United Kingdom

England and Wales adopted one of the earliest performance-based building codes for fire in 1985 (35). Similar to New Zealand, the UK Building Act 1984 is the primary legislation under which the Building Regulations are enforced. This is applicable to England and Wales but not to Scotland or Ireland. For building work, the UK Building Regulations specify technical requirements which are required to be met. Guidance on meeting these technical

requirements is provided in the form of 'approved documents'. Approved Document B (36) is one of 14 such documents and is specific to fire safety.

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In 2006 The Regulatory Reform (Fire Safety) Order 2005 came into effect and replaced over 70 pieces of fire safety law (37) throughout the UK. The 2005 order applies to all non- domestic premises in England and Wales and had a significant effect on how fire safety is managed in the UK, with a strong influence on fire safety risk assessment. From a design perspective, a comprehensive range of guidance documents and standards are available dependent on the nature of the building being designed, the method of design and the complexity of the project. BS 9999 (25) provides a three-tiered hierarchy to define the approaches and methods that should be used for fire engineering in the UK:

a) General approach. This level is applicable to a majority of building work

undertaken within the UK. In this case the fire precautions designed into the building usually follow the guidance contained in the documents published by the relevant government departments to support legislative requirements.

b) Advanced approach. This is the level for which BS 9999 is provided. Guidance provided in this document gives a more transparent and flexible approach to fire safety design through use of a structured approach to risk-based design where designers can take account of varying physical and human factors. Much of the guidance in BS 9999 is based on fire safety engineering principles, although it is not intended as a guide to fire safety engineering.

c) Fire safety engineering. This is the level for which BS 7974 is provided. This level provides an alternative approach to fire safety and can be the only practical way to achieve a satisfactory standard of fire safety in some large and complex buildings, and in buildings containing different uses.

Documentation supporting all three approaches contains specific advice and details of how to satisfy the performance requirements for fire-fighting needs of the Building Code. The following sections provide relevant observations from each of the three documents supporting these different approaches.

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5.4.1. General Approach – Approved Document B

Section B5 of Approved Document B (36) provides the requirements for access and facilities for the fire and rescue services. Of specific note is that the document acknowledges the impact of fire-fighting intervention on means of escape strategies from some large buildings. Section 4.27 recognises that fire fighters entering stairs may impede evacuating occupants and recommends that for buildings in excess of 30 m in height special management

procedures be put into place in consultation with the relevant fire and rescue service. However, for buildings in excess of 45 m physical measures may be required, and

discounting a stair is suggested. The recommendation for an additional stair should also be recognised to be in addition to other dedicated measures such as vertical shafts or fire- fighting shafts specifically designed for fire-fighters‘ use.

5.4.2. Advanced Approach – BS 9999

Section 6 of BS 9999 (25) is dedicated to the requirements surrounding access and facilities for fire fighting. Both Approved Document B and BS 9999 require far more comprehensive fire-fighting facilities than New Zealand's equivalent, C/AS1. Of interest in section 20 of BS 9999 is that the introduction recognises that facilities should be provided to assist fire fighters in undertaking more than just rescue operations. Also, the need to ensure that fire fighters are provided with places of relative safety within buildings is relevant to

understanding the needs of fire fighters while operating within buildings. Text from section 20 of BS 9999 is provided below with emphasis added to these points:

Fire-fighting facilities should be selected and designed to assist the fire and rescue service in protecting life, protecting fire-fighters, reducing building losses,

salvaging property and goods and minimizing environmental damage. Early consultation with appropriate approving authorities (including the fire and rescue service and building control bodies) is recommended when deciding which facilities should be provided. Fire-fighting facilities should include, where appropriate:

a) the provision of vehicular access for fire appliances to the perimeter of the building or site;

b) provision of easy and speedy entry to the site and/or the interior of the building for fire-fighters and their equipment;

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c) provision of and access to sufficient supplies of a fire-fighting medium;

d) means of enabling fire-fighters, once they have entered a building, to reach any point within that building in the shortest possible time, including the provision of fire- fighting lifts if appropriate;

e) means of ensuring that once fire-fighters have arrived at a location within a

building, they can remain there in relative safety whilst they carry out their fire-fighting operations;

f) provision for fire and rescue service communications;

g) provision of facilities to release, or extract, smoke and heat from the building or site;

h) provision for removing spent fire-fighting extinguishing medium.

5.4.3. BS 7974 – Fire Safety Engineering

The published document PD 7974 Part 5 (4) is specific to 'fire service intervention' and is provided to support the code of practice, BS 7974:2001, Application of fire safety

engineering principles to the design of buildings(38). This is a directly relevant document to the consideration of fire brigade intervention and the FBIM. Section 4 provides the general guidance for any analysis and specifically notes that:

Consideration needs to be given regarding physiology data of fire-fighters, heat stress, training, fire-fighting techniques, breathing apparatus constraints etc.

Of particular relevance is that the document provides no accepted engineering method to establish intervention times, as it states that this is difficult to quantify and provides only qualitative times based on judgement;

fire service activities are not easy to quantify. Many aspects of this Published Document have to be based on qualitative judgement rather than on numerical calculations.

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Section 5 provides the inputs required for the analysis which include:

Building characteristics

o Building layout and geometry

o Building location

o Access to the building

o fire service facilities Physiology of fire-fighters Design fire

Time of fire service notification Evacuation time

Environmental influences on smoke control Vehicle access

Water supplies

Single-storey and multi-storey complexes Fire-fighting shafts

Fire-fighting stairs, lobbies and lifts

The outputs for the analysis required are given as:

Time of fire service intervention Fire service extinguishing capability

The similarities between PD7974 and that of the FBIM can be seen diagrammatically in Figure 15, which shows the results of a PD7974 analysis of fire service intervention.

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Figure 15 The defined stages of 'Fire service intervention' taken from PD7974-5

The similarities between PD7974 and the FBIM as a way of quantifying fire-fighting needs on a performance basis could be considered to provide a level of validity to FBIM and the respective methodologies and also suggests that they are sound and transferable between countries and across codes. However, the weakness with PD7974 is that it lacks credibility from an engineering sense as the values or data required for any analysis are too generic and not building-specific and are largely qualitative in nature. This is problematic from a true performance perspective as generic qualitative data will ultimately produce a generic

prescriptive result. The obvious example of this is that the arrival time of the fire service is predicated on government recommended national standards of fire cover rather than actual resourcing and response times associated with buildings in specific areas and serviced by a local fire service with specific characteristics. This is further discussed below in section 7.5.2 Historical Background to Fire Service Response Times.

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