

Purpose Rooms not exceeding 4 m2 3Groups 1and 2 All other rooms 1

Circulation spaces (within a dwelling) 1

Circulation spaces (common areas) 0

All other Rooms not exceeding 30 m2 3purposegroups All other rooms 1

Circulation spaces 0

34

Rooflights2.12 Other than in a protected stairway arooflight may be of a classification lower thanthe relevant Class given in Table 2.1 providedthat –

(a) where it is –

(i) a plastic material which has a lowersurface with a classification not lower thanClass 3; or

(ii) a thermoplastic material which has alower surface with a classification notlower than Class 3 or is classified as aTP(a) rigid or TP(b) product,

the size of the rooflight does not exceed therelevant maximum area given in Table 2.2; and

(b) where there is more than one rooflight inthe ceiling of a room or space –

(i) the area of rooflights does not exceedthe relevant maximum total area given inTable 2.2; and

(ii) the disposition of the rooflightscomplies with the limitations given inDiagram 2.1.

The upper surface of a rooflight is subject tothe provisions of Section 4.

Windows2.13 A window in the external wall of acirculation space and all internal glazed areasshall be glazed with a material having aclassification not lower than that given inTable 2.1.

A window in an external wall of a room may beglazed with a thermoplastic material classifiedas a TP(a) rigid product.

Lighting diffusers2.14 This paragraph applies to a lightingdiffuser which forms part of a ceiling. It doesnot apply to the diffuser of a light fitting which isattached to the soffit of, or suspended beneath,a ceiling.

Lighting diffusers may be translucent or open-structured elements and may be part of a lightfitting or be used below a rooflight or othersource of light.

A thermoplastic lighting diffuser shall not beincorporated in a fire-protecting or fire-resistingceiling unless it has been satisfactorily testedas part of a luminaire within a ceiling assemblythat provides the appropriate fire resistance. Aceiling in a room or in a circulation space (otherthan a protected stairway) may incorporate athermoplastic lighting diffuser provided that –

(a) the wall and ceiling surfaces exposedwithin the space above the ceiling (other thanthe upper surface of the lighting diffuser)comply with the classification given in Table 2.1for the space below the ceiling; and

(b) the lighting diffuser is either –

(i) classified as a TP(a) rigid product; or

(ii) classified as a TP(b) product and isloosely mounted so that it will fall out of itsmounting on initial heating. Where morethan one such lighting diffuser is fitted,they shall be limited in their extent inaccordance with Table 2.2. Small lightingdiffusers may be grouped together (seeNote (1) to Table 2.2 and Diagram 2.1).

35

Table 2.2 Limitations on Class 3 plastic rooflights and thermoplasticrooflights and lighting diffusers in suspended ceilings

Maximum total area ofMinimum Use of space Maximum area of rooflights or diffuser Minimum separation

classification below each rooflight panels as a percentage distance betweenof lower rooflight or or diffuser of floor area of the rooflights orsurface diffuser panel(1) space in which the diffuser panels(1)

ceiling is located(m2) (%) (m)

TP(a) Rooms or No limit(2) No limit No limitcirculation spaces(except protectedstairways)

Class 3(3) or Rooms 5 50 3TP(b)

Circulation spaces(except protected 5 15 3stairways)

Notes –

(1) Small rooflights or diffuser panels may be grouped together provided that the overall size of the group and the spacebetween one group and any others comply with the limitations given in Diagram 2.1.

(2) Lighting diffusers of a TP(a) flexible material are limited to panels of not more than 5 m2 (see paragraph 2.11).

(3) There are no limitations on Class 3 materials in certain small rooms (see Table 2.1).

see para 2.12(b), 2.14(b) and Table 2.2 note(1)

Diagram 2.1 Limitations on groups of class 3 plastic rooflights and TP(b)thermoplastic rooflights and lighting diffusers in suspendedceilings

separate groupof rooflightsor lightingdiffusers

5m max. 5m max.3m min.

(betweengroups)

3m min.(betweengroups)

5m max.

rooflight orlightingdiffuser

Key

36

3.1 The spread of fire within a building canbe restricted by –

(a) ensuring the elements of structure andcertain other components of the building have aminimum standard of fire resistance;

(b) subdividing the building into compartmentswith fire-resisting construction;

(c) subdividing concealed and extensivecavities within the construction; and

(d) protecting openings in, and penetrationsthrough, fire-resisting construction.

Where a building is divided into separated partsby a compartment wall (or walls), running thefull height of the building in a continuousvertical plane, the provisions of this Sectionmay be applied separately to each separatedpart.

Tests for fire resistance3.2 The fire resistance of an element ofstructure or other component of a building is ameasure of its ability to withstand the effects offire in one or more of the following ways –

(a) resistance to collapse (loadbearingcapacity);

(b) resistance to fire penetration (integrity); and

(c) resistance to transfer of excessive heat(insulation).

Tests for fire resistance shall be in accordancewith, in the case of –

(i) loadbearing elements – BS 476: Parts 20and 21: 1987;

(ii) non-loadbearing elements – BS 476: Parts20 and 22: 1987;

(iii) suspended ceilings – BS 476: Parts 20and 23: 1987;

(iv) ventilation ducts – BS 476: Parts 20 and24: 1987; and

(v) any element of construction tested prior to1 January 1988 – BS 476: Part 8: 1972.

A provision for an element of structure or othercomponent of the building to have a specificperiod of fire resistance means that it shallhave not less than that period, in respect of therelevant aspects of performance given in Table 3.1.

Fire resistance of elements ofstructure and certain othercomponents of the building

3.3 An element of structure and those othercomponents of the building given in Table 3.1shall have a minimum period of fire resistanceof not less than that given in Tables 3.1 and 3.2for the purpose group of the building.

Where one element of structure or othercomponent supports, carries or gives stabilityto another, the fire resistance of the supportingelement or component shall be not less thanthe minimum period of fire resistance for theother element (whether that other element isloadbearing or not).

Where an element or structure or othercomponent forms part of more than onebuilding or compartment, the fire resistance ofthat element or component shall be not lessthan the greater of the relevant provisions.

Section 3 – Internal fire spread – Structure

37

Table 3.1 Specific provisions of test for fire resistance of elements ofstructure and other components of a building

Minimum provisions when tested to therelevant part of BS 476 (minutes)

Part of building Method ofLoadbearing exposurecapacity(1) Integrity Insulation

1 Structural frame, See Table 3.2 Not applicable Not applicable Exposed facesbeam or column

2 Loadbearing wall See Table 3.2 Not applicable Not applicable Each side(which is not also separatelya wall describedin any of thefollowing items)

3 Floors –

(a) in upper storey 30(2) 15(2) 15(2)

of two storeydwellinghouse From underside(but not over agarage)

(b) any other See Table 3.2 See Table 3.2 See Table 3.2floor

4 Roofs –

(a) any part 30 30 30forming anescape route From underside

(b) any roof that See Table 3.2 See Table 3.2 See Table 3.2performs thefunction of a floor

5 External walls –

(a) any part less See Table 3.2 See Table 3.2 See Table 3.2 Each sidethan 1 m from separatelyany point onthe relevantboundary

(b) any part 1 m or See Table 3.2 See Table 3.2 15(3) From insidemore from therelevantboundary

6 Compartment wall 60 or see 60 or see 60 or see Each sideseparating Table 3.2 Table 3.2 Table 3.2 separatelyoccupancies (whichever is (whichever is (whichever is

less) less) less)

7 Compartment wall See Table 3.2 See Table 3.2 See Table 3.2 Each sideother than in item 6 above separately

38

Table 3.1 Specific provisions of test for fire resistance of elements ofstructure and other components of a building

Minimum provisions when tested to therelevant part of BS 476 (minutes)

Part of building Method ofLoadbearing exposurecapacity(1) Integrity Insulation

8 Protected shafts,excluding anyfirefightingshafts –

(a) any glazing Not applicable 30 No provision(4)

described inparagraph 3.19

(b) any other part 30 30 30 Each sidebetween the separatelyshaft and aprotected lobbyor protectedcorridordescribed inparagraph 3.19

(c) any part not See Table 3.2 See Table 3.2 See Table 3.2described in(a) or (b)above

9 Enclosure (whichdoes not formpart of acompartment wallor a protectedshaft) to a –

(a) protected 30 30 30(5) Each sidestairway separately

(b) lift shaft 30 30 30

(c) service shaft 30 30 30

10 Firefightingshafts –

(a) construction 120 120 120 From sideseparating remote fromfirefighting shaftshafts fromremainder ofbuilding 60 60 60 From shaft

side

(b) constructionwithin afirefightingshaftseparatingfirefighting 60 60 60 Each sidestairway, firefighting separatelylift shaft andfirefighting lobby

39

Table 3.1 Specific provisions of test for fire resistance of elements ofstructure and other components of a building

Minimum provisions when tested to therelevant part of BS 476 (minutes)

Part of building Method ofLoadbearing exposurecapacity(1) Integrity Insulation

11 Enclosure (whichis not acompartment wall ordescribed in item 8)to a –

(a) protected lobby 30 30 30(5) Each sideseparately

(b) protected 30 30 30(5)

corridor

12 Subdivision of a 30 30 30(5) Each sidecorridor separately

13 Wall separating an 30 30 30 From garageattached or sideintegral garagefrom a dwellinghouse

14 Fire-resisting 30 30 30(5) Each sideconstruction in separatelydwellings notdescribed elsewhere

15 Cavity barrier Not applicable 30 15 Each sideseparately

16 Ceiling shown in Not applicable 30 30 From undersideDiagram 3.6 or 3.7

17 Fire-resisting duct Not applicable 30 No provision From outsidereferred to inparagraph 3.33(e)

18 Casing around a Not applicable 30 No provision From outsidedrainage systemas shown inDiagram 3.11

19 Flue walls Not applicable See Table 3.2 See Table 3.2 From outsidedescribed inparagraph 3.36

20 Fire doors See Table 3.5

Notes –

(1) Applies to loadbearing elements only.

(2) This standard of fire resistance is referred to as modified 30 minutes.

(3) 30 minutes for any part adjacent to an external escape route (but no provision for glazed elements in respect ofinsulation).

(4) Except for any limitations on glazed elements given in Table 1.8.

(5) See Table 1.8 for permitted extent of uninsulated glazed elements.

40

Table 3.2 Minimum periods of fire resistance

Minimum period (minutes) for elements of structure andother components of the building forming part of

Basement storey+

including floor Ground or upper storeyover

Purpose group of buildingHeight (m) of top floor above

Depth (m) of ground in building or separatedbasement part of building(1)

Morethan 5 More

More Not more Not not than 20 More thanthan 10 than 10 more more not more 30

than 5 than than 3020

1 Residential (dwellings) –

(a) flats andmaisonettes 90 60 30* 60(2)** 90** 120**

(b) and (c) Not 30* 30* 60@ Not Notdwellinghouses relevant relevant relevant

2 Residential –

(a) institutional 90 60 30*## 60 90 120#

(b) other residential 90 60 30* 60 90 120#

3 Office –Not

not sprinklered 90 60 30* 60 90 permitted

sprinklered(3) 60 60 30* 30* 60 120#

4 Shop and commercial –Not

not sprinklered 90 60 60 60 90 permitted

sprinklered(3) 60 60 30* 60 60 120#

5 Assembly and recreation –Not

not sprinklered 90 60 60 60 90 permitted

sprinklered(3) 60 60 30* 60 60 120#

6 Industrial –Not

not sprinklered 120 90 60 90 120 permitted

sprinklered(3) 90 60 30* 60 90 120#

41

Table 3.2 Minimum periods of fire resistance

Minimum period (minutes) for elements of structure andother components of the building forming part of

Basement storey+

including floor Ground or upper storeyover

Purpose group of buildingHeight (m) of top floor above

Depth (m) of ground in building or separatedbasement part of building(1)

Morethan 5 More

More Not more Not not than 20 More thanthan 10 than 10 more more not more 30

than 5 than than 3020

7 Storage and other non-residential

(a) any building or partnot described elsewhere –

Notnot sprinklered 120 90 60 90 120 permitted

sprinklered(3) 90 60 30* 60 90 120#

(b) car park for lightvehicles –

(i) open sided car Not Not 15*$ 15*$ 15*$ Notpark(4) applicable applicable applicable

(ii) any other car park 90 60 30* 60 90 120#

Notes –

+ The floor over a basement (or if there is more than one basement, the floor over the topmost basement) shall meetthe provisions for the ground and upper storeys if that period is higher.

* Increased to a minimum of 60 minutes for compartment walls separating buildings.

** Reduced to 30 minutes for any floor within a maisonette, but not if the floor contributes to the support of the buildingas a whole.

@ Reduced to 30 minutes for a dwellinghouse having not more than three storeys and for the wall or floor separating adwellinghouse from an attached or integral garage.

## Multi-storey hospitals designed in accordance with NHS Firecode documents shall have a minimum of 60 minutes.

$ Increased to a minimum of 30 minutes for elements protecting the means of escape.

# Reduced to 90 minutes for elements not forming part of the structural frame.

(1) A single storey building or a single storey separated part of a building shall be subject to the period given under theheading “not more than 5” and where it has a basement storey or storeys they shall be subject to the period appropriateto their depth.

(2) Reduced to 30 minutes where an existing building of not more than three storeys is being converted.

(3) “Sprinklered” means that the building is fitted throughout with an automatic sprinkler system complying with therelevant requirements of BS 5306: Part 2: 1990 in respect of occupancy rating and additional requirements for lifesafety.

(4) Car parks which comply with paragraphs 3.40 and 3.41.

42

Fire protecting suspended ceilings3.4 A suspended ceiling will only be acceptedas contributing to the fire resistance of a floorwhere that ceiling is of the appropriate typegiven in Table 3.3.

Fire-resisting construction3.5 Where an element of structure or othercomponent of the building is required to havefire resistance it may be constructed inaccordance with an appropriate specification inPart II of the Building Research EstablishmentReport – Guidelines for the construction of fire-resisting structural elements (BR 128: 1988).

Variations of the provisions regardingfire resistance3.6 A provision for an element of structure tohave fire resistance shall not apply to –

(a) any part of the structure which onlysupports a roof unless –

(i) the roof performs the function of a floor,e.g. as a means of escape, for parking ofvehicles, etc.;

(ii) the structure is part of, or is essentialfor the stability of an external wall which,under the provisions Section 4, cannot bean unprotected area; or

(iii) the structure is part of or supports acompartment wall or a wall between adwellinghouse and an attached or integralgarage;

(b) in the case of a single storey building or abuilding which consists of a ground storey andone or more basement storeys – any elementof structure which forms part of the groundstorey unless the element –

(i) supports a gallery; or

(ii) is located as defined in sub-paragraph(a)(ii) or (iii);

(c) the lowest floor of a building; and

(d) a platform floor.

Table 3.3 Limitations of fire-protecting suspended ceilings

Type ofHeight of building Fire resistance of floor suspendedor separated part Type of floor required by Table 3.2 ceiling

(m) (minutes) (see notes)

Not compartment 60 or lessA, B, C or D

Less than 20 Less than 60Compartment

60 B, C or D

20 or more Any 60 or less C or D

No limit Any More than 60 D

Notes –

Ceiling type Description

A Surface of ceiling exposed to the cavity shall be Class 0 or Class 1.

B Surface of ceiling exposed to the cavity shall be Class 0.

C Surface of ceiling exposed to the cavity shall be Class 0.Ceiling shall not contain easily openable access panels.

D Ceiling shall be of a material of limited combustibility and not contain easily openable access panels.Any insulation above the ceiling shall be of a material of limited combustibility.

Any access panels provided in fire-protecting suspended ceilings of Type C or D shall be secured in position byreleasing devices or screw fixings, and they shall be shown to have been tested in the ceiling assembly in which they areincorporated.

43

3.7 Where one side of a basement storey orcompartment is (due to the slope of theground) open at and provides means of escapeand fire brigade access at ground level andsmoke venting, the period of resistance for theelements of structure and other components ofthe building in that basement storey orcompartment shall be that appropriate to astorey above the ground.

3.8 Where the roof space of an existing twostorey dwellinghouse is to be converted to forma new storey the provisions of this Section arefor the floors, both old and new, to have full 30minutes fire resistance. However, the existingfirst floor construction need not be upgradedwhere it separates rooms provided –

(a) only one storey is being added;

(b) the new storey contains not more than twohabitable rooms;

(c) the total area of the new storey is not morethan 50 m2; and

(d) it has at least modified 30 minutes fireresistance.

Raised storage floors3.9 Raised free-standing floors supported byracking are frequently erected for storagepurposes and whether they are considered asa gallery or as a floor forming a storey theprovisions for fire resistance for elements ofstructure apply.

In the case of automated storage systemswhere people do not normally frequent any ofthe raised storage tiers it is not necessary toprovide the storage structure with fireresistance.

Where people frequent the storage tiers in thecourse of their normal use the provisions forfire resistance for the raised storage floor andits supporting structure may be dispensed withwhere the number of persons likely to be onthe raised floor at any one time is low (anddoes not include members of the public) andthe raised floor –

(a) is within a single storey building orcompartment and is structurally free-standing;

(b) consists of only one tier with the spaceboth above and below used only for storagepurposes;

(c) is served by a stair or stairs to comply withthe relevant maximum travel distance given inTable 1.2 and at least one stair dischargeswithin 4.5 m of an exit from the building orcompartment;

(d) has a surface classification on theunderside not lower than Class 3 (seeparagraph 2.4); and

(e) is designed and constructed so that anypersons on the floor will be readily aware of afire starting on the lower level. Design andconstruction features include the use ofperforations in the floor, leaving a spacebetween the floor and the walls of the spacehousing it and automatic fire detection andalarm systems. However, where the length orwidth of a raised storage floor is greater than10 m an automatic fire detection and alarmsystem shall be provided to give warning of afire below the floor.

Compartmentation3.10 The degree to which a building orseparated part of a building is subdivided intocompartments is related to the use of and thefire load in the building, the height to the topstorey and the provision or otherwise of asprinkler system. Compartmentation may assistin meeting the provisions of Section 1 orSection 4 of this Technical Booklet.

For compartmentation to be effective thereshall be continuity at the junctions of the fire-resisting elements enclosing the compartmentand any opening from one compartment toanother shall not present a weakness. Thespaces which connect compartments, e.g.stairs, service shafts, etc. shall be enclosed toform protected shafts and their walls and floorsshall be constructed as compartment walls andcompartment floors.

Provision of compartment walls andcompartment floors3.11 In buildings of all purpose groups –

(a) a compartment wall shall be constructedwhere a wall –

(i) is common to two or more buildings; or

(ii) is provided to divide a building intoseparated parts; and

(b) a compartment wall or a compartment floor,as appropriate shall be constructed –

(i) to separate parts of a building whichare in different purpose groups (seeparagraph 6.2); and

(ii) where a wall or floor is provided todivide a building into different occupancies(i.e. ownership, tenancies or similar).

44

3.12 The following walls or floors shall beconstructed as compartment walls orcompartment floors –

(a) In a building of Purpose Group 1(b) or (c) –

(i) a wall which separates semi-detacheddwellinghouses or dwellinghouses in aterrace (in these cases eachdwellinghouse shall be treated as aseparate building); and

(ii) a wall or floor which separates adwellinghouse from an attached or integralgarage;

(b) in a building of Purpose Group 1(a) –

(i) every floor, other than a floor within amaisonette;

(ii) every wall which separates a flat ormaisonette from any other part of thebuilding; and

(iii) every wall enclosing a communalwaste container ;

(c) in a building of Purpose Group 2 –

(i) every floor; and

(ii) in the case of a health care building –

a wall needed to divide a storey intocompartments for means of escapepurposes [see regulation E3(c) and (d)];and

(d) in a building of Purpose Group 3, 4, 5, 6,or 7 –

(i) a wall which is needed to subdivide abuilding, or separated part of a building, sothat the maximum floor area or maximumvolume, as appropriate, of a compartmentgiven in Table 3.4 is not exceeded;

(ii) every floor in a building or a separatedpart of a building (other than the lowestfloor) where that building or separated parthas a floor at a height of more than 30 mabove ground level;

(iii) the floor of the ground storey where abuilding or separated part of a building hasone or more basements; and

(iv) every basement floor in a building, ora separated part of a building (other thanthe lowest basement floor), where thatbuilding or separated part has a floor at adepth of more than 10 m below groundlevel.

Table 3.4 Maximum floor areas and volumes of buildings or compartmentshaving more than one storey

Height of top storey Floor area of any one MaximumPurpose group of building of building above storey in the building compartment

(or part) ground level (m) or compartment (m2) volume (m3)

3 No limit No limit No limit

4 and 5 Not sprinklered No limit 2000 No limit

Sprinklered(1) No limit 4000 No limit

6(3) Not sprinklered Not more than 20 7000 No limitMore than 20 2000(2) No limit

Sprinklered(1) Not more than 20 14000 No limitMore than 20 4000(2) No limit

7(a)(3) Not sprinklered Not more than 20 No limit 20000More than 20 No limit 4000(2)

Sprinklered(1) Not more than 20 No limit 40000More than 20 No limit 8000(2)

7(b) No limit No limit No limit

Notes –

(1) “Sprinklered” means that the building is fitted throughout with an automatic sprinkler system meeting the relevantrecommendations of BS 5306: Part 2: 1990, i.e. the relevant occupancy rating together with the additionalrequirements for life safety.

(2) This reduced limit applies only to those storeys which are more than 20 m above ground level.

(3) There may be additional limitations on floor area, volume and/or sprinkler provisions in certain industrial and storageuses under other legislation.

45

Construction of compartment walls andcompartment floors3.13 Every compartment wall andcompartment floor shall –

(a) form a complete barrier to fire between thecompartments they separate; and

(b) have the appropriate fire resistancerequired by paragraph 3.3.

A compartment wall between two or morebuildings shall extend the full height of thebuildings in a continuous vertical plane. Thusadjoining buildings shall be separated only bywalls and not by floors.

A compartment wall used to form a separatedpart of a building shall extend the full height ofthe building in a continuous vertical plane. Thusseparated parts shall be separated only bywalls and not by floors.

Junctions of compartment walls andcompartment floors with other walls3.14 Where a compartment wall orcompartment floor meets a compartment wallor an external wall the junction shall maintainthe fire resistance for a period of not less thanthe period of fire resistance required by thecompartment wall or compartment floor.

Junction of compartment walls androofs3.15 Where a compartment wall meets a roof itshall either –

(a) be extended up through the roof to a heightof not less than 375 mm above the top surfaceof the roof covering; or

(b) where the roof covering has a designationof AA, AB or AC (see paragraph 4.18), on asubstrate or deck of a material of limitedcombustibility, for a width of not less than 1.5 mon either side of the junction [see Diagram3.1(a)] – be taken up to meet the underside ofthe roof covering or deck and the junction firestopped. However, where the building is ofPurpose Group 1, 2(b), 3 or 5 and is not morethan 15 m in height a combustible substrate oftimber boarding, wood wool slabs or timbertiling battens may be carried over thecompartment wall provided it is fully bedded inmortar, or no less suitable material, over theentire width of the wall [see Diagram 3.1(b)].

Openings in compartment walls whichseparate buildings or occupancies3.16 A compartment wall which is common totwo or more buildings, or which separatesdifferent occupancies in the same building,shall have no openings other than those for –

(a) means of escape in case of fire – when afire resisting self-closing door (see paragraphs3.22 to 3.26 having the same period of fireresistance as that of the compartment wall shallbe provided; and

(b) the passage of a pipe – when the openingin the wall shall comply with paragraphs 3.34and 3.37 to 3.39.

see para 3.15(b)

Diagram 3.1 Junction ofcompartment walland roof

1.5m

fire stopping

substrate/decka material oflimited combustibility

(a) Any building

AA, AB or AC roof covering

AA, AB or AC roof covering

1.5m

1.5m 1.5m

mortarbedding

slates/tiles

timber battens

sarking felt

(b) Building of Purpose Group1, 2(b), 3 or 5 not more than15m in height

46

Openings in other compartment wallsand in compartment floors3.17 A compartment wall (other than onedescribed in paragraph 3.16) and acompartment floor shall have no openingsother than those –

(a) having a fire resisting self-closing door (seeparagraph 3.22 to 3.26) and in the case of adoorway between a dwellinghouse and anattached or integral garage, having a thresholdheight of not less than 100 mm (see Diagram3.2);

(b) for the passage of pipes, ventilationducts,chimneys, appliance ventilation duct orduct encasing one or more flue pipes – whenthe opening in the compartment wall orcompartment floor shall comply withparagraphs 3.34 to 3.39;

(c) for a waste chute system constructed ofnon-combustible materials; and

(d) for a protected shaft which complies withthe provisions of paragraph 3.18 to 3.21.

Protected shafts betweencompartments3.18 A protected shaft shall only be used toaccommodate stairs, lifts, escalators, chutes,ducts, pipes, sanitary accommodation andwashrooms. Where a protected shaft containsa protected stairway Section 1 imposesadditional requirements (see paragraphs 1.51to 1.55) and where it contains a firefightingstairway Section 5 imposes additionalrequirements (see paragraphs 5.2 to 5.5).

The construction enclosing a protected shaft,other than a wall which is part of an externalwall, shall –

(a) form a complete barrier to fire between thedifferent compartments which the shaftconnects;

(b) have the same fire resistance as thecompartment through which it is passing, otherthan where a glazed screen complying withparagraph 3.19 is provided; and

(c) satisfy the provisions regarding ventilationin paragraph 3.20 and regarding the treatmentof openings in paragraph 3.21.

Glazed screens in protected shafts3.19 Glazing may be incorporated in the wallbetween a protected shaft containing astairway, and a corridor or lobby which givesaccess to that stairway provided that –

(a) the protected shaft is not a firefightingshaft;

(b) the protected shaft is not required to havemore than 60 minutes fire resistance; and

(c) the glazing has not less than 30 minutesfire resistance in respect of integrity; andeither –

(i) the glazing is limited in extent inaccordance with Table 1.8; or

(ii) the corridor or lobby has not less than30 minutes fire resistance (see Diagram3.3).

see para 3.17(a)

Diagram 3.2 Doorway betweendwellinghouse andgarage

garage

fire-resistingfloor (if any)

fire-resistingself-closingdoor

dwellinghouse

fire-resistingwall

100mm

47

Pipes for oil or gas and ventilation ductsin protected shafts3.20 Where a protected shaft contains –

(a) a stairway and/or a lift it shall not contain –

(i) a pipe conveying oil, other than in themechanism of a hydraulic lift; or

(ii) a ventilation duct, other than a ductprovided for the purposes of pressurizingthe shaft to keep it free from smoke in theevent of fire; and

(b) a pipe conveying flammable gas it shall beadequately ventilated directly to external air byventilation openings at both high and low levelsin the shaft. Any pipe conveying natural gas orLPG shall be of screwed steel or of all weldedsteel construction.

Openings in protected shafts3.21 (a) Where the wall of a protected shaft iscommon to two or more buildings no openingshall be provided in that wall other than for –

(i) means of escape in case of fire – whena fire-resisting self-closing door, having thesame period of fire resistance as theprotected shaft, shall be provided; and

(ii) the passage of a pipe – when theopening shall comply with paragraphs 3.34 and 3.37 to 3.39.

(b) Other than in walls subject to sub-paragraph (a) and external walls, a protectedshaft shall only have openings for –

(i) a fire-resisting self-closing door whichcomplies with paragraph 3.22;

(ii) the passage of a pipe where theopening complies with paragraphs 3.34and 3.37 to 3.39;

(iii) where the shaft is or contains aventilation duct – the inlets to, outlets fromand opening for a ventilation duct whichcomplies with paragraph 3.35;

(iv) where the shaft is pressurized for thepurposes of paragraph 1.47 – the inletfrom and opening for the ductwork; and

(v) where the shaft contains a lift – thepassage of lift cables into a lift motorroom. Where the motor room is at thebottom of the shaft the opening shall be assmall as practicable

see para 3.19(c)

Diagram 3.3 Glazed screen separating protected shaft from corridoror lobby

fire resistance provisionfor protecting structureor not more than 60minutes

......

...

......

......

......

......

......

.

........

(a) With corridor (b) With lobby

corridor

protectedshaft

glazed screen

protectedshaft

glazed screen

lobby

Key

fire resistance of construction to be at least30 minutes (including doors)

fire resistance of glazingto be at least 30 minutes(including doors)

48

Fire doors3.22 A fire door shall have the performanceappropriate to the location given in Table 3.5and shall be fitted with an automatic self-closing device (other than those fire doors tocupboards and ducts, which are to be keptlocked shut when not in use).

Fire doors are classified by their performanceunder test to BS 476: Part 22 in respect ofintegrity expressed in minutes. A suffix (S) isadded for doors where smoke leakage atambient temperatures is to be restricted. Themethod of test exposure is from each side ofthe door separately, except in the case of liftdoors, which are tested from the landing sideonly.

3.23 A fire door shall only be held open by –

(a) a fusible link, provided that the provisionsof paragraph 3.25 are complied with where thedoor opening is provided for means of escape;

(b) an automatic release mechanism providedthat the door can also be closed manually anddoes not give access to –

(i) the only escape stairway serving abuilding or part of a building;

(ii) an escape stairway serving a buildingor compartment of Purpose Group 1 or 2;or

(iii) a firefighting stairway; or

(c) a door co-ordinator device which co-ordinates the closing sequence of rebateddouble leaf swing doors.

3.24 Unless shown to be satisfactory whentested as part of a fire door assembly, thehinges on which a fire door is hung shall bemade from material having a melting point of atleast 800�C

3.25 Where an opening is provided for, oropens onto, a means of escape and it isintended that the door shall be held open by afusible link, a second door having 30 minutesfire resistance shall be provided. This seconddoor shall be capable of closing the openingand be easily opened by hand.

Where two fire doors are fitted in the sameopening and each door is capable of closingthat opening, the total fire resistance may betaken as the sum of their individual fireresistance.

3.26 All fire doors, other than those listedbelow, shall be marked with an appropriate firesafety sign complying with BS 5499: Part 1:1990 indicating whether the door is –

(a) to be kept closed when not in use;

(b) to be kept locked shut when not in use; or

(c) held open by an automatic releasemechanism.

Signs shall be provided on both sides of thedoor except for doors to cupboards and serviceducts which shall be marked on the outsideonly.

The following fire doors do not require to bemarked –

(i) doors within dwellinghouses;

(ii) doors to and within flats and maisonettes;

(iii) bedroom doors in Purpose Group 2buildings; and

(iv) lift entrance doors.

49

Table 3.5 Fire doors

Location of door Minimum fire resistance of door in termsof integrity (minutes)(1)

1 In a compartment wall separating As for the wall in which the door is fitted,buildings but a minimum of 60

2 In a compartment wall not described in item 1 above –

(a) where it separates a flat or maisonette from a 30S(2)

space in common use

(b) where it forms part of a protected shaft forming 30S(2)

a stairway situated wholly or partly above theadjoining ground in a building of Purpose Group1(a), 2, 3 or 5

(c) enclosing a protected shaft forming a stairway Half the period of fire resistance of the wall in which itnot described in (b) above is fitted but 30 minimum and with suffix S

(d) not described in (a), (b) or (c) above As for the wall it is fitted in, but with suffix S if the door isused for progressive horizontal evacuation

3 In a compartment floor As for the floor in which it is fitted

4 In the wall of a protected shaft, not described in items2(b) or (c) above, which is –

(a) a protected stairway (other than one described in 30S(2)

item 9 below)

(b) a lift shaft or a service shaft 30

(c) any other shaft 30S(2)

5 In the enclosure of –

(a) a protected lobby or protected corridor to a 30S(2)

stairway

(b) any other protected corridor 20S(2)

6 In an external wall and giving access to an external 30escape route

7 Subdividing –

(a) corridors connecting alternative storey exits 20S(2)

(b) dead-end portions of corridors from the 20S(2)

remainder of the corridor

8 Any door –

(a) within a cavity barrier 30

(b) between a dwellinghouse and a garage 30

(c) in the enclosure to a communal area in sheltered 30S(2)

housing

9 Any door –

(a) forming part of the enclosures to a protected 20stair in a single family dwellinghouse

(b) within any other fire-resisting construction in 20a dwelling

Notes –

(1) To BS 476: Part 22 (or BS 476: Part 8 subject to paragraph 3.2).

(2) Unless pressurization techniques complying with BS 5588: Part 4 are used, these doors should also have a leakagerate not exceeding 3 m3m/hour (head and jambs only) when tested at 25 Pa under BS 476: Section 31.1.

50

Provision of cavity barriers3.27 To restrict the spread of smoke and flamethrough concealed spaces in the constructionof a building cavity barriers shall be provided –

(a) in a building of any purpose group –

(i) at the intersection of fire-resistingconstruction and an element containing acavity as shown in Diagram 3.4; and

(ii) as set out in Table 3.6 for theappropriate purpose group of the buildingand the specified locations.

[Note – alternative arrangements for items1, 3 and 4 are shown in Diagram 3.5 andfor item 2 in Diagram 3.6. Notes (3) and(4) to Table 3.6 are supported byDiagrams 3.7 and 3.8 respectively]; and

(b) in a building of Purpose Group 2, 3, 4, 5, 6or 7 – so that the maximum dimension of acavity, (other than one described in paragraph3.31 or 3.32) shall be not greater than thatgiven in Table 3.7 for the appropriate location ofthe cavity.

3.28 A cavity barrier shall not be used above acompartment wall to complete the line ofcompartmentation, i.e. a compartment wallshall be carried up to a compartment floor or toa roof.

Table 3.6 Provision of cavity barriers

Purpose group to whichthe provision applies

Item Cavity barriers to be provided3, 4, 5,

1a 1b & c 2 6 and 7

1 At the top of an external cavity wall and at the junction ✓ ✓ ✓ ✓

between an external cavity wall and a compartment wallthat separates buildings, except where the external cavitycomplies with Diagram 3.5

2 Above(1) the enclosures to a protected stairway in a N/A ✓ N/A N/Adwellinghouse of three or more storeys (see Diagram 3.6)(3)

3 At the junction between an external cavity wall and every ✓ N/A ✓ ✓

compartment floor and compartment wall, except wherethe external cavity wall complies with Diagram 3.5

4 At the junction between a cavity wall and every ✓ N/A ✓ ✓

compartment floor, compartment wall, or other wall or doorassembly which forms a fire-resisting barrier, except wherethe external cavity wall complies with Diagram 3.5

5 In a protected escape route, above(1) any fire resisting ✓ N/A ✓ ✓

construction which is not carried full storey height(2), or(in the case of a top storey) to the underside of the roofcovering(3)

51

Table 3.6 Provision of cavity barriers

Purpose group to whichthe provision applies

Item Cavity barriers to be provided3, 4, 5,

1a 1b & c 2 6 and 7

6 Above(1) any bedroom partitions which are not carried full N/A N/A ✓ N/Astorey height(2), or (in the case of a top storey) to theunderside of the roof covering(3)

7 Above(1) any corridor enclosures which are not carried full N/A N/A ✓ ✓

storey height(2), or (in the case of a top storey) to theunderside of the roof covering, where the corridor (which isnot a protected corridor) is subdivided to prevent fire orsmoke affecting two alternative escape routessimultaneously (see Section 1)(4)

8 To subdivide any cavity (including any roof space ) so that N/A N/A ✓ ✓

the distance between cavity barriers does not exceed thedimensions given in Table 3.7

9 Within the void behind the external face of rainscreen ✓ N/A ✓ N/Acladding at every floor level, and on the line ofcompartment walls abutting the external wall, of buildingswhich have a floor more than 20 m above ground level

Notes –

✓ Provision applies.

N/A Not applicable.

(1) Above and in the same plane as the element.

(2) Full storey height means to the underside of the structural floor above.

(3) The cavity barriers in items 2, 5 and 6 are not required where the cavity is enclosed on the lower side by a fire-resisting ceiling (as shown in Diagram 3.7) which extends throughout the building, compartment or separated part.

(4) The cavity barrier in item 7 is not required where the storey is subdivided by fire-resisting construction carried fullstorey height(2) and passing through the line of subdivision of the corridor (see Diagram 3.8), or where the cavity isenclosed on the lower side as described in Note (3) above.

Table 3.7 Maximum dimension of a cavity in Purpose Group 2, 3, 4, 5, 6and 7 buildings

Class of surface exposed in cavity(excluding surface of any pipe, Maximum dimension of

Location of cavity cable or conduit, or insulation to a cavity in anyany pipe) direction (m)

Between a roof and a Any 20ceiling

Any other cavity Class 0 or Class 1 20

A class other than Class 0 or 10Class 1

Notes –

Exceptions to these provisions are given in paragraphs 3.31 and 3.32.

52

Construction of cavity barriers

3.29 A cavity barrier shall be constructed toprovide fire resistance of not less than 30minutes in respect of integrity and 15 minutesin respect of insulation (see item 15 of Table3.1), however, a cavity barrier in a stud partitionor wall may be formed of –

(a) steel at least 0.5 mm thick;

(b) timber at least 38 mm thick;

(c) polyethylene sleeved mineral wool ormineral wool slab, in either case undercompression when installed in the cavity; or

(d) calcium silicate, cement based or gypsumbased boards at least 12.5 mm thick.

A cavity barrier may be formed by anyconstruction provided for another purpose ifthat construction meets the provisions for acavity barrier.

3.30 A cavity barrier shall be tightly fitted andfixed in position. Where this is not possible,e.g. in the case of a junction with slates orprofiled sheeting, the junction shall be fire-stopped in accordance with paragraphs 3.37 to3.39.

The fixing of a cavity barrier shall be such thatthe performance of the cavity barrier is unlikelyto be made ineffective by–

(a) the movement of the building due tosubsidence, shrinkage or thermal change andmovement of the external envelope due towind;

(b) the collapse in a fire of any service whichpenetrates it;

(c) the failure in a fire of its fixings orsupporting structure; and

(d) the failure in a fire of any material orconstruction which the cavity barrier abuts, e.g.if a cavity barrier is connected to a suspendedceiling, collapse of the ceiling should not causepremature failure of the cavity barrier.

Diagram 3.4 Cavity barriers at intersections

see para 3.27(a) wall with cavity

compartmentfloor

floor

cavitybarrier

alternatively carry wallup to underside of floor

suspended ceilingfire-resisting wall (butnot a compartment wall)

cavitybarrier

cavitybarrier

wall with cavity

cavitybarrier

fire-resisting door

fire-resisting wall (but not a wall requiredto be fire-resisting solelybecause it is aloadbearing wall)

fire-resisting wall (but not a wall requiredto be fire-resisting solelybecause it is aloadbearing wall)

wall with cavity

(a) Section (b) Section

(d) Plan(c) Plan

53

Diagram 3.5 Cavity walls excluded from provisions for cavity barriers

see para 3.27(a), 3.31(a) and Table 3.6 items 1.3 & 4

Section

close cavity attop of wall (unlesscavity is totallyfilled with insulation)

close cavity at topof opening

external cavity wall of two leaves ofbrick, block or concrete each at least75 mm thick – cavity width 100mm maximum

Combustible material shall not be placed inor exposed to the cavity except for –

(a) timber lintels, window or door frames or theends of timber joists;

(b) pipe, conduit or cable;

(c) d.p.c., flashing, cavity closer or wall tie;

(d) thermal insulating material; or

(e) a domestic meter cupboard provided that –there are no more than two cupboards perdwelling;the opening in the outer wall leaf is notmore than 800 x 500mm for eachcupboard; andthe inner leaf is not penetrated except bya sleeve not more than 80 x 80mm, which is fire stopped.

Note

opening

see para 3.27(a) and Table 3.6 item 2

(a) With cavity barrier(s) asrequired by Table 3.6

cavity barrier(s)in roof space

protectedstairway

fire-resistingenclosureto stairway

roof space

fire-resisting ceiling (seeDiagram 3.7)

protectedstairway

roof space

Diagram 3.6 Alternative arrangement of cavity barriers in roof space overa protected stairway in a dwellinghouse of three or morestoreys

(b) Alternative arrangement withfire-resisting ceiling

fire resistingenclosureto stairway

54

Cavities not requiring subdivision3.31 The provisions of paragraph 3.27 (b) shallnot apply to a cavity which is–

(a) in a masonry or concrete external cavitywall complying with Diagram 3.5;

(b) in a floor void or in a roof void where thecavity does not exceed 30 m in extent and isenclosed on its lower side by a fire-resistingceiling (complying with Diagram 3.7) whichextends throughout the building orcompartment;

(c) below a floor next to the ground where thecavity is not greater than 1 m in height or is notnormally accessible by people. However, thisshall not apply where there is any opening inthe floor such that it is possible for combustiblematerial to accumulate in the cavity (in thiscase cavity barriers and access for cleaningshall be provided);

(d) formed behind the external skin in rain-screen external wall construction, or by over-cladding an existing masonry or concreteexternal wall or an existing concrete roof,provided that the cavity does not containcombustible insulation and the provisions ofTable 3.6 Item 9 are complied with; and

(e) between double-skinned, profiled,insulated, roof sheeting provided that –

(i) the sheeting is a material of limitedcombustibility;

(ii) both surfaces of the insulation layerhave a surface spread of flameclassification not lower than Class 1; and

(iii) the insulation is in contact with theinner and outer skins of sheeting asshown in Diagram 3.9 (a).

3.32 Where the cavity is over an undividedroom which –

(a) exceeds the appropriate maximumdimension for a cavity in Table 3.7, cavitybarriers need only be provided on the line ofthe enclosing walls of that room or at 40 mcentres whichever is the lesser; or

(b) exceeds 40 m (in either direction on plan)cavity barriers need not be provided where –

(i) the room and the cavity together arecompartmented from the rest of thebuilding;

(ii) an automatic fire detection and alarmsystem complying with BS 5839: Part 1:1988 is fitted in the building;

(iii) the surface of the ceiling exposed inthe cavity is of Class 0 and the ceilingsupports and fixings in the cavity are ofnon-combustible construction;

(iv) the surface spread of flameclassification of any pipe insulation in thecavity is not lower than Class 1;

(v) any electrical wiring in the cavity is laidin metal trays or in metal conduit;

(vi) any other material in the cavity is amaterial of limited combustibility; and

(vii) where the cavity is used as a plenum– the recommendations of BS 5588: Part9: 1989 in relation to recirculating airdistribution systems are complied with.

see para 3.27(a), 3.31(b), Table 3.6 note(3) and Diag. 3.6

Diagram 3.7 Fire-resisting ceiling below a cavity

floor or roofconstruction

NoteThe ceiling shall –

(a) have at least 30 minutes fireresistance;

(b) be imperforate except for anopening described inparagraph 3.33;

(c) extend throughout the buildingor compartment; and

(d) not be demountable.

cavity

ceilingupper ceiling surface – Class 1

lower ceiling surface – Class 0

55

see para 3.31(e)

Diagram 3.9 Provision of cavity barriers in double-skinned profiledinsulated roof sheeting

insulation insulation

(a) Acceptable without cavity barrierswhere the insulation is in contactwith both skins of the sheeting

(b) Cavity barriers necessary

void

Diagram 3.8 Alternative arrangements for corridor enclousure

see para 3.27(a) and Table 3.6 note(4)

cavity barrier

Key

accommodation

ceiling void (cavity)

corridor

corridor

floor suspended ceiling

floor suspended ceiling

accommodation

ceiling void (cavity) cavity barrier

(a) Section showing use of cavity barriers above the corridorenclosure as required by Table 3.6

(b) Alternative arrangement plan showing subdivision of the storeyby fire-resisting construction [see Table 3.6, item 7 and note (4)]

F.D.

floor

accommodation

cavity barrier abovecorridor on line of subdivision

stair stair

the subdivision is carriedfull storey height andincludes subdivision of the corridora cavity barrier is used in the corridor ceiling void, overthe corridor subdivision

F.D.fire-resisting door

fire-resisting construction

Diagram 3.8 Alternative arrangements for corridor enclosure

56

Openings in cavity barriers3.33 There shall be no openings in a cavitybarrier other than those for–

(a) a fire door which has not less than 30minutes fire resistance and complies withparagraphs 3.22 to 3.26;

(b) the passage of a pipe which complies withparagraph 3.34;

(c) the passage of a cable, a conduit or traycontaining one or more cables;

(d) an opening fitted with a suitably mountedautomatic fire shutter; and

(e) a duct which (unless it is fire-resisting) isfitted with a suitably mounted automatic fireshutter where it passes through the cavitybarrier.

Pipes penetrating compartmentwalls, compartment floors,protected shafts and cavitybarriers3.34 Where a pipe passes through acompartment wall or a compartment floor(unless the pipe is within a protected shaft) orthrough a protected shaft or a cavity barrier itshall be–

(a) provided with a suitable proprietary sealingsystem which has been shown by test tomaintain the fire resistance of the wall, floor orcavity barrier; or

(b) where a proprietary sealing system is notused–

(i) of a diameter not more than therelevant nominal internal diameter given inTable 3.8, with the opening as small as ispracticable and fire-stopped around thepipe; or

(ii) of lead, aluminium, aluminium alloy,fibre-cement or PVC, having a maximuminternal diameter not more than 160 mmand be within a non-combustible sleeve[see Table 3.8 Note (1)] as shown inDiagram 3.10.

Note

The opening in the constructionto be as small as possible withfire-stopping between sleeve andconstruction.

see para 3.34(b)

not lessthan 1m

not lessthan 1m

fire-stopping sleeve to be a sliding fit

pipe

Diagram 3.10 Pipes penetrating compartment walls, compartment floors, protected shafts and cavity barriers

57

Table 3.8 Maximum nominal internal diameter of pipes passing throughcompartment walls, compartment floors, protected shafts andcavity barriers

Pipe material and maximum nominal internaldiameter (mm)

Situation Non- Lead, aluminium Anycombustible aluminium alloy, other

material(1) PVC(2), fibre-cement material

1 Construction (but not a wall 160 110 40separating buildings) enclosing aprotected shaft which is not astairway or a lift shaft

2 (a) A wall separating 160 160 (stack pipe)(3) 40dwellinghouses 110 (branch pipe)(3)

(b) A compartment wall orcompartment floor between flats

3 Any other situation 160 40 40

Notes –

(1) A non-combustible material (such as cast iron or steel) which if exposed to a temperature of 800�C, will not soften orfracture to the extent that flame or hot gas will pass through the wall of the pipe.

(2) PVC pipes complying with either BS 4514: 1983 or BS 5255:1989.

(3) These diameters are only in relation to pipes forming part of an above-ground drainage system which is enclosed asshown in Diagram 3.11. In other cases the maximum diameters against Situation 3 apply.

58

Ventilation ducts penetratingcompartment walls, compartment floors,protected shafts and cavity barriers3.35 Where a ventilation or air conditioningduct passes through a compartment wall orcompartment floor (unless it is within aprotected shaft) or through a protected shaft ora cavity barrier it shall comply with one of themethods for maintaining the fire resistance ofthe wall, floor or barrier given in BS 5588: Part9: 1989.

Flues and heating appliance ventilationducts penetrating compartment wallsand compartment floors3.36 Where a flue, a duct containing more thanone flue, or an appliance ventilation duct –

(a) passes through a compartment floor orcompartment wall; or

(b) is built into a compartment wall,

the walls enclosing the flue or duct shall have aperiod of fire resistance of not less than halfthat required for the compartment wall orcompartment floor and be of non-combustibleconstruction, as shown in Diagram 3.12.

see Table 3.8 note(3)

provide casing ifwall separatingdwellinghousesis penetrated by branchpipe at this storey

floor carried through toseal enclosure – providefire-stopping betweenstack pipe and floor

casing

enclosure

enclosure

roof space

intermediate floor

wall separatingdwellinghouses

fire-stopping

stack pipe

vent pipe

compartment floorcarried through toseal enclosure –provide fire-stoppingbetween stack pipeand floor

enclosure

enclosure

compartment floor

intermediate floor

fire stopping

stack pipe

casing

Intermediate floorcarried through toseal enclosure –provide fire-stoppingbetween stack pipeand floor

compartment wall

compartment wall

compartment floor

(a) Dwellinghouse with any number of storeys (b) Other buildings

Note

(1) The enclosure shall –

(a) be bounded by a compartment wall or floor,an outside wall, an intermediate floor or acasing [see specification at (2)];

(b) have internal surfaces (except framing members) of Class O;

(c) not have an access panel which opens into acirculation space or a bedroom; and

(d) be used only for drainage, water supply or ventpipes for a drainage system.

(2) The casing shall –

(a) be imperforate except for an opening for apipe or an access panel;

(b) not to be of sheet metal; and

(c) have (including any access panel) not lessthan 30 minutes fire resistance.

(3) The opening for a pipe, either in the structureor the casing, shall be as small as possibleand fire-stopped around the pipe.

Diagram 3.11 Enclosure for drainage or water supply pipes

59

Fire-stopping3.37 In addition to any other provision in thisTechnical Booklet for fire-stopping, fire-stoppingshall be provided at –

(a) all joints and imperfections of fit betweenelements which serve as a barrier to thepassage of fire; and

(b) all openings for pipes, ducts, cables,conduits or trays which pass through anyelement which serves as a barrier to thepassage of fire, and such openings shall be –

(i) as few in number as possible; and

(ii) as small as is practicable.

3.38 To prevent the displacement of fire-stopping it shall be supported by, or reinforcedwith, a material of limited combustibility –

(a) where it is a non-rigid material (unless ithas been shown by test not to require suchsupport or reinforcement); and

(b) in all locations where its unsupported spanis more than 100 mm.

3.39 In addition to proprietary fire-stopping andsealing systems, which have been shown bytest to be suitable, the following materials maybe suitable as fire-stopping in situationsappropriate to the particular material –

cement mortar; gypsum based plaster; cementor gypsum based vermiculite/perlite mixes;glass fibre, crushed rock, blast furnace slag orceramic based products (with or without resinbinders); and intumescent mastics.

see para 3.36

(a) Section of flue passingthrough a compartmentfloor

Note

In all cases flue walls shall have a fire resistance of at leastone half of that required for the compartment wall or compartmentfloor and be of non-combustible construction.

Diagram 3.12 Flues in compartment walls and compartment floors

compartmentfloor

compartmentwall

flue wall

compartmentwall

flue wall flue wall

(b) Plans of flues built intocompartment wall

*

flue

flue

flue

* * *

60

Car parks for light vehicles3.40 All materials used in the construction of abuilding, separated part of compartment usedfor car parking shall be non-combustible otherthan –

(a) a surface finish which meets the relevantprovisions of Sections 2 and 4 which –

(i) is applied to a floor or roof of the carpark; and

(ii) is applied within any adjoining building,separated part or compartment – to thestructure enclosing the car park;

(b) a fire door; and

(c) an attendant’s kiosk which does not exceed15 m2 in area.

Open-sided car parks3.41 A car park may be regarded as an open-sided car park for the purposes of Table 3.2[i.e. Purpose Group 7 (b) (i)] where, in additionto complying with paragraph 3.40 –

(a) it has no basement storeys;

(b) it is naturally ventilated by permanentopenings, at each car parking level, having anaggregate ventilation area of not less than 5%of the floor area at that level, with not less thanhalf that ventilation area equally divided in twoopposing walls and distributed to provideeffective cross-ventilation; and

(c) where the building is also used for anyother purpose – that part forming the car parkis a separated part.

Car parks which are not open-sided3.42 Where a car park does not comply withthe provisions of paragraph 3.41 it shall not beregarded as open-sided for the purposes ofTable 3.2 [i.e. it falls in Purpose Group 7 (b)(ii)]. However, there is a need for ventilation insuch a car park, therefore in addition to theprovisions of paragraph 3.40 it shall haveeither –

(a) natural ventilation at each storey –

(i) by permanent openings at each carparking level, having an aggregateventilation area of not less than 2.5% ofthe floor area at that level, with not lessthan half that ventilation area equallydivided in two opposing walls anddistributed to provide effective cross-ventilation; or

(ii) by suitable vents at ceiling level oneach car parking level having anaggregate area of permanent opening notless than 2.5% of the floor area and soarranged as to have a through flow of air;or

(b) a system of mechanical ventilation where –

(i) the system is independent of any otherventilation system and designed tooperate at 6 air changes per hour fornormal extraction and at 10 air changesper hour in a fire condition;

(ii) the system is designed to operate intwo parts, each capable of extracting 50%of the rates set out in (i) above anddesigned so that each part may operatesingly or simultaneously; each part of thesystem shall have an independent powersupply which will operate in the event offailure of the main supply;

(iii) extract points are arranged so that50% are at high level and 50% at lowlevel; and

(iv) the fans are rated to run at 300°C fornot less than 60 minutes, and theductwork and fixings are constructed ofmaterials having a melting point of not lessthan 800°C.

61

4.1 This Section contains provisions relating tothe design and construction of –

(a) external walls – in order that the risk ofignition from an external source, the spread offlame over the external surface and the spreadof fire from one building to another arerestricted; and

(b) roofs – in order that the risk of spread offlame and of fire penetration from an externalsource are restricted.

Construction of external walls

4.2 The external walls of a building areelements of structure and other than thoseareas which may be unprotected (asdetermined in accordance with paragraphs 4.8to 4.10) shall have the appropriate period of fireresistance given in Section 3.

4.3 The external surface of a wall shall meetthe requirements given in Table 4.1 relevant tothe height of the building and the distancebetween the building and the relevantboundary. The provisions of Table 4.1 areillustrated in Diagram 4.1.

In the case of the external wall being of“rainscreen” construction (i.e. an outer claddingwith a drained and ventilated cavity behind) thesurface of the outer cladding which faces thecavity shall also meet the relevantrequirements of Table 4.1.

Section 4 – External fire spread

Table 4.1 Provisions for external surfaces of walls

Maximum height of Distance of wall from any point on the relevant boundarybuilding

(m) Less than 1 m 1 m or more

Less than 20 Class 0 (a) Purpose Group 5 – no requirement other than asdescribed in Note 1

(b) All other purpose groups – no requirement

20 or more Class 0 (a) Surfaces 20 m or more above ground level –Class 0

(b) Surfaces less than 20 m above ground level –see Note 2

Notes –

(1) In a Purpose Group 5 building of more than one storey any part of a wall which is less than 10 m above –

(a) the ground;

(b) a roof to which the public have access; or

(c) any other part of the building to which the public have access,

shall have an index of performance (I) of not more than 20 when tested to BS 476: Part 6: 1981 or 1989, or betimber cladding at least 9 mm thick.

(2) Surfaces less than 20 m above the ground may be of any material which has an index of peformance (I) of not morethan 20 when tested to BS 476: Part 6: 1981 or 1989, or be timber cladding at least 9 mm thick.

see para 4.3

Diagram 4.1 Provisions for external surfaces of walls

any Purpose Group(other than 5)

*

Maximum height of building – less than 20m

*

Purpose Group 5

roof to whichthe public have access

Class O

no provisionin respect ofthe boundaryindicated

index (I) notmore than 20,or timbercladding at least9mm thick

lessthan1m

lessthan1m

1m ormore

lessthan1m

lessthan1m

lessthan10m

1m ormore

1m or

1m ormore

lessthan10m

lessthan10m

any Purpose Group

lessthan20m

lessthan1m

lessthan1m

1m ormore

1m ormore

lessthan20m

relevant boundary

Maximum height of building – 20m or more

Key

62

63

4.4 Where a building has a storey the floor ofwhich is 20 m or more above ground level anymaterials used for supporting cladding and anyinsulation material incorporated within the wallconstruction (other than a masonry cavity wallcomplying with Diagram 3.4) shall be a materialof limited combustibility. [Advice on theincorporation of thermal insulation in such wallsis given in Building Research EstablishmentReport – Fire performance of external thermalinsulation for walls of multi-storey buildings(BR135: 1988).]

Portal frames4.5 Frequently, the provisions of Section 3 donot require the portal frames of a single storeybuilding to have fire resistance except wherethe column members of those frames arewithin, or support, an external wall, which underparagraph 4.2, is required to have fireresistance. Where this occurs both the columnand rafter members shall have fire resistance,as the moment-resisting connections mean theportal frame acts as a single element. However,in the case of a steel portal frame which hasbeen designed in accordance with the methodset out in Fire and steel construction: TheBehaviour of Steel Portal Frames in BoundaryConditions: 1990 (2nd Edition), only thosemembers within or supporting an external wallrequiring fire resistance, need have fireresistance.

Space separation – External walls4.6 Protection against the external spread offire from one building to another is related to –

(i) the distance between a building and each ofits relevant boundaries (see paragraph 4.7);and

(ii) the extent of the unprotected area in theside of the building which faces that boundary.

The basic provisions are outlined in paragraph4.11 and methods of meeting those provisionsare given in paragraphs 4.12 to 4.16.

The provisions are based on a number ofassumptions, and whilst some of these maydiffer from the circumstances of a particularcase, together they enable a reasonablestandard of space separation to be achieved.

The provisions limit the extent of openings andother unprotected areas in the sides of abuilding (including areas with a combustiblesurface) which would not give adequateprotection against the external spread of firefrom one building to another.

The assumptions for establishing spaceseparation are –

(a) that the fire will involve a completecompartment but will not spread to othercompartments;

(b) that the intensity of a fire is related to theuse of the building and will be moderated by asprinkler system where it is provided;

(c) that a building, which has an identicalelevation, is located on the opposite side of,and at the same distance from, the relevantboundary; and

(d) that radiation from that part of the externalwall, which has the fire resistance required bySection 3, is discounted unless its externalsurface is combustible as described inparagraph 4.8.

Boundaries4.7 For a boundary to be a relevant boundary itshall coincide with, be parallel to or be at anangle of not more than 80° to the side of thebuilding (see Diagram 4.2).

A relevant boundary may be –

(a) the actual boundary of the premises onwhich the building is located;

(b) the centre line of a road, river, canal orrailway which adjoins the actual boundary; or

(c) a notional boundary established where twoor more buildings (one of which is of PurposeGroup 1, 2 or 5) are to share the same site. Anotional boundary shall be assumed so thatboth buildings comply with the spaceseparation distances required by this Section.

Where a notional boundary is to be establishedand one of the buildings is an existing building,that building shall be treated as if it were a newbuilding.

64

Unprotected areas in external walls4.8 Any part of an external wall which has lessfire resistance than that required by Section 3shall be considered to be an unprotected area.

Where an external wall has the appropriate fireresistance but has a combustible material morethan 1 mm thick as its external surface, thatwall shall be considered to be an unprotectedarea amounting to half the actual area of thecombustible material. Such an unprotectedarea shall be considered to be centrally locatedon the actual area of combustible material asshown in Diagram 4.3.

Any part of the external wall of a protectedstairway shall be discounted when calculatingunprotected areas. (However, Section 1 andSection 5 contain provisions relating to therelationship between the external walls ofprotected stairways and the unprotected areasof other parts of the building.)

Small unprotected areas may be discountedwhere they occur in an otherwise protectedarea of wall, provided that they do not exceedthe areas and comply with the minimumspacing shown in Diagram 4.4.

see para 4.7

Diagram 4.2 Relevant boundaries

minimum separationdistance for existingbuilding

boundary not more than80� to side C

not more than 80�

boundarycoincideswith side D

notional boundaryfor side B

*boundary parallel to side A

centre line of road, river, canal or railway

Note

Notional boundary is only established where one or both of the buildings is of Purpose Group 1, 2 or 5.*

existingbuilding proposed buildingB

A

D

C

see para 4.8

area of wall to becounted asunprotected area= 0.5 a x b, centredon actual areaof combustiblesurface material

area of fire-resistingwall without combustiblesurface material

b

area of fire-resisting wallwith combustiblematerial = a x b

Diagram 4.3 Combustible materialon external walls

a

65

4.9 An external wall situated within 1 m of anypoint on its relevant boundary shall have nounprotected areas other than those shown inDiagram 4.4.

4.10 An external wall situated 1 m or morefrom any point on its relevant boundary mayhave unprotected areas provided that their totalarea does not exceed that given by the mostfavourable calculation method given inparagraphs 4.11 to 4.16. Where a building isuncompartmented any part of an external wallwhich is more than 30 m above ground levelmay be discounted in the calculation.

Diagram 4.4 Unprotected areas which may be discounted

see para 4.8, 4.9 and 4.14

compartmentfloor

compartmentwall

an unprotected area of not more than 1m2

which may consist of two or more smallerareas amounting to not more than 1m2

within an area of 1m x 1m

the external wall of a protected stairway

Dimensional restrictions

4m minimum distance

1.5m minimum distance

dimension not restricted

Key

an unprotected area of not more than 0.1m2

66

Provisions for and calculation of spaceseparation and unprotected areas4.11 A building shall be separated from itsrelevant boundaries by at least half thedistance at which the total thermal radiationintensity received from all unprotected areas inthe external walls would be 12.6 kW/m2 (in stillair) assuming the radiation intensity at eachunprotected area is –

(a) 84 kW/m2 where the building is of PurposeGroup 1, 2, 3, 5 or 7 (b); or

(b) 168 kW/m2 where the building is of anyother purpose group.

Where a building is compartmented eachcompartment shall be calculated separately.

Where a building or compartment is fittedthroughout with a sprinkler system complyingwith the relevant provisions of BS 5306: Part 2:1990 for the appropriate occupancy, thethermal radiation intensities in (a) and (b) andthe distances calculated using the methodsgiven in paragraphs 4.13 to 4.16 may behalved subject to there being a minimumdistance of 1 m.

4.12 Building Research Establishment Report –External fire spread: building separation andboundary distances (BR187: 1991) gives themethod by which the thermal radiation intensityshall be calculated for paragraph 4.11. It alsogives detailed explanations, with workedexamples, of Method 3 (paragraph 4.15) andMethod 4 (paragraph 4.16).

Method 1 (Small residential buildings)4.13 This method may only be used forbuildings in Purpose Groups 1 and 2 (b) whichdo not exceed three storeys in height and arenot more than 24 m in length. The maximumtotal area of unprotected areas in the side of abuilding shall not exceed that given in Table 4.2for the relevant minimum distance between thatside and its boundary.

Method 2 (Small buildings andcompartments)4.14 This method may be used for buildingsand compartments of any purpose group whichdo not exceed 10 m in height [this height limitdoes not apply to buildings of Purpose Group 7(b)]. The maximum total percentage ofunprotected area in the side of a building shallnot exceed that given in Table 4.3 for theappropriate purpose group and minimumdistance between that side and its relevantboundary. When calculating the unprotectedarea any area which complies with paragraph4.8 and Diagram 4.4 may be discounted.

Table 4.2 Unprotected areas insmall residentialbuildings (Method 1)

Minimum distancebetween side Maximum total area

of building and of unprotectedrelevant boundary (m) areas (m2)

1 5.6

2 12

3 18

4 24

5 30

6 No limit

67

Method 3 (Enclosing rectangle) –4.15 This method may be used for buildingsand compartments of any purpose group. Abuilding or compartment shall be so situatedthat no point on its relevant boundary is –

(a) between the relevant plane of referenceand the side of the building; and

(b) closer to the relevant plane of referencethan that given in Table 4.4 for the appropriatepurpose group, dimensions of enclosingrectangle and unprotected area percentage.

A plane of reference is a vertical plane whichtouches the side, or some part of the side, of abuilding or compartment but which (however,far extended) does not pass within the structure(excluding balconies, copings and similarprojections) of that building or compartment.The relevant plane of reference shall bechosen to give the least separation distancebetween it and the relevant boundary. Normally,it will be best for the plane of reference to beparallel to the relevant boundary.

The enclosing rectangle is the rectangle, of theleast width and height given in Table 4.4, onthe relevant plane of reference, which will –

(i) enclose all the outer edges of theunprotected areas in the external wall of thebuilding or compartment (other than any whichis at an angle of 80� or more to the plane ofreference). The outer edges shall be projectedto the plane of reference by lines perpendicularto such plane; and

(ii) have two horizontal sides.

The total unprotected area is found by addingthe areas, as projected on the plane ofreference, of all unprotected areas.

The unprotected percentage is calculatedfrom –

total unprotectedareaunprotected = ————————— x 100

percentage enclosing rectanglearea

The minimum distance from the plane ofreference to the relevant boundary is given inTable 4.4, and where the unprotectedpercentage is between the values given in theTable the distance may be obtained by linearinterpolation.

Table 4.3 Unprotected areas in small buildings and compartments (Method 2)

Minimum distance between side of building andrelevant boundary (m)

Purpose groups Maximum total percentageof unprotected area

(%)1, 2, 3 and 5 4, 6 and 7 *

N/A 1 4

1 2 8

2.5 5 20

5 10 40

7.5 15 60

10 20 80

12.5 25 100

Notes –

* In the case of a car park in Purpose Group 7(b) the distances given for Purpose Groups 1, 2, 3 and 5 may be used.

N/A = not applicable.

Intermediate values may be obtained by interpolation.

68

Table 4.4 Permitted unprotected percentages in relation to enclosing rectangles(Method 3)

Distance from relevant boundary for unprotected percentage not exceedingWidth of

enclosing 20% 30% 40% 50% 60% 70% 80% 90% 100%rectangle

(m) Minimum boundary distance (m) – figures in brackets are for Purpose Groups 1, 2, 3, 5 and 7(b)

Enclosing rectangle 3 m high

3 1.0(1.0) 1.5(1.0) 2.0(1.0) 2.0(1.5) 2.5(1.5) 2.5(1.5) 2.5(2.0) 3.0(2.0) 3.0(2.0)6 1.5(1.0) 2.0(1.0) 2.5(1.5) 3.0(2.0) 3.0(2.0) 3.5(2.0) 3.5(2.5) 4.0(2.5) 4.0(3.0)9 1.5(1.0) 2.5(1.0) 3.0(1.5) 3.5(2.0) 4.0(2.5) 4.0(2.5) 4.5(3.0) 5.0(3.0) 5.0(3.5)

12 2.0(1.0) 2.5(1.5) 3.0(2.0) 3.5(2.0) 4.0(2.5) 4.5(3.0) 5.0(3.0) 5.5(3.5) 5.5(3.5)15 2.0(1.0) 2.5(1.5) 3.5(2.0) 4.0(2.5) 4.5(2.5) 5.0(3.0) 5.5(3.5) 6.0(3.5) 6.0(4.0)18 2.0(1.0) 2.5(1.5) 3.5(2.0) 4.0(2.5) 5.0(2.5) 5.0(3.0) 6.0(3.5) 6.5(4.0) 6.5(4.0)

21 2.0(1.0) 3.0(1.5) 3.5(2.0) 4.5(2.5) 5.0(3.0) 5.5(3.0) 6.0(3.5) 6.5(4.0) 7.0(4.5)24 2.0(1.0) 3.0(1.5) 3.5(2.0) 4.5(2.5) 5.0(3.0) 5.5(3.5) 6.0(3.5) 7.0(4.0) 7.5(4.5)27 2.0(1.0) 3.0(1.5) 4.0(2.0) 4.5(2.5) 5.5(3.0) 6.0(3.5) 6.5(4.0) 7.0(4.0) 7.5(4.5)

30 2.0(1.0) 3.0(1.5) 4.0(2.0) 4.5(2.5) 5.5(3.0) 6.0(3.5) 6.5(4.0) 7.5(4.0) 8.0(4.5)40 2.0(1.0) 3.0(1.5) 4.0(2.0) 5.0(2.5) 5.5(3.0) 6.5(3.5) 7.0(4.0) 8.0(4.0) 8.5(5.0)50 2.0(1.0) 3.0(1.5) 4.0(2.0) 5.0(2.5) 6.0(3.0) 6.5(3.5) 7.5(4.0) 8.0(4.0) 9.0(5.0)

60 2.0(1.0) 3.0(1.5) 4.0(2.0) 5.0(2.5) 6.0(3.0) 7.0(3.5) 7.5(4.0) 8.5(4.0) 9.5(5.0)80 2.0(1.0) 3.0(1.5) 4.0(2.0) 5.0(2.5) 6.0(3.0) 7.0(3.5) 8.0(4.0) 9.0(4.0) 9.5(5.0)

No limit 2.0(1.0) 3.0(1.5) 4.0(2.0) 5.0(2.5) 6.0(3.0) 7.0(3.5) 8.0(4.0) 9.0(4.0) 10.0(5.0)

Enclosing rectangle 6 m high

3 1.5(1.0) 2.0(1.0) 2.5(1.5) 3.0(2.0) 3.0(2.0) 3.5(2.0) 3.5(2.5) 4.0(2.5) 4.0(3.0)6 2.0(1.0) 3.0(1.5) 3.5(2.0) 4.0(2.5) 4.5(3.0) 5.0(3.0) 5.5(3.5) 5.5(4.0) 6.0(4.0)9 2.5(1.0) 3.5(2.0) 4.5(2.5) 5.0(3.0) 5.5(3.5) 6.0(4.0) 6.0(4.5) 7.0(4.5) 7.0(5.0)

12 3.0(1.5) 4.0(2.5) 5.0(3.0) 5.5(3.5) 6.5(4.0) 7.0(4.5) 7.5(5.0) 8.0(5.0) 8.5(5.5)15 3.0(1.5) 4.5(2.5) 5.5(3.0) 6.0(4.0) 7.0(4.5) 7.5(5.0) 8.0(5.5) 9.0(5.5) 9.0(6.0)18 3.5(1.5) 4.5(2.5) 5.5(3.5) 6.5(4.0) 7.5(4.5) 8.0(5.0) 9.0(5.5) 9.5(6.0) 10.0(6.5)

21 3.5(1.5) 5.0(2.5) 6.0(3.5) 7.0(4.0) 8.0(5.0) 9.0(5.5) 9.5(6.0) 10.0(6.5) 10.5(7.0)24 3.5(1.5) 5.0(2.5) 6.0(3.5) 7.0(4.5) 8.5(5.0) 9.5(5.5) 10.0(6.0) 10.5(7.0) 11.0(7.0)27 3.5(1.5) 5.0(2.5) 6.5(3.5) 7.5(4.5) 8.5(5.0) 9.5(6.0) 10.5(6.5) 11.0(7.0) 12.0(7.5)

30 3.5(1.5) 5.0(2.5) 6.5(3.5) 8.0(4.5) 9.0(5.0) 10.0(6.0) 11.0(6.5) 12.0(7.0) 12.5(8.0)40 3.5(1.5) 5.5(2.5) 7.0(3.5) 8.5(4.5) 10.0(5.5) 11.0(6.5) 12.0(7.0) 13.0(8.0) 14.0(8.5)50 3.5(1.5) 5.5(2.5) 7.5(3.5) 9.0(4.5) 10.5(5.5) 11.5(6.5) 13.0(7.5) 14.0(8.0) 15.0(9.0)

60 3.5(1.5) 5.5(2.5) 7.5(3.5) 9.5(5.0) 11.0(5.5) 12.0(6.5) 13.5(7.5) 15.0(8.5) 16.0(9.5)80 3.5(1.5) 6.0(2.5) 7.5(3.5) 9.5(5.0) 11.5(6.0) 13.0(7.0) 14.5(7.5) 16.0(8.5) 17.5(9.5)100 3.5(1.5) 6.0(2.5) 8.0(3.5) 10.0(5.0) 12.0(6.0) 13.5(7.0) 15.0(8.0) 16.5(8.5) 18.0(10.0)

120 3.5(1.5) 6.0(2.5) 8.0(3.5) 10.0(5.0) 12.0(6.0) 14.0(7.0) 15.5(8.0) 17.0(8.5) 19.0(10.0)No limit 3.5(1.5) 6.0(2.5) 8.0(3.5) 10.0(5.0) 12.0(6.0) 14.0(7.0) 16.0(8.0) 18.0(8.5) 19.0(10.0)

69

Table 4.4 Permitted unprotected percentages in relation to enclosing rectangles(Method 3)

Distance from relevant boundary for unprotected percentage not exceedingWidth of

enclosing 20% 30% 40% 50% 60% 70% 80% 90% 100%rectangle

(m) Minimum boundary distance (m) – figures in brackets are for Purpose Groups 1, 2, 3, 5 and 7(b)

Enclosing rectangle 9 m high

3 1.5(1.0) 2.5(1.0) 3.0(1.5) 3.5(2.0) 4.0(2.5) 4.0(2.5) 4.5(3.0) 5.0(3.0) 5.0(3.5)6 2.5(1.0) 3.5(2.0) 4.5(2.5) 5.0(3.0) 5.5(3.5) 6.0(4.0) 6.5(4.5) 7.0(4.5) 7.0(5.0)9 3.5(1.5) 4.5(2.5) 5.5(3.5) 6.0(4.0) 6.5(4.5) 7.5(5.0) 8.0(5.5) 8.5(5.5) 9.0(6.0)

12 3.5(1.5) 5.0(3.0) 6.0(3.5) 7.0(4.5) 7.5(5.0) 8.5(5.5) 9.0(6.0) 9.5(6.5) 10.5(7.0)15 4.0(2.0) 5.5(3.0) 6.5(4.0) 7.5(5.0) 8.5(5.5) 9.5(6.0) 10.0(6.5) 11.0(7.0) 11.5(7.5)18 4.5(2.0) 6.0(3.5) 7.0(4.5) 8.5(5.0) 9.5(6.0) 10.0(6.5) 11.0(7.0) 12.0(8.0) 12.5(8.5)

21 4.5(2.0) 6.5(3.5) 7.5(4.5) 9.0(5.5) 10.0(6.5) 11.0(7.0) 12.0(7.5) 13.0(8.5) 13.5(9.0)24 5.0(2.0) 6.5(3.5) 8.0(5.0) 9.5(5.5) 11.0(6.5) 12.0(7.5) 13.0(8.0) 13.5(9.0) 14.5(9.5)27 5.0(2.0) 7.0(3.5) 8.5(5.0) 10.0(6.0) 11.5(7.0) 12.5(7.5) 13.5(8.5) 14.5(9.5) 15.0(10.0)

30 5.0(2.0) 7.0(3.5) 9.0(5.0) 10.5(6.0) 12.0(7.0) 13.0(8.0) 14.0(9.0) 15.0(9.5) 16.0(10.5)40 5.5(2.0) 7.5(3.5) 9.5(5.5) 11.5(6.5) 13.0(7.5) 14.5(8.5) 15.5(9.5) 17.0(10.5) 17.5(11.5)50 5.5(2.0) 8.0(4.0) 10.0(5.5) 12.5(6.5) 14.0(8.0) 15.5(9.0) 17.0(10.0) 18.5(11.5) 19.5(12.5)

60 5.5(2.0) 8.0(4.0) 11.0(5.5) 13.0(7.0) 15.0(8.0) 16.5(9.5) 18.0(11.0) 19.5(11.5) 21.0(13.0)80 5.5(2.0) 8.5(4.0) 11.5(5.5) 13.5(7.0) 16.0(8.5) 17.5(10.0) 19.5(11.5) 21.5(12.5) 23.0(13.5)100 5.5(2.0) 8.5(4.0) 11.5(5.5) 14.5(7.0) 16.5(8.5) 18.5(10.0) 21.0(11.5) 22.5(12.5) 24.5(14.5)

120 5.5(2.0) 8.5(4.0) 11.5(5.5) 14.5(7.0) 17.0(8.5) 19.5(10.0) 21.5(11.5) 23.5(12.5) 26.0(14.5)No Limit 5.5(2.0) 8.5(4.0) 11.5(5.5) 15.0(7.0) 17.5(8.5) 20.0(10.5) 22.5(12.0) 24.5(12.5) 27.0(15.0)

Enclosing rectangle 12 m high

3 2.0(1.0) 2.5(1.5) 3.0(2.0) 3.5(2.0) 4.0(2.5) 4.5(3.0) 5.0(3.0) 5.5(3.5) 5.5(3.5)6 3.0(1.5) 4.0(2.5) 5.0(3.0) 5.5(3.5) 6.5(4.0) 7.0(4.5) 7.5(5.0) 8.0(5.0) 8.5(5.5)9 3.5(1.5) 5.0(3.0) 6.0(3.5) 7.0(4.5) 7.5(5.0) 8.5(5.5) 9.0(6.0) 9.5(6.5) 10.5(7.0)

12 4.5(1.5) 6.0(3.5) 7.0(4.5) 8.0(5.0) 9.0(6.0) 9.5(6.5) 11.0(7.0) 11.5(7.5) 12.0(8.0)15 5.0(2.0) 6.5(3.5) 8.0(5.0) 9.0(5.5) 10.0(6.5) 11.0(7.0) 12.0(8.0) 13.0(8.5) 13.5(9.0)18 5.0(2.5) 7.0(4.0) 8.5(5.0) 10.0(6.0) 11.0(7.0) 12.0(7.5) 13.0(8.5) 14.0(9.0) 14.5(10.0)

21 5.5(2.5) 7.5(4.0) 9.0(5.5) 10.5(6.5) 12.0(7.5) 13.0(8.5) 14.0(9.0) 15.0(10.0) 16.0(10.5)24 6.0(2.5) 8.0(4.5) 9.5(6.0) 11.5(7.0) 12.5(8.0) 14.0(8.5) 15.0(9.5) 16.0(10.5) 16.5(11.5)27 6.0(2.5) 8.0(4.5) 10.5(6.0) 12.0(7.0) 13.5(8.0) 14.5(9.0) 16.0(10.5) 17.0(11.0) 17.5(12.0)

30 6.5(2.5) 8.5(4.5) 10.5(6.5) 12.5(7.5) 14.0(8.5) 15.0(9.5) 16.5(10.5) 17.5(11.5) 18.5(12.5)40 6.5(2.5) 9.5(5.0) 12.0(6.5) 14.0(8.0) 15.5(9.5) 17.5(10.5) 18.5(12.0) 20.0(13.0) 21.0(14.0)50 7.0(2.5) 10.0(5.0) 13.0(7.0) 15.0(8.5) 17.0(10.0) 19.0(11.0) 20.5(13.0) 23.0(14.0) 23.0(15.0)

60 7.0(2.5) 10.5(5.0) 13.5(7.0) 16.0(9.0) 18.0(10.5) 20.0(12.0) 21.5(13.5) 23.5(14.5) 25.0(16.0)80 7.0(2.5) 11.0(5.0) 14.5(7.0) 17.0(9.0) 19.5(11.0) 21.5(13.0) 23.5(14.5) 26.0(16.0) 27.5(17.0)100 7.5(2.5) 11.5(5.0) 15.0(7.5) 18.0(9.5) 21.0(11.5) 23.0(13.5) 25.5(15.0) 28.0(16.5) 30.0(18.0)

120 7.5(2.5) 11.5(5.0) 15.0(7.5) 18.5(9.5) 22.0(11.5) 24.0(13.5) 27.0(15.0) 29.5(17.0) 31.5(18.5)No limit 7.5(2.5) 12.0(5.0) 15.5(7.5) 19.0(9.5) 22.5(12.0) 25.0(14.0) 28.0(15.5) 30.5(17.0) 34.0(19.0)

70

Table 4.4 Permitted unprotected percentages in relation to enclosing rectangles(Method 3)

Distance from relevant boundary for unprotected percentage not exceedingWidth of

enclosing 20% 30% 40% 50% 60% 70% 80% 90% 100%rectangle

(m) Minimum boundary distance (m) – figures in brackets are for Purpose Groups 1, 2, 3, 5 and 7(b)

Enclosing rectangle 15 m high

3 2.0(1.0) 2.5(1.5) 3.5(2.0) 4.0(2.5) 4.5(2.5) 5.0(3.0) 5.5(3.5) 6.0(3.5) 6.0(4.0)6 3.0(1.5) 4.5(2.5) 5.5(3.0) 6.0(4.0) 7.0(4.5) 7.5(5.0) 8.0(5.5) 9.0(5.5) 9.0(6.0)9 4.0(2.0) 5.5(3.0) 6.5(4.0) 7.5(5.0) 8.5(5.5) 9.5(6.0) 10.0(6.5) 11.0(7.0) 11.5(7.5)

12 5.0(2.0) 6.5(3.5) 8.0(5.0) 9.0(5.5) 10.0(6.5) 11.0(7.0) 12.0(8.0) 13.0(8.5) 13.5(9.0)15 5.5(2.0) 7.0(4.0) 9.0(5.5) 10.0(6.5) 11.5(7.0) 12.5(8.0) 13.5(9.0) 14.5(9.5) 15.0(10.0)18 6.0(2.5) 8.0(4.5) 9.5(6.0) 11.0(7.0) 12.5(8.0) 13.5(8.5) 14.5(9.5) 15.5(10.5) 16.5(11.0)

21 6.5(2.5) 8.5(5.0) 10.5(6.5) 12.0(7.5) 13.5(8.5) 14.5(9.5) 16.0(10.5) 16.5(11.0) 17.5(12.0)24 6.5(3.0) 9.0(5.0) 11.0(6.5) 13.0(8.0) 14.5(9.0) 15.5(10.0) 17.0(11.0) 18.0(12.0) 19.0(13.0)27 7.0(3.0) 9.5(5.5) 11.5(7.0) 13.5(8.5) 15.0(9.5) 16.5(10.5) 18.0(11.5) 19.0(12.5) 20.0(13.5)

30 7.5(3.0) 10.0(5.5) 12.0(7.5) 14.0(8.5) 16.0(10.0) 17.0(11.0) 18.5(12.0) 20.0(13.5) 21.0(14.0)40 8.0(3.0) 11.0(6.0) 13.5(8.0) 16.0(9.5) 18.0(11.0) 19.5(12.5) 21.0(13.5) 22.5(15.0) 23.5(16.0)50 8.5(3.5) 12.0(6.0) 15.0(8.5) 17.5(10.0) 19.5(12.0) 21.5(13.5) 23.0(15.0) 25.0(16.5) 26.0(17.5)

60 8.5(3.5) 12.5(6.5) 15.5(8.5) 18.0(10.5) 21.0(12.5) 23.5(14.0) 25.0(15.5) 27.0(17.0) 28.0(18.0)80 9.0(3.5) 13.5(6.5) 17.0(9.0) 20.0(11.0) 23.0(13.5) 25.5(15.0) 28.0(17.0) 30.0(18.5) 31.5(20.0)100 9.0(3.5) 14.0(6.5) 18.0(9.0) 21.5(11.5) 24.5(14.0) 27.5(16.0) 30.0(18.0) 32.5(19.5) 34.5(21.5)

120 9.0(3.5) 14.0(6.5) 18.5(9.0) 22.5(11.5) 25.5(14.0) 28.5(16.5) 31.5(18.5) 34.5(20.5) 37.0(22.5)No limit 9.0(3.5) 14.5(6.5) 19.0(9.0) 23.0(12.0) 27.0(14.5) 30.0(17.0) 34.0(19.0) 36.0(21.0) 39.0(23.0)

Enclosing rectangle 18 m high

3 2.0(1.0) 2.5(1.5) 3.5(2.0) 4.0(2.5) 5.0(2.5) 5.0(3.0) 6.0(3.5) 6.5(4.0) 6.5(4.0)6 3.5(1.5) 4.5(2.5) 5.5(3.5) 6.5(4.0) 7.5(4.5) 8.0(5.0) 9.0(5.5) 9.5(6.0) 10.0(6.5)9 4.5(2.0) 6.0(3.5) 7.0(4.5) 8.5(5.0) 9.5(6.0) 10.0(6.5) 11.0(7.0) 12.0(8.0) 12.5(8.5)

12 5.0(2.5) 7.0(4.0) 8.5(5.0) 10.0(6.0) 11.0(7.0) 12.0(7.5) 13.0(8.5) 14.0(9.0) 14.5(10.0)15 6.0(2.5) 8.0(4.5) 9.5(6.0) 11.0(7.0) 12.5(8.0) 13.5(8.5) 14.5(9.5) 15.5(10.5) 16.5(11.0)18 6.5(2.5) 8.5(5.0) 11.0(6.5) 12.0(7.5) 13.5(8.5) 14.5(9.5) 16.0(11.0) 17.0(11.5) 18.0(13.0)

21 7.0(3.0) 9.5(5.5) 11.5(7.0) 13.0(8.0) 14.5(9.5) 16.0(10.5) 17.0(11.5) 18.0(12.5) 19.5(13.0)24 7.5(3.0) 10.0(5.5) 12.0(7.5) 14.0(8.5) 15.5(10.0) 16.5(11.0) 18.5(12.0) 19.5(13.0) 20.5(14.0)27 8.0(3.5) 10.5(6.0) 12.5(8.0) 14.5(9.0) 16.5(10.5) 17.5(11.5) 19.5(12.5) 20.5(13.5) 21.5(14.5)

30 8.0(3.5) 11.0(6.5) 13.5(8.0) 15.5(9.5) 17.0(11.0) 18.5(12.0) 20.5(13.5) 21.5(14.5) 22.5(15.5)40 9.0(4.0) 12.0(7.0) 15.0(9.0) 17.5(11.0) 19.5(12.0) 21.5(13.5) 23.5(15.0) 25.0(16.5) 26.0(17.5)50 9.5(4.0) 13.0(7.0) 16.5(9.5) 19.0(11.5) 21.5(13.0) 23.5(15.0) 26.0(16.5) 27.5(18.0) 29.0(19.0)

60 10.0(4.0) 14.0(7.5) 17.5(10.0) 20.5(12.0) 23.0(14.0) 26.0(16.0) 27.5(17.5) 29.5(19.5) 31.0(20.5)80 10.0(4.0) 15.0(7.5) 19.0(10.0) 22.5(13.0) 26.0(15.0) 28.5(17.0) 31.0(19.0) 33.5(21.0) 35.0(22.5)100 10.0(4.0) 16.0(7.5) 20.5(10.0) 24.0(13.5) 28.0(16.0) 31.0(18.0) 33.5(20.5) 36.0(22.5) 38.5(24.0)

120 10.0(4.0) 16.5(7.5) 21.0(10.0) 25.5(14.0) 29.5(16.5) 32.5(19.0) 35.5(21.0) 39.0(23.5) 41.5(25.5)No limit 10.0(4.0) 17.0(8.0) 22.0(10.0) 26.5(14.0) 30.5(17.0) 34.0(19.5) 37.0(22.0) 41.0(24.0) 43.5(26.5)

71

Table 4.4 Permitted unprotected percentages in relation to enclosing rectangles(Method 3)

Distance from relevant boundary for unprotected percentage not exceedingWidth of

enclosing 20% 30% 40% 50% 60% 70% 80% 90% 100%rectangle

(m) Minimum boundary distance (m) – figures in brackets are for Purpose Groups 1, 2, 3, 5 and 7(b)

Enclosing rectangle 21 m high

3 2.0(1.0) 3.0(1.5) 3.5(2.0) 4.5(2.5) 5.0(3.0) 5.5(3.0) 6.0(3.5) 6.5(4.0) 7.0(4.5)6 3.5(1.5) 5.0(2.5) 6.0(3.5) 7.0(4.0) 8.0(5.0) 9.0(5.5) 9.5(6.0) 10.0(6.5) 10.5(7.0)9 4.5(2.0) 6.5(3.5) 7.5(4.5) 9.0(5.5) 10.0(6.5) 11.0(7.0) 12.0(7.5) 13.0(8.5) 13.5(9.0)

12 5.5(2.5) 7.5(4.0) 9.0(5.5) 10.5(6.5) 12.0(7.5) 13.0(8.5) 14.0(9.0) 15.0(10.0) 16.0(10.5)15 6.5(2.5) 8.5(5.0) 10.5(6.5) 12.0(7.5) 13.5(8.5) 14.5(9.5) 16.0(10.5) 16.5(11.0) 17.5(12.0)18 7.0(3.0) 9.5(5.5) 11.5(7.0) 13.0(8.0) 14.5(9.5) 16.0(10.5) 17.0(11.5) 18.0(12.5) 19.5(13.0)

21 7.5(3.0) 10.0(6.0) 12.5(7.5) 14.0(9.0) 15.5(10.0) 17.0(11.0) 18.5(12.5) 20.0(13.5) 21.0(14.0)24 8.0(3.5) 10.5(6.0) 13.0(8.0) 15.0(9.5) 16.5(10.5) 18.0(12.0) 20.0(13.0) 21.0(14.0) 22.0(15.0)27 8.5(3.5) 11.5(6.5) 14.0(8.5) 16.0(10.0) 18.0(11.5) 19.0(13.0) 21.0(14.0) 22.5(15.0) 23.5(16.0)

30 9.0(4.0) 12.0(7.0) 14.5(9.0) 16.5(10.5) 18.5(12.0) 20.5(13.0) 22.0(14.5) 23.5(16.0) 25.0(16.5)40 10.0(4.5) 13.5(7.5) 16.5(10.0) 19.0(12.0) 21.5(13.5) 23.0(15.0) 25.5(16.5) 27.0(18.0) 28.5(19.0)50 11.0(4.5) 14.5(8.0) 18.0(11.0) 21.0(13.0) 23.5(14.5) 25.5(16.5) 28.0(18.0) 30.0(20.0) 31.5(21.0)

60 11.5(4.5) 15.5(8.5) 19.5(11.5) 22.5(13.5) 25.5(15.5) 28.0(17.5) 30.5(19.5) 32.5(21.0) 33.5(22.5)80 12.0(4.5) 17.0(8.5) 21.0(12.0) 25.0(14.5) 28.5(17.0) 31.5(19.0) 34.0(21.0) 36.5(23.5) 38.5(25.0)100 12.0(4.5) 18.0(9.0) 22.5(12.0) 27.0(15.5) 31.0(18.0) 34.5(20.5) 37.0(22.5) 40.0(25.0) 42.0(27.0)

120 12.0(4.5) 18.5(9.0) 23.5(12.0) 28.5(16.0) 32.5(18.5) 36.5(21.5) 39.5(23.5) 43.0(26.5) 45.5(28.5)No limit 12.0(4.5) 19.0(9.0) 25.0(12.0) 29.5(16.0) 34.5(19.0) 38.0(22.0) 41.5(25.0) 45.5(26.5) 48.0(29.5)

Enclosing rectangle 24 m high

3 2.0(1.0) 3.0(1.5) 3.5(2.0) 4.5(2.5) 5.0(3.0) 5.5(3.5) 6.0(3.5) 7.0(4.0) 7.5(4.5)6 3.5(1.5) 5.0(2.5) 6.0(3.5) 7.0(4.5) 8.5(5.0) 9.5(5.5) 10.0(6.0) 10.5(7.0) 11.0(7.0)9 5.0(2.0) 6.5(3.5) 8.0(5.0) 9.5(5.5) 11.0(6.5) 12.0(7.5) 13.0(8.0) 13.5(9.0) 14.5(9.5)

12 6.0(2.5) 8.0(4.5) 9.5(6.0) 11.5(7.0) 12.5(8.0) 14.0(8.5) 15.0(9.5) 16.0(10.5) 16.5(11.5)15 6.5(3.0) 9.0(5.0) 11.0(6.5) 13.0(8.0) 14.5(9.0) 15.5(10.0) 17.0(11.0) 18.0(12.0) 19.0(13.0)18 7.5(3.0) 10.0(5.5) 12.0(7.5) 14.0(8.5) 15.5(10.0) 16.5(11.0) 18.5(12.0) 19.5(13.0) 20.5(14.0)

21 8.0(3.5) 10.5(6.0) 13.0(8.0) 15.0(9.5) 16.5(10.5) 18.0(12.0) 20.0(13.0) 21.0(14.0) 22.0(15.0)24 8.5(3.5) 11.5(6.5) 14.0(8.5) 16.0(10.0) 18.0(11.5) 19.5(12.5) 21.0(14.0) 22.5(15.0) 24.0(16.0)27 9.0(4.0) 12.5(7.0) 15.0(9.0) 17.0(11.0) 19.0(12.5) 20.5(13.5) 22.5(15.0) 24.0(16.0) 25.5(17.0)

30 9.5(4.0) 13.0(7.5) 15.5(9.5) 18.0(11.5) 20.0(13.0) 21.5(14.0) 23.5(15.5) 25.0(17.0) 26.5(18.0)40 11.0(4.5) 14.5(8.5) 18.0(11.0) 20.5(13.0) 23.0(14.5) 25.0(16.0) 27.5(18.0) 29.0(19.0) 30.5(20.5)50 12.0(5.0) 16.0(9.0) 19.5(12.0) 22.5(14.0) 25.5(16.0) 27.5(17.5) 30.0(19.5) 32.0(21.0) 33.5(22.5)

60 12.5(5.0) 17.0(9.5) 21.0(12.5) 24.5(15.0) 27.5(17.0) 30.0(19.0) 32.5(21.0) 35.0(23.0) 36.5(24.5)80 13.5(5.0) 18.5(10.0) 23.5(13.5) 27.5(16.5) 31.0(18.5) 34.5(21.0) 37.0(23.5) 39.5(25.5) 41.5(27.5)100 13.5(5.0) 20.0(10.0) 25.0(13.5) 29.5(17.0) 33.5(20.0) 37.0(22.5) 40.0(25.0) 43.0(27.5) 45.5(29.5)

120 13.5(5.5) 20.5(10.0) 26.5(13.5) 31.0(17.5) 36.0(20.5) 39.5(23.5) 43.0(26.5) 46.5(29.0) 49.0(31.0)No limit 13.5(5.5) 21.0(10.0) 27.5(13.5) 32.5(18.0) 37.5(21.0) 42.0(24.0) 45.5(27.5) 49.5(30.0) 52.0(32.5)

72

Table 4.4 Permitted unprotected percentages in relation to enclosing rectangles(Method 3)

Distance from relevant boundary for unprotected percentage not exceedingWidth of

enclosing 20% 30% 40% 50% 60% 70% 80% 90% 100%rectangle

(m) Minimum boundary distance (m) – figures in brackets are for Purpose Groups 1, 2, 3, 5 and 7(b)

Enclosing rectangle 27 m high

3 2.0(1.0) 3.0(1.5) 4.0(2.0) 4.5(2.5) 5.5(3.0) 6.0(3.5) 6.5(4.0) 7.0(4.0) 7.5(4.5)6 3.5(1.5) 5.0(2.5) 6.5(3.5) 7.5(4.5) 8.5(5.0) 9.5(6.0) 10.5(6.5) 11.0(7.0) 12.0(7.5)9 5.0(2.0) 7.0(3.5) 8.5(5.0) 10.0(6.0) 11.5(7.0) 12.5(7.5) 13.5(8.5) 14.5(9.5) 15.0(10.0)

12 6.0(2.5) 8.0(4.5) 10.5(6.0) 12.0(7.0) 13.5(8.0) 14.5(9.0) 16.0(10.5) 17.0(11.0) 17.5(12.0)15 7.0(3.0) 9.5(5.5) 11.5(7.0) 13.5(8.5) 15.0(9.5) 16.5(10.5) 18.0(11.5) 19.0(12.5) 20.0(13.5)18 8.0(3.5) 10.5(6.0) 12.5(8.0) 14.5(9.0) 16.5(10.5) 17.5(11.5) 19.5(12.5) 20.5(13.5) 21.5(14.5)

21 8.5(3.5) 11.5(6.5) 14.0(8.5) 16.0(10.0) 18.0(11.5) 19.0(13.0) 21.0(14.0) 22.5(15.0) 23.5(16.0)24 9.0(3.5) 12.5(7.0) 15.0(9.0) 17.0(11.0) 19.0(12.5) 20.5(13.5) 22.5(15.0) 24.0(16.0) 25.5(17.0)27 10.0(4.0) 13.0(7.5) 16.0(10.0) 18.0(11.5) 20.0(13.0) 22.0(14.0) 24.0(16.0) 25.5(17.0) 27.0(18.0)

30 10.0(4.0) 13.5(8.0) 17.0(10.0) 19.0(12.0) 21.0(13.5) 23.0(15.0) 25.0(17.0) 26.5(18.0) 28.0(19.0)40 11.5(5.0) 15.5(9.0) 19.0(11.5) 22.0(14.0) 24.5(15.5) 26.5(17.5) 29.0(19.0) 30.5(20.5) 32.5(22.0)50 12.5(5.5) 17.0(9.5) 21.0(12.5) 24.0(15.0) 27.0(17.0) 29.5(19.0) 32.0(21.0) 34.5(22.5) 36.0(24.0)

60 13.5(5.5) 18.5(10.5) 22.5(13.5) 26.5(16.0) 29.5(18.5) 32.0(20.5) 35.0(22.5) 37.0(24.5) 39.0(26.5)80 14.5(6.0) 20.5(11.0) 25.0(14.5) 29.5(17.5) 33.0(20.5) 36.5(22.5) 39.5(25.0) 42.0(27.5) 44.0(29.5)100 15.5(6.0) 21.5(11.0) 27.0(15.5) 32.0(19.0) 36.5(21.5) 40.5(24.5) 43.0(27.0) 46.5(30.0) 48.5(32.0)

120 15.5(6.0) 22.5(11.5) 28.5(15.5) 34.0(19.5) 39.0(22.5) 43.0(26.0) 46.5(28.5) 50.5(32.0) 53.0(34.0)No limit 15.5(6.0) 23.5(11.5) 29.5(15.5) 35.0(20.0) 40.5(23.5) 44.5(27.0) 48.5(29.5) 52.0(33.0) 55.5(35.0)

73

Method 4 (Aggregate notional area)4.16 This method can be used for a building orcompartment of any purpose group. A buildingor compartment shall be so situated that theaggregate notional area of the unprotectedareas in the side of the building orcompartment does not exceed, in the case of –

(a) a building or compartment of PurposeGroup 1, 2, 3, 5 or 7 (b) – 210 m2; or

(b) a building or compartment of any otherpurpose group – 90 m2,

when calculated from any vertical datum on itsrelevant boundary.

The aggregate notional area is the aggregateof the areas of unprotected area in the side ofthe building or compartment, each suchunprotected area being multiplied by the Factorgiven in Table 4.5 relative to the distance theunprotected area is from the vertical datum.

A vertical datum is a vertical line of unlimitedheight at any point on the relevant boundaryand the datum line is the line joining the verticaldatum to the nearest point on the side of thebuilding or compartment.

When calculating the aggregate notional areano account shall be taken of any unprotectedarea which is –

(i) screened from the vertical datum by anypart of an external wall which is not anunprotected area;

(ii) outside a horizontal area centred on thevertical datum, having a radius of 50 m andextending 90� on either side of the datum line;

(iii) facing away from the vertical datum; or

(iv) making an angle of less than 10� with aline drawn from it to the vertical datum.

Canopies4.17 The high degree of ventilation and heatdissipation achieved by open sided canopiesmeans that the space separation required byparagraph 4.11 may be onerous.

The provisions of paragraph 4.11 shall notapply to –

(a) a single storey, open sided canopy,constructed of non-combustible materials,which is not less than 1 m from its relevantboundaries; and

(b) a covered way, covered yard or a carport,which is open on two or more sides and is notmore than 40 m2 in area.

The provisions regarding roof coverings androof separation distances shall apply (seeparagraph 4.18 to 4.20).

Table 4.5 Multiplication factors fordetermining aggregatenotional areas (Method 4)

Distance of unprotected areafrom vertical datum (m)

Factor

Not less than Less than

1.0 1.2 801.2 1.8 401.8 2.7 202.7 4.3 104.3 6.0 46.0 8.5 28.5 12.0 112.0 18.5 0.518.5 27.5 0.2527.5 50.0 0.150.0 No limit 0

74

Roofs

Roof covering designations4.18 The designation of a roof covering inrespect of external fire exposure shall bedetermined by testing in accordance with BS476: Part 3: 1958 and expressed by two lettersin the range A to D. The notional designationsof some generic roof coverings are given inTable 4.6. Where a thermoplastic materialcannot be given a designation when tested toBS 476: Part 3: 1958 it may be used as arooflight provided that it can be classified underparagraph 2.5 and is used in accordance withparagraph 4.20. Where unwired glass, not lessthan 4 mm thick, is used in a rooflight it shallbe regarded as having an AA designation.

Table 4.6 Notional designations of roof coverings

Part 1 – Pitched roofs covered with slates or tiles

Covering material Supporting structure Designation

1 Natural slates Timber rafters with or without AA2 Fibre reinforced underfelt, sarking, boarding,

cement sheets wood wool slabs, compressed3 Clay tiles straw slabs, plywood, wood4 Concrete tiles chipboard or fibre insulating

board

5 Bitumen felt strip Timber rafters and boarding, BBslates Type 2E, with plywood, wood wool slabs,underlayer of bitumen wood chipboard or fibrefelt Type 2B insulating board

6 Strip slates of Timber rafters and boarding, CCbitumen felt plywood, wood wool slabs,Class 1 or 2 compressed straw slabs, wood

chipboard or fibre insulatingboard

Notes –

Any reference in this Table to bitumen feltof a specified type is a reference tobitumen felt as so designated in BS 747: 1977 (1986).

75

Table 4.6 Notional designations of roof coverings

Part II – Pitched roofs covered with self-supporting sheets

Details of covering Supporting DesignationstructureMaterial Construction

1 Profiled sheets of – Single skin without Structure of AAunderlay or with timber, steel

(i) galvanised steel; underlay of – or concrete

(ii) aluminium; (i) plasterboard;

(iii) fibre reinforced (ii) fibrecement; or insulating

board; or(iv) prepainted (coil

coated) steel or (iii) wood woolaluminium with a slabPVC or PVF2

coating

2 Profiled sheets of – Double skin without Structure of AAinterlayer or with timber, steel

(i) galvanised steel; interlayer of – or concrete

(ii) aluminium; (i) resin-bondedglass fibre;

(iii) fibre reinforcedcement; or (ii) mineral wool

slab;

(iv) prepainted (coilcoated) steel or (iii) polystyrene; oraluminium with aPVC or PVF2 (iv) polyurethanecoating

76

Table 4.6 Notional designations of roof coverings

Part III – Pitched or flat roofs covered with fully supported material

Details of covering Designation

Covering material Supporting structure

1 Aluminium sheet Timber joists and – AA*

2 Copper sheet (i) tongued and groovedboarding; or

3 Zinc sheet (ii) plain edged boarding

4 Lead sheetSteel or timber joists with AA

5 Mastic asphalt deck of –

6 Vitreous enamelled (i) wood wool slab;steel sheet (ii) compressed straw slab;

(iii) wood chipboard;7 Lead/tin alloy (iv) fibre insulating board; or

coated steel sheet (v) 9.5 mm plywood

8 Zinc/aluminium alloy Concrete or clay pot slab (cast AAalloy coated steel in situ or precast), or non-sheet combustible deck of steel,

aluminium or fibre reinforced cement9 Pre-painted (coil (with or without insulation)

coated) steel sheetincluding liquid-applied PVC coatings

Notes –

* Lead sheet supported by timber joists and plainedge boarding shall be deemed to be of designation BA.

Part IV – Flat roofs covered with bitumen felt

A flat roof comprising a covering of bitumen felt shall (irrespective of the felt specification) be deemed to be ofdesignation AA if the felt is laid on a deck constructed of any of the materials prescribed in the Table in Part V andhas a surface finish of –

(a) bitumen bedded stone chippings covering the whole surface to a depth of not less than 12.5 mm;

(b) bitumen bedded tiles of a non-combustible material;

(c) sand and cement screed; or

(d) macadam

77

Table 4.6 Notional designations of roof coverings

Part V – Pitched roofs covered with bitumen felt

Details of felt Details of deckProfiled Profiledfibre aluminiumreinforced (single orcement or double skin) Concrete

Deck of steel deck without or clayType of Type of Deck of Deck of screeded (single or overlay pot slab

Number of layers upper under- 6mm plywood compressed wood double skin) or with (cast inlayer layer(s) 12.5mm wood or straw slab wool slab without overlay of situ of

flax chipboard, overlay or fibre precast)16mm (finished) with overlay insulatingT & G boarding or of fibre board19mm (finished) insulatingplain edged boarding board

two or three layers 1 Type 1E Type 1B CC AC AC AC AC ABbuilt up in (minimumaccordance with mass 13kg/CP 144: Part 3: 10 m2)1970

2 Type 2E Type 1B BB AB AB AB AB AB(minimummass 13kg/10 m2)

3 Type 2E Type 2B AB AB AB AB AB AB

4 Type 3E Type 3B or BC AC AB AB AB AB3G

Notes –

Any reference in this Table to bitumenfelt of a specified type is a referenceto bitumen felt as so designatedin BS 747: 1977 (1986).

78

Space separation roofs4.19 The minimum distance from any part of aroof, other than a plastic rooflight, to a relevantboundary (see paragraph 4.7) shall not be lessthan that given in Table 4.7 for the relevantdesignation of roof covering. The boundaryformed by the compartment wall separatingsemi-detached dwellinghouses shall bedisregarded for the purposes of this paragraph.

Table 4.7 Limitations on roof coverings

Minimum distance from any point onrelevant boundary

Designation of covering ofroof or part of roof Less than Not less Not less Not less

6m than 6m than 12 m than 20 m

AA, AB or AC ✓ ✓ ✓ ✓

BA, BB or BC X ✓ ✓ ✓

CA, CB or CC X ✓ (1) ✓ (2) ✓

AD, BD or CD X ✓ (1) ✓ (2) ✓ (2)

DA, DB, DC or DD X X X ✓ (1)

Thatch or wood shingles, if performance X ✓ (1) ✓ (2) ✓ (2)

under BS 476: Part 3: 1958 cannot be established

Notes –

✓ Acceptable.

X Not acceptable.

(1) (a) Not acceptable on any of the following buildings –

(i) a dwellinghouse in a terrace of three or more dwellinghouses;

(ii) a building of Purpose Group 6 or 7 of any size; and

(iii) a building of any other purpose group greater than 1500 m3

(b) Acceptable on other buildings only where that part of the roof is –

(i) not more than 3 m2 in area;

(ii) not less than 1.5 m from any similar part; and

(iii) the roof covering between any such parts is a material of limited combustibility.

(2) Not acceptable on any of the buildings listed under Note (1)(a) above.

79

Table 4.8 Plastic rooflights – Limitations on use and boundary distance

Minimum distance (m) from anypoint on relevant boundary to

rooflight with an externalMinimum classification Space which rooflight surface classification of

on lower surface (1) can serveAD, BD, CA, CB, CC, CD DA, DB,

TP(a) or TP(b) DC orDD

1 TP(a) rigid Any space except a 6(2) 6(3) 20protected stairway

2 Class 3 or TP(b)(a) Balcony, verandah, 6 6 20

carport, covered wayor loading bay whichhas at least onelonger side whollyor permanently open

(b) Detached swimmingpool

(c) Conservatory, garageor outbuilding, witha maximum floor areaof 40 m2

(d) Circulation space(4) 6(3) 6(3) 20(3)

(except a protected stairway)

(e) Room(4)

Notes –

(1) As required by paragraph 2.12.

(2) No limit in the case of any space described in items 2(a), (b) and (c).

(3) The rooflight shall also comply with Diagram 4.5.

(4) Single skin rooflight only, in the case of non-thermoplastic materials.

For the purposes of this paragraph and Table4.8 a rigid thermoplastic rooflight, made frompolycarbonate or unplasticised PVC, whichachieves a Class 1 classification for surfacespread of flame (see paragraph 2.4) shall beregarded as having an AA designation.

4.20 Where a roof incorporates a plasticrooflight, which is not designated AA, AB, AC,BA, BB or BC, the minimum distance from thatrooflight to a relevant boundary shall not beless than that given in Table 4.8 for theappropriate classification of the rooflight andthe space over which it is located.

80

Diagram 4.5 Limitation onareas and spacing ofcertain thermoplasticrooflights

see Table 4.8 note (3)

rooflight *max. area 5m2

3m minimum betweenany two rooflightsin any direction

rooflight *max. area 5m2

Note –

* Or group of rooflightsamounting to not morethan 5m2 .

(1) Surrounding roof coveringto be a material of limitedcombustibility for at least3m distance.

81

5.1 This section contains provisions to ensurethat there is –

(a) sufficient means of access to and within abuilding for firefighting personnel to effectrescue and fight fire;

(b) sufficient facilities to assist firefighters intheir tasks;

(c) adequate means of venting smoke from afire in a basement; and

(d) adequate external access to enablefirefighting appliances to be brought near to abuilding for effective use.

Firefighting shafts5.2 A shopping complex shall be provided withfirefighting shafts in accordance with therecommendations of BS 5588: Part 10: 1991Section 3. Any other building shall be providedwith a firefighting shaft or shafts, to serve allstoreys, where it has –

(a) a storey more than 20 m above fire brigadeaccess level;

(b) a storey (other than one which is an opensided car park) 600 m2 or more in area at aheight of 7.5 m or more above fire brigadeaccess level;

(c) a storey more than 10 m below fire brigadeaccess level; or

(d) two or more basement storeys any of whichis 900 m2 or more in area.

However, a firefighting shaft provided under (a)or (b) need not serve a basement storey unless(c) or (d) applies and similarly a firefightingshaft provided under (c) or (d) need not servean upper storey unless (a) or (b) applies.

Diagram 5.1 illustrates the provisions of thisparagraph.

5.3 Where a building is to be provided withfirefighting shafts the minimum number (subjectto paragraph 5.4) shall be –

(a) where a building is fitted throughout with anautomatic sprinkler system complying with BS5306: Part 2: 1990 – as given in Table 5.1 forthe appropriate floor area; or

(b) where a building is not fitted throughoutwith such a sprinkler system – at least one forevery 900 m2, (or part thereof) of floor area ofthe largest storey given in paragraph 5.2 (a) to(d) as appropriate.

Table 5.1 Minimum number offirefighting shafts in abuilding fitted with asprinkler system

Floor area ofthe largest Minimum number of

storey firefighting shafts(m2)

Less than 900 1

900 to 2000 2

Over 2000 2 plus 1 for every 1500m2

or part thereof of floor area

5.4 Firefighting shafts shall be located so thatevery part of every storey (other than firebrigade access level) is not more than 60 mfrom the entrance to a firefighting shaft,measured on a route suitable for laying a firehose. Where the internal layout is unknownevery part of every such storey shall be notmore than 40 m, in a direct line, from theentrance to a firefighting shaft.

Section 5 – Facilities and access for theFire Brigade

82

Diagram 5.1 Provision of firefighting shafts

firefightingshaft

see para 5.2

firefightingshaft

firefightingshaft

firefightingshaft

fire brigade *access level

more than20m

more than10m

storey 600m2 or morein area

more than7.5m

Case (a) Case (b)

Case (c) Case (d)

fire brigade *access level

two or more basement storeys anyof which 900m2 or more in area

Note

* When measuring the height to an upper storey the highest level at which the Fire Brigadecan gain access shall be used and similarly when measuring the depth of a basementstorey the lowest level shall be used.

(1) In cases (a) and (c) the firefighting shaft shall include a firefighting lift.

fire brigade *access level

fire brigade *access level

83

5.5 Firefighting shafts shall be designed andconstructed in accordance with therecommendations of BS 5588: Part 5: 1991Sections 2 and 4.

Where a building falls within paragraph 5.2 (a)or (c) all firefighting shafts shall have afirefighting lift complying with therecommendations of BS 5588: Part 5: 1991Section 3.

Fire mains5.6 A firefighting shaft shall be provided with –

(a) a wet fire main where it has a storey morethan 60 m above fire brigade access level; or

(b) a wet or a dry fire main in any other case.

5.7 Fire mains shall be located in thefirefighting lobbies of firefighting shafts andshall have an outlet connection and valve atevery level other than at fire brigade accesslevel.

5.8 The design and construction of a fire mainshall be in accordance with the relevantrecommendations of BS 5306: Part 1: 1976(1988).

Venting of heat and smoke frombasements5.9 Venting facilities, connected directly to theexternal air, shall be provided from everybasement storey other than –

(a) a basement in a building of Purpose Group1(b) or (c);

(b) a basement storey which –

(i) has a floor area not more than 200 m2;or

(ii) has a floor not more than 3 m belowthe lowest adjacent ground level;

(c) a basement storey used for car parking andventilated in accordance with paragraph 3.42;and

(d) a basement storey or that part of abasement storey used as a strong room.

Natural venting5.10 A basement storey may be ventilated bysmoke outlets which shall –

(a) be sited at ceiling level within the spacethey serve;

(b) have an aggregate free are of not less2.5% of the floor area of the space they serve;

(c) be distributed as evenly as possible aroundthe perimeter of the building;

(d) be located so that they do not adverselyaffect any escape route from the building; and

(e) have a sign stating “smoke outlet frombasement” fixed adjacent to each externaloutlet point.

The smoke outlets from a place of special firerisk shall be separate from the smoke outletsfrom other areas.

5.11 Smoke outlets may discharge by meansof windows, stall-board risers or pavementlights which can be opened or knocked outprovided such covers are readily accessible tothe Fire Brigade.

Shafts enclosing smoke outlets shall be ofsmoke tight non-combustible construction andhave the same period of fire resistance as thatfor elements of structure in the basementstorey served.

Shafts from different parts of the samebasement storey, or from different basementstoreys, shall be separated by smoke tight non-combustible fire-resisting construction.

Mechanical venting5.12 A basement may be ventilated by amechanical air extraction system provided –

(a) the basement has a sprinkler systemcomplying with BS 5306: Part 2: 1990; and

(b) the air extraction system has a capacity notless than 10 air changes per hour and iscapable of operating at a temperature of 400�Cfor not less than 60 minutes.

The air extraction system shall come intooperation automatically on the activation ofeither –

(i) the sprinkler system; or

(ii) the fire detection and alarm system in thebasement where this system complies withBS 5839: Part 1: 1988, of at least L3 standard.

84

Vehicle access5.13 The provisions for vehicle access arerelated to whether or not the building has a firemain or mains and, where it does not, to thesize and height of the building. Where abuilding –

(a) does not have a fire main and is –

(i) less than 2000 m2 in area and theheight to the top storey is less than 9 m –access for a pump appliance shall beprovided to within 45 m of the building; or

[Note – the Building Regulations cannotimpose requirements for work to be donebeyond the boundary of the premises.]

(ii) other than as described in (i) – accessshall be provided in accordance with Table5.2;

(b) has dry fire mains – access for a pumpingappliance shall be provided to within 18 m, andwithin sight of, each fire main inlet connectionpoint; and

(c) has wet fire mains – access for a pumpingappliance shall be provided to within 18 m, andwithin sight of the emergency replenishmentinlet of the tank serving each fire main.

In every elevation to which the fire brigadeaccess is provided there shall be a door, notless than 750 mm wide, giving access to theinterior of the building. Where fire mains areprovided a door shall give access to each firemain.

Vehicle access routes and vehicularhardstandings areas5.14 A vehicle access route and vehicularhardstanding area shall be designed andconstructed to the standards given in Table 5.3and, in the case of those for high reachappliances, the dimensions shown in Diagram5.2.

Where the height of the top storey of a buildingis more than 9 m above the level of theadjoining ground the vehicle access route andthe vehicular hardstanding area shall besuitable for a high reach appliance. For lowerbuildings a vehicle access route shall besuitable for a pump appliance.

5.15 Turning facilities shall be provided in adead-end vehicle access route which is is morethan 20 m in length.

Vehicular hardstanding areas shall be as levelas possible and shall not exceed a gradient of1 in 12.

Table 5.2 Fire brigade vehicle access to buildings not fitted with fire mains

Height to topArea of building storey(1) Provide vehicle access to Type of appliance

(m2) (m)

Up to 2000 Up to 9 See paragraph 5.13(a) PumpOver 9 15% of perimeter(2) High reach

2000-8000 Up to 9 15% of perimeter(2) PumpOver 9 50% of perimeter(2) High reach

8000-16000 Up to 9 50% of perimeter(2) PumpOver 9 50% of perimeter(2) High reach

16000-24000 Up to 9 75% of perimeter(2) PumpOver 9 75% of perimeter(2) High reach

Over 24000 Up to 9 100% of perimeter(2) PumpOver 9 100% of perimeter(2) High reach

Notes –

(1) For Purpose Group 7(a) buildings the height shall be measured to the mean roof level.

(2) The perimeter is the aggregate plan perimeter found by vertical projection onto a horizontal ground plane excludingwalls separating buildings.

85

Table 5.3 Vehicle access routes

Minimum Minimum Minimum Minimumwidth width turning turning Minimum Minimum

Appliance of road of circle circle clearance carryingtype between gateways between between height (m) capacity

kerbs (m) (m) kerbs (m) walls (m) (tonnes)

Pump 3.7 3.1 16.8 19.2 3.7 12.5

High reach 3.7 3.1 26.0 29.0 4.0 17.0

Diagram 5.2 Relationship between a building and a vehicle access routeor a vehicular hardstanding area for a high reach appliance

see para 5.14

overhead obstruction to beavoided in this zone

C

B

A obstruction

vehicle hardstanding area

face of building at ground level or verticalplane of projecting upper storey

Note

* The hardstanding may extend closer to the building but any suchextension shall not be considered as a vehicle hardstanding area.

Dimensions

A maximum distance* to near edge of vehiclehardstanding area

B minimum distance to farthest edge of vehiclehardstanding area

C minimum width of unobstructed space

Type of appliance

Hydraulicplatform (m)

2.0

7.5

9.7

Turntableladder (m)

4.9

10.0

10.0

86

6.1 The provisions of this Section shall applywhen using Sections 1 to 5 of this TechnicalBooklet.

Purpose groups6.2 As many of the provisions in this TechnicalBooklet are related to the use of a building orcompartment it is necessary to classify eachbuilding and compartment, according to its use,into a purpose group.

A building may have a single use or it mayhave many uses. Sub-paragraphs (b) and (c)describe the circumstances where it isappropriate to treat a different use as apurpose group in its own right. (Note that theprovisions of paragraph 3.11 requirecompartmentation between different purposegroups.)

Every building and compartment shall beclassified according to its use, or intended use,into the most appropriate of those purposegroups given in Table 6.1 and –

(a) where the use of a building or compartmentwill vary from time to time, it shall be classifiedas the purpose group to which the more ormost onerous provisions in Section 3 apply;

(b) where a building or compartment has oneor more uses which are not ancillary to themain use of that building or compartment, eachportion given over to a separate use shall beclassified separately; and

(c) where the building or compartment has oneor more uses which are ancillary to the mainuse of that building or compartment, eachportion given over to an ancillary use shall beclassified separately when –

(i) it is a flat or maisonette;

(ii) in a Purpose Group 4 building orcompartment – it is storage occupyingmore than one third of the total floor areaof the building or compartment; or

(iii) in a building of any other purposegroup – it is a use [other than in (i) and (ii)]occupying more than one fifth of the totalfloor area of the building or compartment.

Section 6 – Common provisions

87

Table 6.1 Classification of purpose groups

Purpose for which the building or compartment of aTitle Group building is intended to be used

Residential*+ 1(a) Flat or maisonette(Dwellings)

1(b) Dwellinghouse which contains a habitable storey with a floor level which is more than4.5 m above ground level

1(c) Dwellinghouse which does not contain a habitable storey with a floor level which is morethan 4.5 m above ground level

Residential 2(a) Hospital, nursing home, home for old people or for children, school or other similar(Institutional) establishment used as living accommodation or for the treatment, care or maintenance

of people suffering from illness or mental or physical disability or handicap, place ofdetention, where such people sleep on the premises

(Other) 2(b) Hotel, boarding house, residential college, hall of residence, hostel, house in multipleoccupation, and any other residential purpose not described above

Office 3 Offices or premises used for the purpose of administration, clerical work (includingwriting, book keeping, sorting papers, filing, typing, duplicating, machine calculating,drawing and the editorial preparation of matter for publication, police and fireservice work), handling money (including banking and building society work), andcommunications (including postal, telegraph and radio communications) or radio,television, film, audio or video recording, or performance (not open to the public) andtheir control

Shop and 4 Shops or premises used for a retail trade or business (including the sale to members ofCommercial the public of food or drink for immediate consumption and retail by auction, self-selection

and over-the-counter wholesale trading, the business of lending books or periodicals forgain and the business of a barber or hairdresser) and premises to which the public isinvited to deliver or to collect goods in connection with their hire, repair or other treatment, or (except in the case of repair of motor vehicles) where they themselves maycarry out such repairs or other treatments

Assembly and 5 Place of assembly, entertainment or recreation, including bingo halls, broadcasting,Recreation recording and film studios open to the public, casinos, dance halls, entertainment-,

conference-, exhibition- and leisure- centres, funfairs and amusement arcades,museums and art galleries, non-residential clubs, theatres, cinemas and concert halls,educational establishments, dancing schools, gymnasia, swimming pool buildings, ridingschools, skating rinks, sports pavilions, sports stadia, law courts, churches and otherbuildings for worship, crematoria, libraries open to the public, non-residential daycentres, clinics, health centres and surgeries, passenger stations and termini for air, rail,roa d or sea travel, public toilets, zoos and menageries

Industrial 6 Factories and other premises used for manufacturing, altering, repairing, cleaning,washing, breaking-up, adapting or processing any article, generating power, orslaughtering livestock

Storage and other 7(a) Place for the storage or deposit of goods or materials [other than described under 7(b)]non-residential+ and any building not within any of the Purpose Groups 1 to 6

7(b) Car parks designed to admit and accommodate only cars, motorcycles and passenger orlight goods vehicles weighing no more than 2500 kg gross

* Purpose Group 1 includes –

(a) any surgeries, consulting rooms, offices or similar accommodation not more than 50 m2 in total floor area, formingpart of a dwelling and used by an occupant of the dwelling in a professional or business capacity; and

(b) an attached garage not more than 40 m2 in floor area.

+ A detached garage or open carport not more than 40 m2 in floor area is included in Purpose Group 1(c); as is adetached building which consists of a garage and open carport where neither the garage nor open carport exceeds40m2 in area.

88

Rules for measurement6.3 (a) The area of a roof, rooflight or floorshall be measured as shown in Diagram 6.1.

(b) The cubic capacity of a building, separatedpart or compartment shall be measured (asshown in Diagram 6.2) from –

(i) the upper surface of the lowest floor;

(ii) the under surface of roof or ceilingsurface as appropriate; and

(iii) the inner surfaces of the enclosingwalls or, where there is no enclosing wall,the outermost edge of the floor.

The volume of internal floors, walls andpartitions shall be included for calculationpurposes.

(c) The number of storeys in a building or aseparated part of a building shall be counted asshown in Diagram 6.3, and shall excludebasement storeys.

In a building of Purpose Group 5 a gallery(other than a loading gallery, fly gallery, stagegrid, lighting bridge, or any gallery used forsimilar purposes, or provided for the purposesof maintenance or repair) shall be counted as astorey. In a building of any other purpose groupa gallery shall not be counted as a storey.

(d) The height to a building shall be measuredas shown in Diagram 6.4.

(e) The height to a storey (other than whenmeasuring for firefighting shaft purposes) shallbe measured from the lowest ground leveladjacent to the building to the upper surface ofthe floor in that storey, as shown in Diagram6.5.

(f) The depth of a basement (other than whenmeasuring for firefighting shaft purposes) shallbe measured from the highest ground leveladjacent to the building to the upper surface ofthe floor of the lowest basement storey asshown in Diagram 6.5.

Diagram 6.1 Areas

see para 6.3(a)

B A

(a) Surface area – roofs and rooflights – ineach case measure the visible area

AB

A B

BA

(i) Lean-to roof (ii) Flat or monopitchroof

(iii) Double pitch roof

(iv) Rooflight

door orwindow

measure to the outermost edgeof the floorwhere there isno enclosing wall

(i) Building or room

(ii) Storey, separated part or compartment

(b) Floor area – in each case measure tothe internal surface of enclosing wallsand include internal walls and partitions

89

Diagram 6.3 Number of storeys

see para 6.3(c)

x

basement

whole building threestoreys

2

1

G

x

basement

this separated partthree storeys

2

1

G

this separated parttwo storeys

compartment wall

Note

(1) Count at the position which gives the greatestnumber of storeys.

(2) Where X exceeds 1.2m the building or separatedpart is considered to have two basement storeysand therefore be a two storey building.

Diagram 6.4 Height of a building

see para 6.3(d)

highest point ofroof slope

lowest point ofroof slope

highest level ofground adjacentto outside walls

lowest level ofground adjacentto outside walls

(a) Double pitch roof

mean roof level

mean ground level

height

top level ofupstand

highest point ofroof

highest point ofroof slope

lowest point ofroof slope

highest level ofground adjacentto outside walls

lowest level ofground adjacentto outside walls

mean roof level

mean ground level

height

height Bheight A

mean roof level

mean ground level

use height A or B whichever is greater

(b) Mansard type roof

(c) Flat or monopitch roof

Diagram 6.2 Cubic capacity

see para 6.3(b)

(a) Building

section

(a) Separated part or compartment of a building

section

90

Non-combustible materials

6.4 A non-combustible material is –

(a) a material classified as non-combustiblewhen tested in accordance with BS 476: Part 4:1970 (1984);

(b) a material which when tested inaccordance with BS 476: Part 11: 1982 (1988)does not flame and does not cause a rise intemperature on either the centre (specimen)thermocouple or the furnace thermocouple;

(c) a material which is either totally inorganicor does not contain more than 1% by weight orvolume, of organic material; or

(d) concrete bricks or blocks complying withBS 6073: Part 1: 1981.

Materials of limited combustibility

6.5 A material of limited combustibility is –

(a) a material which can be classified as non-combustible;

(b) a material with a non-combustible core notless than 8 mm thick having combustiblefacings (on one or both sides) not more than0.5 mm thick;

(c) a material of density not less than 300kg/m3 which, when tested in accordance withBS 476: Part 11: 1982 (1988), does not flameor increase the temperature on the furnacethermocouple by more than 20�C; or

(d) in the case of insulation referred to in Table3.3 and paragraph 4.4 - a material of densityless than 300 kg/m3 which, when tested inaccordance with BS 476: Part 11: 1982 (1988)does not flame for more than 10 seconds andthe rise in temperature is not more than 35�Con the centre (specimen) thermocouple and notmore than 25�C on the furnace thermocouple.

Diagram 6.5 Height to a storeyand depth of abasement

see para 6.3(e) and 6.3(f)

height to top storey excludesroof top plant areas

height to astorey

roof

plant

highest level ofground adjacentto outside walls

lowest level ofground adjacentto outside walls

depth of abasement

91

Definitions6.6 In this Technical Booklet the followingdefinitions apply –

Access room – a room that forms the onlyescape route from an inner room.

Accommodation stairway – a stairway,additional to that or those required for escapepurposes, provided for the convenience ofoccupants.

Alternative escape routes – escape routessufficiently separated by either direction andspace, or by fire-resisting construction, toensure that one is still available should theother be affected by fire.

Alternative exit – one of two or more exits,each of which is separate from the other.

Appliance ventilation duct – a duct providedto convey combustion air to a gas appliance.

Atrium – a vertical space within a building,other than a shaft used solely for stairs,escalators, lifts or services, openly connectingthree or more storeys and enclosed at the topby a floor or roof.

Automatic fire detection and alarm system –a system incorporating smoke detectors,sounders, control equipment, protected wiringand a back-up power supply which is capableof automatically detecting smoke andthereupon giving an audible alarm.

Automatic release mechanism – a devicewhich will allow a door held open by it to closeautomatically in the event of each or any one ofthe following –

(a) detection of smoke by automatic apparatussuitable in nature, quality and location;

(b) operation of a hand operated switch fittedin a suitable position;

(c) failure of electricity supply to the device,apparatus or switch; and

(d) operation of the fire alarm system wherefitted.

Automatic self-closing device – does notinclude rising butt hinges unless the door is –

(a) to (or within) a dwelling;

(b) between a dwellinghouse and its garage; or

(c) in a cavity barrier.

Basement storey – a storey with a floor whichat some point is more than 1.2 m below thehighest level of ground adjacent to the outsidewalls.

Cavity barrier – a construction provided toclose a concealed space against penetration ofsmoke or flame, or provided to restrict themovement of smoke or flame within such aspace.

Ceiling – a part of a building which enclosesand is exposed overhead in a room, protectedshaft or circulation space. (The soffit of arooflight, but not the frame is included as partof the ceiling surface. An upstand below arooflight shall be considered as wall.)

Circulation space – a space (including aprotected stairway) mainly used as a means ofaccess between a room and an exit from thebuilding or compartment.

Class O – a product performance classificationfor wall and ceiling linings. The relevant testcriteria are set out in paragraph 2.4.

Compartment – a building or part of a building,comprising one or more rooms, spaces orstoreys, constructed to prevent the spread offire to or from another part of the samebuilding, or an adjoining building. A roof spaceabove the top storey of a compartment isincluded in that compartment.

Compartment floor – a fire-resisting floor usedin the separation of one compartment fromanother.

Compartment wall – a fire-resisting wall usedin the separation of one compartment fromanother.

Concealed space or cavity – a spaceenclosed by elements of a building (including asuspended ceiling) or contained within anelement, but not a room, cupboard, circulationspace, protected shaft or space within a flue,chute, duct, pipe or conduit.

Dead-end – area from which escape ispossible in one direction only.

92

Direct distance – the shortest distance fromany point within the floor area to the neareststorey exit, measured within the externalenclosures of the building, ignoring walls,partitions and fittings, other than the enclosingwalls/partitions to protected stairways.

Element of structure –

(a) a member forming part of the structuralframe of a building or any other beam orcolumn;

(b) a loadbearing wall or loadbearing part of awall;

(c) a floor;

(d) a gallery;

(e) an external wall; and

(f) a compartment wall (including a wallcommon to two or more buildings).

(However, see paragraph 3.6 for exclusionsfrom the provisions for elements of structure.)

Emergency lighting – lighting provided for usewhen the electricity supply to the normallighting fails.

Escape lighting – that part of the emergencylighting which is provided to ensure that theescape route is illuminated at all material times.

Escape route – route forming that part of themeans of escape from any point in a building toa final exit.

Evacuation lift – a lift that may be used for theevacuation of disabled people in the event of afire.

External wall (or side of a building) – includesa part of a roof pitched at an angle of morethan 70� to the horizontal, if that part of the roofadjoins a space within the building to whichpersons have access (but not access only forrepair or maintenance).

Final exit – the termination of an escape routefrom a building giving direct access to a street,passageway, walkway or open space, and sitedto ensure the rapid dispersal of people from thevicinity of a building so that they are no longerin danger from fire or smoke or both.

Fire door – a door or shutter, provided for thepassage of people, air or objects, whichtogether with its frame and furniture as installedin a building, is intended (when closed) to resistthe passage of fire or gaseous products ofcombustion or both, and is capable of meetingspecified performance criteria to those ends. (itmay have one or more leaves, and the termincludes a cover or other form of protection toan opening in a fire-resisting wall or floor, or ina structure surrounding a protected shaft.)

Fire-resisting (fire resistance) – the ability of acomponent or construction of a building tosatisfy for a stated period of time, some or allof the appropriate criteria specified in therelevant Part of BS 476.

Fire stop – a seal provided to close animperfection of fit or design tolerance betweenelements or components, to restrict or preventthe passage of fire and smoke.

Firefighting lift – a lift designed to haveadditional protection, with controls that enable itto be used under the direct control of the FireBrigade when fighting a fire.

Firefighting lobby – a protected lobby forproviding access from a firefighting stairway tothe accommodation area and to any associatedfirefighting lift.

Firefighting shaft – a protected enclosurecontaining a firefighting stairway, firefightinglobbies and, if provided, a firefighting lifttogether with its machinery.

Firefighting stairway – a protected stairwaycommunicating with the accommodation areaonly through a firefighting lobby.

Gallery – a floor, including a raised storagearea, which is less than one-half of the floorarea of the space into which it projects and isopen both above and below to that space.

Inner room – a room from which escape ispossible only by passing through another room(access room).

Materials of limited combustibility –materials which comply with paragraph 6.5.

93

Measurement –

(a) the rules for measuring area, cubiccapacity, number of storeys, height of abuilding and height to a storey are given inparagraph 6.3; and

(b) the methods for measuring occupantcapacity, travel distance, and the width of adoorway, escape route and stairway are givenin Section 1.

Non-combustible material – a material whichcomplies with paragraph 6.4.

Notional boundary – a boundary presumed toexist between buildings on the same site (seeparagraph 4.7).

Open spatial planning – the internalarrangement of a building in which more thanone storey or level is contained in oneundivided volume, e.g. split-level floors. For thepurposes of this Technical Booklet there is adistinction between open spatial planning andan atrium space.

Perimeter (of building) – the maximumaggregate plan perimeter excluding any wallseparating buildings, found by verticalprojection onto a horizontal plane.

Pipe – (for the purposes of Section 3) includespipe fittings and accessories; and excludes aflue pipe and a pipe used for ventilatingpurposes (other than a ventilating pipe for anabove ground drainage system).

Places of special fire risk – oil-filledtransformer and switchgear rooms, boilerrooms, storage space for fuel or other highlyflammable substances and rooms housing afixed internal combustion engine.

Platform floor (access or raised floor) – a floorsupported by a structural floor, but with anintervening concealed space which is intendedto house services.

Pressurization – a method of protectingescape routes against the ingress of smoke bymaintaining the air within them at pressureshigher than those in adjacent parts of thebuilding.

Protected circuit – an electrical circuitprotected against fire.

Protected corridor or lobby – a corridor orlobby which is adequately protected from fire inadjoining accommodation by fire-resistingconstruction.

Protected entrance hall or landing – acirculation area consisting of a hall or spacewithin a dwelling, enclosed with fire-resistingconstruction (other than any part which is anexternal wall or building).

Protected shaft – a shaft which enablespeople, air or objects to pass from onecompartment to another, and which is enclosedwith fire-resisting construction.

Protected stairway – a stairway dischargingthrough a final exit to a place of safety(including any exit passageway between thefoot of the stair and the final exit) that isadequately enclosed with fire-resistingconstruction.

Purpose group – a classification of buildingsor compartments according to the purpose towhich they are intended to be put (seeparagraph 6.2).

Relevant boundary – the boundary which theside of the building faces, (and/or coincideswith) and which is parallel, or at an angle of notmore than 80�, to the side of the building. Anotional boundary can be a relevant boundary.

Rooflight – a domelight, lantern light, skylight,ridge light, glazed barrel vault or other elementintended to admit daylight through a roof.

Room – (for the purposes of Section 2) anenclosed space within a building that is notused solely as a circulation space. (The termincludes not only conventional rooms, but alsocupboards that are not fittings, and largespaces such as warehouses, and auditoria.The term does not include voids such as ducts,ceiling voids and roof spaces.)

Self-contained smoke alarm – an electricalmains powered device (with or without aback-up power source) containing within asingle housing all the components necessaryfor detecting smoke and thereupon giving anaudible alarm.

94

Separated part (of a building) – a form ofcompartmentation in which a part of a buildingis separated from another part of the samebuilding by a compartment wall. The wall runsthe full height of the part, and is in one verticalplane.

Single storey building – a building consistingonly of a ground storey and any basementstoreys. (A separated part which consists of aground storey only, with a roof to which accessis only provided for repair or maintenance, maybe treated as a single storey building.)

Storey exit – a final exit, or a doorway givingdirect access into a protected stairway,firefighting lobby, or external escape route. (Insome circumstances a door in a compartmentwall may be considered as a storey exit, e.g. ina hospital designed for progressive horizontalevacuation.)

Storey – includes –

(a) in a building of Purpose Group 5 – a gallery[other than the exceptions given in paragraph6.3(c)]; and

(b) in a building of any purpose group – a roofwhich is accessible unless it is accessible onlyfor maintenance and repair.

Suspended ceiling (fire-protecting) – a ceilingsuspended below a floor, which contributes tothe fire resistance of the floor.

Thermoplastic material – a syntheticpolymeric material which can be classified inaccordance with paragraph 2.4 or 2.5.

Travel distance – the actual distance to betravelled by a person from any point within thefloor area to the nearest storey exit, havingregard to the layout of walls, partitions andfittings.

Unprotected area – in relation to a side orexternal wall of a building means –

(a) a window, door or other opening;

(b) any part of the external wall which has lessthan the relevant fire resistance set out in Table3.1; and

(c) any part of the external wall which hascombustible material more than 1 mm thickattached or applied to its external face, whetherfor cladding or any other purpose.

Wall – (for the purposes of Section 2)includes –

(a) the surface of glazing (except glazing indoors); and

(b) any part of a ceiling which slopes at anangle of more than 70� to the horizontal, andexcludes –

(i) doors and door frames;

(ii) window frames and frames in whichglazing is fitted;

(iii) architraves, cover moulds, picturerails, skirtings and similar narrowmembers; and

(iv) fireplace surrounds, mantleshelvesand fitted furniture.

95

BS 476: Fire tests on building materials andstructures

Part 3: 1958 External fire exposure rooftest

Part 4: 1970 (1984) Non-combustibility testfor materialsAMD 2483 March 1978AMD 4390 September 1983

Part 6: 1981 Method of test for firepropagation for productsAMD 4329

Part 6: 1989 Method of test for firepropagation for products

Part 7: 1971 Surface spread of flame testsfor materials

Part 7: 1987 (1993) Method forclassification of the surface spread offlame of productsAMD 6249 January 1990AMD 7030 January 1992AMD 7612 April 1993

Part 8: 1972 Test methods and criteria forthe fire resistance of elements of buildingconstructionAMD 1873 January 1976AMD 3816 November 1981AMD 4822 May 1985

Part 11: 1982 (1988) Method for assessingthe heat emission from building materials

Part 20: 1987 Method for determination ofthe fire resistance of elements ofconstruction (general principles)AMD 6487 April 1990

Part 21: 1987 Methods for determinationof the fire resistance of loadbearingelements of construction

Part 22: 1987 Methods for determinationof the fire resistance of non-loadbearingelements of construction

Part 23: 1987 Methods for determinationof the contribution of components to thefire resistance of a structure

Part 24: 1987 Method for determination ofthe fire resistance of ventilation ducts

Section 31.1: 1983 Method ofmeasurement under ambient temperatureconditions

BS 747: 1977 (1986) Specification for roofingfelts

AMD 3775 November 1981AMD 4609 February 1985AMD 5101 February 1986

BS 2782: Method of testing plastics

Part 1: 1976 Method 120A

Part 5: 1970 Miscellaneous methodsAMD 1524 July 1974

BS 4514: 1983 Specification for unplasticizedPVC soil and ventilating pipes, fittings andaccessories

AMD 4517 June 1984AMD 5584 November 1987

BS 5255: 1989 Specification for thermoplasticswaste pipe and fittings

BS 5266: Emergency lighting

Part 1: 1988 Code of practice for theemergency lighting of premises other thancinemas and certain other specifiedpremises used for entertainment

BS 5306: Fire extinguishing installations andequipment on premises

Part 1: 1976 (1988) Hydrant systems,hose reels and foam inletsAMD 4649 August 1984AMD 5756 February 1988

Part 2: 1990 Specification for sprinklersystems

BS 5395: Stairs, ladders and walkways

Part 2: 1984 Code of practice for thedesign of helical and spiral stairsAMD 6076 July 1989

BS 5438: 1989 Methods of test for flammabilityof textile fabrics when subjected to a smalligniting flame applied to the face or bottomedge of vertically oriented specimens

AMD 6509 June 1990

Appendix – Publications referred to

96

BS 5446: Components of automatic fire alarmsystems for residential premises

Part 1: 1990 Specification for self-contained smoke alarms and point-typesmoke detectorsAMD 6863 September 1991AMD 7648 May 1993

BS 5499: Fire safety signs, notices and graphicsymbols

Part 1: 1990 Specification for fire safetysignsAMD 7444 January 1993

BS 5588: Fire precautions in the design,construction and use of buildings

Part 4: 1978 Code of practice for smokecontrol in protected escape routes usingpressurizationAMD 5377 September 1986

Part 5: 1991 Code of practice forfirefighting stairs and liftsAMD 7196 June 1992

Part 6: 1991 Code of practice for places ofassembly

Part 8: 1988 Code of practice for means ofescape for disabled people

Part 9: 1989 Code of practice forventilation and air conditioning ductwork

Part 10: 1991 Code of practice forshopping complexes

BS 5839: Fire detection and alarm systems forbuildings

Part 1: 1988 Code of practice for systemdesign, installation and servicingAMD 6317 January 1991AMD 6874 May 1992

BS 5867: Specification for fabrics for curtainsand drapes

Part 2: 1980 (1993) FlammabilityrequirementsAMD 4319 July 1983

BS 6073: Precast concrete masonry units

Part 1: 1981 Specification for precastconcrete masonry unitsAMD 3944 March 1982AMD 4462 February 1984

BS 6387: 1994 Specification for performancerequirements for cables required to maintaincircuit integrity under fire conditions

CP 144: Roof coverings

Part 3: 1970 Built-up bitumen felt. MetricunitsAMD 2527 April 1978AMD 5229 June 1986

CP 1007: 1955 Maintained lighting for cinemas

BR 128: 1988 Guidelines for the construction offire-resisting structural elements

BR 135: 1988 FIre performance of externalthermal insulation for walls of multi-storeybuildings

BR 187: 1991 External fire spread: buildingseparation and boundary distances

Fire Services (Northern Ireland) Order 1984 asamended 1993

The Steel Construction Institute 1990: Fire andsteel construction: The Behaviour of SteelPortal Frames in Boundary Conditions (2ndEdition)