B5 Access and facilities for the fire service

A building shall be so designed and constructed that there is adequate provision for access for fire appliances and for such other facilities as may be reasonably required to assist the fire service in the protection of life and property.

Performance

The requirement of B5 may be met:

a. if there is sufficient means of external access to enable fire appliances to be brought near to the building for effective use;

b. if there is sufficient means of access into, and within, the building for fire-fighting personnel to effect rescue and fight fire; and

c. if the building is provided with sufficient firemains and other facilities to assist firefighters in their tasks;

all to an extent dependent on the use and size of the building.

5.0 Introduction to Provisions

Scope

5.0.1 While the fire safety objectives of Part B relate principally to the protection of life from fire (see 0.3.8), Section B5 relates to measures intended to assist the fire services in the protection of life and property from fire.

Fire authorities have functions under the Fire Services Act, 1981 to provide fire brigades for the extinguishment of fires and for the protection and rescue of persons and property from injury by fire. Regulation B5 provides for the provision of access and other facilities to assist the fire service in the protection of life and property from fire.

The guidance in this Section relates to the provision of facilities for the fire service within and around buildings for the purpose of protecting life and mitigating property damage due to fire.

To assist the fire service some or all of the following facilities may be necessary, depending mainly on the size of the building:

vehicle access to the building for fire appliances;
access to and within the building for fire fighting personnel;
fire mains around and within buildings, including the provision of hydrants;
provisions for venting of heat and smoke from basement areas and other spaces;
other facilities such as foam inlets to basement boiler-houses and fuel storage and electrical isolation switches.

Factors Determining Facilities Appropriate to a Specific Building

5.0.2 The main factor determining the facilities needed to assist the fire service is the size of the building.

The facilities provided also depend on the expected method of fire fighting; whether this will be from outside or inside the building. T
he following considerations will determine the extent of the facilities required for any particular situation:

a. In many instances fire fighting is carried out within the building. In deep basements and tall buildings fire fighters will invariably work inside. T hey need special access facilities (see sub-section 5.3), equipped with fire mains, as described in sub-section 5.1. Fire appliances need access to entry points near the fire mains, as described in sub-section 5.2.

b. In other buildings the combination of personnel access facilities offered by the normal means of escape, and the ability to work from ladders and appliances on the perimeter is sufficient without special internal arrangements. Depending on the size of the building, vehicle access may be needed to some or all of the perimeter, as explained in sub-section 5.2.

c. Access for personnel to basement areas may in particular present difficulties, as the products of combustion from a fire tend to escape by way of the stairways. This problem can be reduced by the provision of ventilation. Ventilation may also be appropriate in other situations, particularly from large spaces within buildings. Venting can improve visibility and reduce temperatures, thus assisting search, rescue and fire fighting. Guidance on ventilation for fire fighting is indicated in 5.4.3.

d. Water is the normal extinguishing medium for fire within buildings. Water is obtained in the first instance from the supplies carried on the first responding fire appliances. T his is supplemented with water from public mains or fire mains on the site, where available, or pumped from other adjacent sources such as rivers, canals, ponds or static storage tanks, where provided. Water may also be ferried by water-carrying tankers or relayed by pumping from remote sources. Guidance on the provision of fire mains is given in sub-section 5.1.

e. Certain areas, such as boiler rooms and fuel storage areas within buildings require special provisions, such as facilities for pumping foam extinguishing medium from outside. Other facilities may be required to isolate electrical supplies, particularly in the case of high voltage installations. G idance on these special provisions is contained in sub-section 5.4.

Existing Buildings

5.0.3 In the case of a material alteration of an existing building, the requirements of B5 of the Second Schedule to the Building Regulations may be met:

if the access and facilities for the fire service are not altered in such a way as to reduce the extent or performance of those that existed before the material alteration; and
if the building is not extended or altered by the addition of floor area at any level or the subject of a material change of use.

In the case of a material change of use of a building, it will be necessary to assess the access and facilities for the fire services in accordance with the guidance of the relevant sub-section to this Section. However, in relation to vehicle access, special provisions are made for existing buildings (see 5.2.3). It may also be prudent to seek advice from the relevant fire authority in relation to such matters.

Definitions

5.0.4 The following definitions apply specifically to B5. Other terms applicable more widely throughout this Document are given in Appendix D.

Firefighting lift: a lift designed to have additional protection, with controls that enable it to be used under the direct control of the fire brigade in fighting a fire.

Firefighting lobby: a protected lobby for providing access from a firefighting stairway to the accommodation area and to any associated firefighting lift.

Firefighting shaft: a protected shaft containing a firefighting stairway, firefighting lobbies and, if provided, a firefighting lift.

Firefighting stairway: a protected stairway communicating with the accommodation area only through a firefighting lobby.

Fire mains: pipes installed in and around buildings and equipped so that the fire service may connect hoses to receive a supply of water for fire fighting.

Hydrant: an assembly comprising a valve and outlet connection from an external fire mains, provided to deliver a supply of water for fire-fighting.

Perimeter (of buildings): The maximum aggregate plan perimeter, formed by vertical projection onto a horizontal plane but excluding any parts which are connected to adjoining buildings (see Diagram 31).

5.1. Fire Mains

Introduction

5.1.1 Fire mains are pipes installed in and around a building and equipped so that the fire service may connect hoses to receive a supply of water to fight fires. Fire mains are divided into two types as follows:

internal fire mains (see 5.1.2); and
external fire mains and hydrants (see 5.1.7, 5.1.8).

Provision of Internal Fire Mains

5.1.2 Internal fire mains may be of two types:

rising mains, serving floors above ground or access level; or
falling mains serving levels below ground or access level.

Internal fire mains may also be of the "dry" type which are normally empty and are supplied through hose from a fire service pumping appliance, or they may be of the "wet" type kept full of water and supplied from tanks and pumps in the building.

Internal fire mains should be provided in all buildings where a firefighting shaft is also required (see 5.3). T he following provisions are required for the situations as described:

a. in buildings with a floor at more than 20m above ground level, storeys above ground level should be equipped with wet or dry rising fire mains;

b. in buildings with a basement at more than 10m below ground level, basement storeys should be equipped with wet or dry fire mains;

c. in buildings with any floor at more than 60m above ground level, storeys above ground level should be equipped with wet rising fire mains.

Number and Location of Internal Fire Mains

5.1.3 Where internal fire mains are installed, they should be positioned so that at each level other than ground level there is one main for every firefighting shaft provided to meet the provisions in paragraph 5.3.3.

If there are no firefighting shafts but internal fire mains are to be installed, the criteria in par. 5.3.3 for the number and location of firefighting shafts may be used to determine the provision of internal fire mains, even though the building may not have a storey at more than 20 m above ground level.

5.1.4 The outlets from internal fire mains should be sited in:

a. a firefighting shaft (see sub-section 5.3), or

b. a protected stairway, or

c. a balcony or walkway in the open air.

Design and Construction of Internal Fire Mains

5.1.5 The design and construction of internal fire mains should be in accordance with the relevant sections of BS 5306: Part 1: 1988 (excluding clause 6).

Sources of Water for Firefighting

5.1.6 Water for firefighting is available by way of a number of possible sources as follows:

a. Water carried on fire appliances (water tenders, water tankers, etc.);

b. Hydrants on external fire mains;

c. Static storage tanks or reservoirs where provided;

d. Other sources such as rivers, canals, ponds, etc.,where adequate access for pumping is available.

Provision of Hydrants

5.1.7 The following buildings should be provided with one or more external fire hydrants, complying with the requirements of BS 750: 1984 Specification for underground fire hydrants and surface box frames and covers, and with any specific requirements of the relevant fire authority:

every building provided with an internal fire main, wet or dry;
every building having a floor area on any storey of more than 1000 m2;

For buildings, or groups of buildings, exceeding 1000 m2 in ground floor area, at least one hydrant should be provided for every 1000 m2 of the area covered at ground level.

Fire hydrants should be located as shown in Diagram 30 and such that:

the distance from the building is not less than 6 m or more than 46 m;
the distance from a hydrant to a vehicle access roadway or hard-standing area for fire appliances (see 5.2) is not more than 30 m;
they are distributed around the perimeter of the building, having regard to the provision of access for fire appliances (see 5.2): and
the hydrants are located on the same site as the building or are provided by a sanitary authority on a public roadway adjacent to the site.

Diagram 30 External fire mains and hydrants Par. 5.1.7

A hydrant situated inside a building may also be acceptable where it is:

in a separate fire compartment i.e. separated from the rest of the building by compartment walls;
not more than 4.5 m and visible from an entrance to the building; and
indicated by a suitable notice at the entrance.

All hydrants should be conspicuously marked in accordance with BS 3251: 1976 Specification of indicator plates for fire hydrants and emergency water supplies.

External Fire Mains

5.1.8 Most urban areas are supplied with water through public water mains. Where such mains are provided it is normal to have hydrants provided for the fire brigade to obtain a ready supply of water for firefighting. The siting of these hydrants is important both from the point of view of accessibility for fire brigade use and proximity to buildings for quick and effective firefighting (see 5.1.7).

The provision of water mains, and suitably located hydrants outside of the site of a building does not come within the scope of the Building Regulations.

In many cases, especially for smaller developments in urban areas, hydrants on public water mains will be adequate. However, for larger buildings, the hydrants available from the public mains outside of the site may not be sufficient for firefighting. In these situations, hydrants on external fire mains within the site of the building will provide the most convenient source of water. This source may be supplemented by hydrants on public mains or other sources indicated at 5.1.6.

Where required to provide hydrants in accordance with 5.1.7, fire mains should be designed to be capable of providing satisfactory flows and pressures. Guidance for the design of hydrant systems is contained in BS 5306: Part 1: 1976. For improved and more reliable supplies, external fire mains on a site should preferably be installed as part of a ring main system.

5.2. Vehicle Access

Introduction

5.2.1 Fire brigade vehicle access to the exterior of a building is required to enable high reach appliances, such as turntable ladders and hydraulic platforms, to be deployed, and to enable pumping appliances to supply water and equipment for firefighting.

Access requirements increase with building size and height and also depend on whether the building is fitted with internal fire mains (see 5.1).

Access for fire appliances should be provided in accordance with the provisions outlined in 5.2.2 below.

Vehicle access routes and hard-standings should meet the criteria described in 5.2.4 if they are to be used by fire service vehicles.

Provision of Vehicle Access

5.2.2 For effective firefighting operations, fire brigade appliances should be able to get within easy reach of a building. For small buildings it is generally only necessary to have access to one external elevation, but larger buildings will require access to all or a number of elevations.

Vehicle access should be provided in accordance with the criteria indicated in Table 5.1. Any elevation to which vehicle access is provided in accordance with Table 5.1 should contain a door giving access to the interior of the building.

In the case of a building fitted with a dry internal fire main, access for a pump appliance should be provided to within 18 m and within sight of the inlet connection point.

In the case of a building fitted with a wet internal fire main, access for a pump appliance should be provided to within 18 m and within sight of an entrance giving access to the main and within sight of the inlet connection to the suction tank for the main.

In the case of a building which has adjoining buildings on one or more sides, the perimeter (see 5.0.4 and Diagram 31 for the definition of ‘perimeter’) which is available to provide access is less than for a freestanding building. Where there are adjoining buildings on more than two sides, the access requirement derived from T able 5.1 may not therefore be adequate. In these situations it may be appropriate to consult with the relevant fire authority in relation to access and other facilities or compensating features as are considered necessary.

In the provision of access for fire appliances, consideration should also
be given to the position of any hydrants required by reason of the criteria outlined in 5.1.

Existing Buildings

5.2.3 In the case of existing buildings, where access for fire appliances is not in accordance with the provisions outlined at 5.2.2, it is appropriate to consider a range of compensating measures, depending on the circumstances of each particular case. Such measures could include additional personnel access (see 5.3) to the building for firefighting, additional internal fire mains (see 5.1) and other facilities to assist firefighting.

In the case of an existing small building, with a total floor area of up to 1000 m2 where the height of the top storey is under 10 m, access for fire service pump appliances should generally be provided to within 45 m of the principal entrance to the building.

In large or complex buildings it will be necessary to provide access to within a reasonable distance of a number of points on the exterior and to within a reasonable distance of other entry points to the building. In these cases it may be appropriate to consult with the relevant fire authority in this regard.

Table 5.1 Vehicle access to buildings

Table 5.2 Vehicle access route specifications

Design of Access Routes and Hardstandings

5.2.4 A vehicle access route may be a public or private road, or other route, which, including any manhole or other covers, meets the standards in Table 5.2, Diagram 32 and the following paragraphs.

Access routes to buildings with any storey at more than 10 m above ground level should meet the standards for high reach appliances. For lower buildings the access should be to the standards for pumping appliances.

Where access is provided to an elevation in accordance with Table 5.2, overhead obstructions such as overhead cables that would interfere with the setting of ladders etc., should be avoided in the area shown on Diagram 32.

Where access roadways are provided within the site of a building, turning facilities for appliances, in accordance with the requirements of T able 5.2 should be provided in any dead-end access route that is more than 20 m long.

Table 5.2 Vehicle access route specifications

Diagram 31 Building perimeter

Diagram 32 Fire appliance (high reach) access to buildings

5.3. Personnel Access to Buildings for Firefighting

Introduction

5.3.1 In low rise buildings without deep basements fire service personnel access requirements may be met by a combination of the normal means of escape, and the measures for vehicle access in sub-section 5.2, which facilitate ladder access to upper storeys. In other buildings the problems of reaching the fire, and working inside near the fire, merit the provision of additional facilities to avoid delay and to provide a sufficiently secure operating base to allow effective action to be taken.

These additional facilities include firefighting lifts, firefighting stairways and firefighting lobbies, which are combined in a protected shaft known as the firefighting shaft (Diagram 33).

Provisions for protected shafts in general are given in Section B3.

Diagram 33

Provision of Firefighting Shafts

5.3.2 Buildings with a floor at more than 20 m above ground level or with a basement at more than 10 m below ground level, should be provided with firefighting shafts containing firefighting lifts.

Every firefighting stairway and firefighting lift should be approached through a firefighting lobby (see Diagram 33).

In a building containing flats (Purpose Group 1(c)) (see 1.1.2), a firefighting lobby should be provided.

There should not be direct access to a flat or ancillary accommodation from a firefighting lobby. The firefighting lobby facilitates ongoing evacuation of occupants, and concurrent firefighting operations.

A firefighting stairway should serve every storey of the building.

A firefighting lift should serve every storey above ground, including the ground floor, in a building with any floor 20 m or more above ground. However a firefighting lift need not serve a storey in a building used as flats (purpose group 1(c)) on which there is no entrance to a dwelling. A firefighting lift should also serve every storey below ground, and the ground floor, in a building with a basement at more than 10 m below ground.

Number and Location of Firefighting Shafts

5.3.3 The number of firefighting shafts should:

a. (if the building is fitted throughout with an automatic sprinkler system meeting the relevant recommendations of BS 5306: Part 2) comply with Table 5.3; or

b. (if the building is not fitted with sprinklers) be such that there is at least one for every 900 m2 (or part thereof) of floor area of the largest floor that is more than 20 m above ground level.

The location of firefighting shafts should be such that every part of every storey, other than fire service access level, is no more than 60 m from the entrance to a firefighting lobby, measured on a route suitable for laying hose. If the internal layout is unknown at the design stage, then every part of every such storey should be no more than 40 m in a direct line from the entrance to a firefighting lobby.

Table 5.3 Minimum number of firefighting shafts in buildings fitted with sprinklers

Firefighting shaft walls should be of robust construction so that their fire resistance is unlikely to be impaired by mechanical damage.

Design and Construction of Firefighting Shafts

5.3.4 All firefighting shafts should be equipped with internal fire mains having outlet connections and valves in every firefighting lobby except at access level.
Firefighting shafts should be designed and installed in accordance with the recommendations of BS 5588: Part 5: 2004 Code of practice for fire-fighting stairs and lifts in respect of the following:

planning within the firefighting shaft
fire mains and landing valves
smoke control
fire resistance
fire doors
glazed areas

-firefighting lift installation

electrical supply
fire brigade communications system

Firefighting shaft walls should be of robust construction so that their fire resistance is unlikely to be impaired by mechanical damage.

5.4 Areas Requiring Special Consideration

There are a number of situations which pose particular difficulties and where additional facilities should be provided to assist the fire brigades.

Boiler Rooms and Fuel Stores

5.4.1 In buildings where the heating installation is oil-fuelled, and in particular where the oil storage tanks and oil burning equipment are situated below ground level, a fire involving the fuel and equipment can be tackled by the fire brigade using foam, introduced into the heating or storage chamber through foam inlets.

Every room which contains oil burning equipment or has storage tanks of greater capacity and situated as in Table 5.4 should be provided with a foam inlet for use by the fire brigade.

The inlet should be sited on an external wall not more than 900 mm above ground level and at least 3 m horizontally from any opening to the protected room to ensure that the fire brigade personnel are able to use the inlet without hindrance from heat and smoke which may emerge from the opening.

The pipe from its inlet coupling should have an internal diameter of 80 mm (nominal), be without acute bends and not exceed 10 m in length to the point of discharge of the foam. Inlets should be fitted with a 63.5 mm instantaneous coupling complying with BS 336: 1989.

The discharge of foam should be so arranged to impinge on a wall approximately 900 mm above the floor level of the room or 150 mm above the catch pit level, whichever is the higher.

High Voltage Discharge Lighting

5.4.2 Where high voltage discharge lighting is used inside or outside buildings, fire brigade personnel could be in considerable danger during fire fighting operations. It is therefore necessary to provide a switch, readily accessible to fire fighters, which will enable them to turn off and isolate this high voltage lighting before commencing fire fighting.

5.4.2.1 Provision of switches One or more switches should be provided to enable the fire brigade personnel to switch off the discharge lighting in the event of a fire. Such switches are needed where exterior discharge lighting (e.g. advertising signs) and/or interior discharge lighting systems are provided. The switches should be readily accessible and conspicuously marked to enable fire fighters to switch them off without delay.

A firefighting emergency switch should be provided for:

exterior discharge lighting installations operating at a voltage exceeding low voltage; and
interior discharge lighting installations operating unattended at a voltage exceeding low voltage.

Table 5.4 Provision of foam inlets

For the purposes of these provisions an installation in a closed market or in an arcade is considered to be an exterior installation.

5.4.2.2 Requirements for switches Every firefighting emergency switch provided should comply with all the relevant requirements of the following items (i) to (iv).

a. For exterior installations, the switch should be outside the building and adjacent to the discharge lamp(s), or, alternatively, a notice indicating the position of the switch shall be placed adjacent to the discharge lamp(s) and a nameplate should be fixed near the switch so as to render it clearly distinguishable.

b. For interior installations, the switch should be in the main entrance to the building or in another position to be agreed with the local fire authority.

c. The switch should be placed in a conspicuous position, reasonably accessible to fire fighters and, except where otherwise agreed with the local fire authority, at not less than 2.75 m from the ground.

d. Where more than one switch is installed on anyone building, each switch should be clearly marked to indicate the installation or part of the installation which it controls, and the local fire authority should be notified accordingly.

Note: Wherever practicable, all exterior installations on any one building should be controlled by a single fireman's switch. Similarly, all internal installations in any one building should be controlled by a single fire fighter's switch independent of the switch for any external installation.

For the purpose of the above provisions, low voltage is defined as not exceeding 1000 V a.c, or 1500 V d.c. between conductors, or 600 V a.c. or 900 V d.c. between any conductor and earth.

Ventilation of Heat and Smoke

5.4.3 Ventilation of heat and smoke plays an important role in fire-fighting operations. How this can be achieved, if and when required, is generally a matter for the fire brigade. However, certain design features will assist in this regard. Fire-fighting in basement areas can present difficulties with access for personnel and in these situations ventilation which is independent of any stairways will be of assistance.

Provisions for ventilation in car parks are included in 3.5.2. These provision principally relate to the fire resistance requirements for the elements of structure, but will also assist fire-fighting.

5.4.3.1 Basements Smoke ventilation from basements generally take the form of outlets vents connected directly to the open air. Such ventilation should be provided from every basement storey except in the following:

a. a basement in a dwelling house (Purpose Group1(a) and 1(b));

b. a basement having an area less than 200 m2 and a floor which is not more than 3 m below the adjacent ground level.

Smoke vents should be sited at high level and should be distributed around the building perimeter to maximise the effectiveness of cross-ventilation. The clear cross-sectional area of all smoke vents, allowing for frames and louvres, should not be less than 2.5% of the basement storey served. Where a basement is compartmented, each compartment should be ventilated separately. Generally, smoke vents from basements should be permanently open and unobstructed, but where they are readily accessible from the outside, consideration can be given to suitably indicated removable covers. Smoke vents should not be positioned where they would prevent the use of the means of escape from the building.

As an alternative to outlet vents as described above, a system of mechanical extraction may be provided, where the basement is also protected by an appropriate sprinkler system complying with BS 5306: Part 2: 1990. The ventilation system should meet the criteria set out in 3.5.2.5 and should operate automatically on activation of the sprinkler system.

Basement car parks are not normally expected to be fitted with sprinklers.

5.4.3.2 Escape stairways Smoke control in escape stairways is of assistance at the later stages in the development of a fire and will assist fire brigade operations. Smoke control is usually provided by openable windows or openable vents at the top of the enclosure. Every protected stairway enclosure should be provided with:

openable windows at each upper storey or landing; or
an openable vent having clear openable area of not less than 1 m2 situated at the top of the enclosure. This vent should be automatically opened by activation of smoke detectors in the stairway enclosure and should also be manually openable for fire brigade use.

5.4.3.3 Large undivided and windowless spaces Large undivided floor areas can present difficult firefighting problems. The accumulation of heat and smoke in a fire may prevent access to these areas and limit the potential for rescue and effective firefighting from within the building. The provision of smoke and heat venting can greatly improve the effectiveness of such operations.

Fire extinguishment is normally accomplished by absorption of heat by water from hose streams or sprinklers. The reduction of heat build-up within the building by adequate venting facilities can reduce the amount of water required for cooling and extinguishment. However, ventilation is not a substitute for sprinklers or other extinguishing facilities. Its purpose is to release smoke and heat from the building and to improve accessibility for the fire services.

The principles described above are equally applicable to large windowless accommodation, where a fire has very limited ability to vent to the outside, and thereby giving rise to difficulties with firefighting operations.

Facilities for ventilation of smoke and heat for the purpose of assisting the fire service in the protection of life and property should be provided in single storey buildings or compartments exceeding 4,000 m2 in area or 20,000 m3 in cubic capacity (see Appendix C , Diagram 35) having the following uses:

Shop (Purpose Group 4),
Industrial (Purpose Group 6), or
Storage (Purpose Group 7).

Ventilation facilities include roof mounted exhaust ventilators of suitable size and distribution and adequate inlet air provisions. The space below the roof generally requires division into smoke reservoirs of appropriate dimensions. Ventilation may also be provided or supplemented by the nature of the roof/building fabric, such as by the use of rooflights. It may also be possible to provide inlet air from adjacent smoke reservoirs or by means of external windows or doors. Facilities for the ventilation of heat and smoke for firefighting purposes are not generally required to operate automatically.

Guidance on the design of ventilation systems appropriate for these purposes are contained in Section 3, Chapter 9 of the Society of Fire Protection Engineers "Handbook of Fire Protection Engineering" (2nd Edition). Guidance is also contained in the National Fire Protection Association Fire C ode 204M "Guide for Smoke and Heat Venting".

Note: Ventilation of heat and smoke may also be required for the purpose of protecting the means of escape (see Section B1) in large and complex buildings such as shopping centres (see also 3.5.3), large assembly and recreation buildings and buildings with an atrium (see 3.5.5).