Performance Based Design, Expertise Asymmetry, and Professionalism: Fire Safety Regulation in the Neoliberal Era

AbstractFire safety has traditionally been regulated by prescriptive rules that stipulate requirements according to the type and size of building, with the regulator’s job being to check that these rules have been followed. However, many jurisdictions now allow Performance-Based Design regulation in which approval depends on the regulator assessing the prospective performance of a bespoke fire safety design for a particular project. Regulators thus need to be able to adjudicate on the knowledge claims put forward by fire safety engineers, but most regulators lack the knowledge to interrogate claims that are often the product of complex mathematical modelling across a range of disciplines. This expertise asymmetry poses a challenge for effective regulation of fire safety designs, and the relative immaturity of fire safety engineering as a profession needs to be addressed before it would be wise to rely on professional competence and ethics alone to ensure safety.

Keywords

Fire safety, Deregulation, Performance-Based Design, Professionalism, Regulation

IntroductionBuildings are one of the oldest and most ubiquitous of technologies, and like all technologies, they have both benefits and risks. The biggest risk associated with most buildings continues to be fire, as it has been in most locations and historical periods (Bankoff et al 2012). Societal actions to reduce fire risks can claim to be one of the earliest forms of regulation of technology, with examples cited from Roman times (e.g. Dando-Collins 2010). Fire safety regulations have evolved over centuries, often as direct responses to fire disasters. Each new disaster highlighted weaknesses, and lessons learned led to regulatory changes in what has been termed ‘stable door’ legislation (with such regulations fixing a particular problem ‘after the horse has bolted’, but not necessarily addressing more systemic failings).

Starting towards the end of the 19th century, these pragmatic responses to fires were supplemented by testing, both in situ in buildings, and in laboratories and specialised testing facilities. This resulted in fire safety regulations that were increasingly detailed,

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eventually constituting comprehensive sets of buildings codes that provided prescriptive rules to be applied according to the type of building and its use. For example, although there are variations between jurisdictions, a typical prescriptive requirement would be for a high-rise building to have a protected, enclosed stairway with a specified level of ‘fire resistance’ for both the stair structure and the doors. The pragmatic nature of such measures can be seen in the way that ‘high-rise’ was typically defined as ‘a building beyond the reach of aerial ladder equipment’ (Brannigan and Corbett 2008, 264), something that could vary between fire services.1

However, many jurisdictions now allow an alternative to prescriptive rules (Alvarez et al 2013). Whereas prescriptive regulation emerged as a response to evidence from fire disasters supplemented by data from testing and generalised analysis, the new approach is justified by a growing belief in the ability to understand the fundamental phenomena of fire and smoke dynamics, the resulting structural responses, and human behaviour in fire incidents. Instead of prescribing requirements (such as levels of ‘fire resistance’ for particular parts of a building, distances to exits, enclosed stairways, sprinklers, etc), the new approach instead requires engineers to demonstrate performance outcomes for a project, and is thus typically referred to as Performance Based Design (PBD). Regulatory approval is based on scrutiny of the design plans; in the case of prescriptive regulation the regulator can check that all features necessary for that type of building have been incorporated in an appropriate way, but in the case of PBD the regulator must be able to understand the knowledge claims made by the designer in order to judge whether their design provides adequate fire safety.

Supporters of PBD fire engineering argue that it enables rational analysis to replace adherence to out-dated and sometimes illogical rules that constrain innovation and add unnecessary costs. However, PBD has also been critiqued by those who see it as part of a neoliberal move towards deregulation. In particular, there is concern that PBD shifts governance of risk from the public to the private sphere if decisions about acceptable levels of safety become a matter for engineers’ design choices rather than being societally mandated in requirements set by government (Brannigan 1999).

The issue addressed here is a specific aspect of this critique, and centres on the challenge of expertise asymmetry posed by PBD regulation. The argument is that expertise asymmetry occurs when regulators have less relevant expertise than those they regulate, and that this may impair the effectiveness of regulation (Spinardi 2016). In the case of fire safety, the shift from prescriptive regulation to PBD raises concerns over the extent to which those

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who approve building designs have sufficient expertise to provide competent oversight of the proposed solutions.

Expertise asymmetry matters because it can skew regulatory practice in favour of industry’s interests to the detriment of wider society, amounting to a specific form of ‘regulatory capture’ (Niles 2002). While prescriptive regulation, like all forms of regulation (May 2007), is susceptible to regulatory capture because industry lobbying can shape the rules that need to be followed, the resulting building codes are open to public scrutiny and typically evolve slowly with most changes addressing observed failures. If anything, the most influential industry lobbies in this regard are those that promote and supply fire safety solutions (such as sprinklers), leading to prescriptive regulations that are increasingly detailed and conservative in nature. In contrast, performance-based regulation relies on local judgments of specific projects (in the case of building fire safety), and depends heavily on whether the approving body has sufficient expertise to ensure that adequate safety is provided.

This is an issue of broad concern for many forms of regulation, as the effectiveness of regulation depends in part on the competence of the regulator to assess that which is being regulated, and this concern is all the more pressing because rapid innovation in science and technology is coinciding with increasing use of ‘light touch’ regulation and a hollowing out of the State in many parts of the world. If this results in regulators having insufficient expertise to do their job effectively then this calls into question ‘the idea that pro-business deregulation was not merely in the commercial interests of industry, but ultimately for the greater good’ (Davis and Abraham 2013, 6).

This paper draws on interviews and ethnographic observation with fire safety scientists, engineers and regulators, as well as the extensive fire safety technical literature, to address the challenges posed by the changing role of expertise in fire safety regulation through an analysis of regulations in England, the USA, New Zealand, and Australia.2 After first discussing some conceptual issues with regulation, what follows describes the types of knowledge used in PBD regulation, and highlights the challenges they present for regulators. Three key questions are addressed. First, to what extent is expertise asymmetry a challenge for PBD regulation of fire safety? Second, what are the implications of varying levels of expertise amongst key stakeholders, particularly fire safety engineers and regulators, given the societal and epistemological challenges involved in determining what is adequate fire safety? Third, given this context, would it be desirable to rely on professionalisation of fire safety engineering to provide adequate fire safety via self-regulation?

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Finally, it should be noted that the June 2017 Grenfell Tower fire occurred following the initial drafting of this paper. From what we know at present – a definitive account of the regulatory failures involved must await the outcomes of both the Public Inquiry and a criminal investigation – it seems unlikely that Grenfell was a result of the specific issues raised in this paper. The refurbishment of Grenfell, like many similar tower blocks in the UK, is unlikely to have involved the kind of performance-based approach to design and regulation discussed here. However, certain aspects of Grenfell – particularly with regard to regulatory competence and complacency – do appear to have resonance with the findings of this paper, and these will be discussed in the conclusions.

Regulation of Technology and the Problem of Expertise Asymmetry

Regulation of technology raises many issues (e.g. Collingridge 1980; Braun and Wield 1994), but perhaps the most fundamental ones hinge on questions of regulatory expertise (Demortain 2017). Regulation is intended to prevent or limit harmful impacts of technology, but to be effective there must be sufficient understanding of how these impacts occur, and how regulations would ameliorate harmful consequences while sustaining technology’s benefits. Regulators thus need to know about the performance of technology. To what extent does a drug cause side-effects relative to its benefits (Abraham and Sheppard 1999)? Do genetically modified crops risk contamination of natural species (Levidov 2001)? Are planes safe enough to carry passengers (Downer 2010)?

As MacKenzie (1996) notes, such knowledge of a technology’s properties can come from three sources: empirical observation of use or testing; inference from theory; or through communication from trusted experts. In practice, regulatory authorities typically rely on a combination of these sources of knowledge. Evidence is gleaned from usage and testing, with hypotheses, methods of data collection and analysis shaped by theoretical understanding, and expert advice sought to reach consensus about regulatory action. However, this is far from straightforward because every step involved in learning about the properties of technology requires judgment and negotiation to reach this consensus.

At the heart of this process is the need for ‘similarity judgments’ with regard to whether a particular usage, test or theoretical analysis is applicable to the case in question (MacKenzie 1996). Evidence from use would appear to be compelling, but typically its interpretation is complicated by difficulties with data collection and the wide variety of conditions and factors at play. For example, the

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UK system of reporting adverse drug reactions garners low levels of returns and provides data whose interpretation is complicated by the fact that many patients (particularly elderly ones) are taking a cocktail of drugs for a variety of ailments (Abraham and Sheppard 1999, 808). Or, as demonstrated with the difficult decision to launch the fateful Challenger Space Shuttle mission, evidence from use may be limited and insufficiently representative; in this case because previous launches had happened in much warmer conditions than those experienced on January 28, 1986 (Vaughan 1996).

Tests can remove many of these issues by controlling the numbers of variables, standardising test design, and providing comprehensive instrumentation (MacKenzie 1989). However, this necessarily makes tests less like actual practice, and raises the question of whether the tests are sufficiently representative. For example, can a small number of engine tests done in a controlled manner against dead chickens provide data that is a reliable guide to the effect of bird strikes on airliner engines (Downer 2007)? Or, are drug tests carried out on small numbers of mainly young, black men in American prisons able to provide results that can be trusted to apply for medicines that will be mainly used by older, white (often female) Americans (Abraham and Sheppard 1999, 813-14)?

Judgments about similarity, and about the weight given to different types of evidence, are therefore central in the production of knowledge claims about the effects of technology. Regulators rely on these knowledge claims to make decisions about the extent to which a technology poses societal risks, and what actions should be taken to mitigate such risks. Because this knowledge embodies complex judgments, and because of the ‘tacit knowledge’ (MacKenzie and Spinardi, 1995) involved, those within the ‘core set’ (Collins 1985) of specialist practitioners are likely to be seen as the most trusted experts.

However, while those in the core set may have the most relevant expertise, their institutional location may make them more susceptible to commercial and organisational bias. This matters because the ‘facts’ do not simply speak for themselves, but rather are constructed and mediated according to the social interests of the experts involved. Moreover, while discussion of technology’s effects can be framed narrowly in terms of technical performance, regulation usually encompasses judgments of societal attitudes towards risks and benefits. For example, drug regulators must balance not only assessments of drug trial evidence, but also potential benefits versus side-effects. Sufferers of terminal illnesses are not surprisingly more focused on the potential benefits of drugs than on any harmful side-effects (Epstein 1996).

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This all points to a potential problem of expertise asymmetry whereby regulators must rely on expert opinion, and on data or technical analysis, that is mainly provided by the industry that they are seeking to regulate (Slayton and Clark-Ginsberg 2017). For example, in many cases of drug approval the regulators not only rely on drug trial data provided by the drug companies, but also on the adjudication by experts (typically from academia) who have conflicts of interest because they are in receipt of research grants from drug companies and/or are shareholders. Indeed, the regulators themselves may have ‘direct and indirect financial interests in pharmaceutical companies’, potentially resulting in what Abraham and Davis (2009, 590) call ‘permissive regulation’.

Expertise Asymmetry and Regulatory Types

Whether expertise asymmetry matters varies in practice because the extent to which regulators need to understand the performance of technology differs according to the type of regulation. Two main approaches have typically been used in fire safety. Prescriptive regulation – also known as ‘technology-based regulation’ (see Coglianese and Lazer 2003) - focuses on rules, specifying what actions needed to be taken to achieve compliance. These rules are intended to produce a desired level of performance, but in a prescriptive regime the regulator’s everyday focus is on checking compliance with the rules and not on measuring, or predicting, performance outcomes. Thus, the expertise required in the oversight of prescriptive regulations concerns the meaning and application of the rules rather than the nature of the technology itself. The alternative regulatory approach is performance-based regulation that focuses on outcomes, specifying the level of performance that is considered satisfactory. The challenge here is that this type of regulation depends on the ability of regulators ‘to specify, measure and monitor performance, but reliable and appropriate information about performance may sometimes be difficult if not impossible to obtain’ (Coglianese et al 2003, 708).

The ability to measure performance is thus key to a performance based approach to regulation, with a crucial distinction being whether it is considered satisfactory to rely on retrospective measurement of performance or whether prospective performance must be predicted. The first of these approaches to performance-based regulation measures actual outcomes and need not require the regulator to have in-depth knowledge of the processes being regulated. For example, the end-of-pipe effluent regulation used for many years to limit the pollution of rivers and other water bodies depends of knowledge about the harmful effects of the pollutants and on the reliability of measurement techniques, but does not require understanding of the industrial processes involved in producing the pollutants. Typically, if certain levels of pollutants are recorded, either in the effluent discharges themselves or in the

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water body receiving them, this will result in fines, or if judged particularly serious, legal action to stop operations (Clayton et al 1999).

However, such an approach requires tolerance of unsatisfactory outcomes. Whereas it may provide a suitable approach for regulation of effluent from paper mills or breweries (most of whose discharges are only harmful to ecosystems in excessive concentrations), such an approach is necessarily reactive, and not acceptable where high consequence outcomes are possible. It would not be socially acceptable to regulate airliner reliability by measuring the number of crashes and fining the manufacturers or operators accordingly. Catastrophic aircraft failure is infrequent, and regulatory control cannot rely simply on assessing the reasons for accidents, and correcting failings thus revealed (though this does of course happen). Instead, proactive regulation is required in which satisfactory performance is sought by oversight of the processes involved in producing an airliner (Downer 2010; 2011).

Traditionally, regulation of fire safety has operated through enforcement of prescriptive rules because the prospective performance of individual buildings could not readily be assessed. In this prescriptive approach buildings are classified into a range of types according to height, occupancy, usage, and so on. For any particular building type a range of mandated fire safety solutions are set out, specifying, for example, the level of ‘fire resistance’ required for particular parts of the structure, maximum travel distances allowed to exits, the use of protected staircases and sprinklers, etc. The job of the regulatory authority is then to check that the appropriate rules have been followed. To effectively regulate such a prescriptive regime requires the regulator to know what the rules are, and where there is uncertainty, to adjudicate on which rules are applicable and what the rules are intended to achieve. Buildings approved on the basis of these prescriptive rules are generally perceived to be ‘safe’ on the basis of the historical track record of buildings so approved, with an accumulation of new measures as response to disasters that exposed failings, and an underlying assumption that the rules provide large margins of safety in most cases.

Prescriptive fire safety regulation remains commonplace in most jurisdictions, but recent decades have seen increasing use of a performance-based design approach. This change has mainly come about due to dissatisfaction with the limitations of prescriptive regulation, along with the belief that fundamental understanding of fire dynamics and structural behaviour has become good enough to enable prospective assessment of fire safety. However, this shift raises questions not only about how the desired level of

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performance is determined, but also about whether regulators have sufficient expertise to adjudicate on whether it has been achieved.

What follows first briefly describes how prescriptive fire safety regulation developed before detailing the move to PBD regulation in four jurisdictions – England, the USA, Australia and New Zealand. These differing implementations and experiences of PBD provide comparative insights into the challenges faced in providing competent regulatory oversight with a performance-based approach.

Prescriptive Fire Safety Regulation

Fire was a pervasive problem in early cities where closely co-located buildings made of flammable materials meant that fires often spread rapidly and caused widespread destruction (Arnold 2005). For example, the Great Fire of London in 1666 burned over two-thirds of the city, destroying 13000 homes. As a result, fire insurance companies were formed, fire-fighting units set up, and new building regulations promulgated (Porter 2009). The Rebuilding of London Act 1666 set out detailed building regulations, requiring that brick or stone should be the main building materials, and setting out specific requirements for a range of measures including the width of walls (including shared ‘party walls’) according to the type of dwelling (Knowles and Pitt 1972; Ley 2000).

London’s experience was repeated around the world as fire disasters in other cities produced similar responses. These pragmatic responses initially used broad-brush solutions based on observation of real fires. However, towards the end of the 19th century increasing attention was paid to gaining better understanding of the characteristics of fire and the ability of certain types of building materials and structures to withstand it. In particular, the concept of ‘fire resistance’ was formalised, and standardised testing procedures adopted to enable comparison of the ‘fire resistance’ of different materials and structural elements (Babrauskas and Williamson 1978a; 1978b).

This furnace testing is not fully representative of real-world fires, but it enables comparison of materials and structural elements of different types and from different manufacturers. Test results that show, for example, 120 minutes ‘fire resistance’ in a furnace do not mean that the test sample would necessarily last the same time in a real fire, but they do allow materials and structural components to be certified as having a suitable (approximate) level of ‘fire resistance’ for the types and parts of buildings where this was deemed necessary.

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Standardised tests thus provided a mechanism by which crude measures of fire resistance, such as party walls needing to be one or two bricks thick (as set out in the Rebuilding of London Act), could be quantified into more comparable measures such as 120 minutes of fire resistance. Thus calibrated, performance ratings derived from standard furnace testing provided a rough functional equivalence metric and complemented regulation based on prescriptive requirements derived from historical events. So long as buildings remained more or less the same with only incremental changes then prescriptive requirements that specified performance based on standard testing could usually provide adequate safety. When unexpected fire disasters revealed weaknesses in these regulations, new prescriptive requirements were added.

Such historic building codes have served societies well in reducing fire damage and deaths, with a focus on four main issues to ensure life safety: (1) evacuation; (2) fire and smoke containment; (3) fire-fighting access and facilities; and (4) structural performance.3 By the late twentieth century there were many building codes geared towards ensuring fire safety, typically organised according to classes of building (with more stringent requirements for high-rise or high-consequence constructions). These codes are usually enforced by local government officials whose role is to check that all relevant requirements for a building design have been met. Such enforcing authorities cover all aspects of building design, and would not typically have any specialist fire safety education, although in many jurisdictions the fire services are also consulted in the design approval process.

The prescriptive approach came under fire for inhibiting innovative architecture and imposing sometimes irrational, unnecessary and expensive requirements (in part because of the perceived large margins of safety for many buildings). For example, by the end of the 1970s the building regulations for England and Wales totalled 307 pages of guidance, and were described as being ‘very prescriptive and understood mainly by lawyers’ (Law 1991, 263). American fire safety code proliferation continues unchecked, with the main fire related volume of the International Building Code amounting to over 700 pages. Many fire engineers operating in the US thus describe their role mainly as that of ‘code consultants’ rather than engineers.4

Prescriptive codes also comprise a patchwork of requirements that has evolved over many years, with the rationale for many of these requirements appearing dated, and with quantitative requirements – what Law and Beever (1995) refer to as ‘magic numbers’ – set out without explicit scientific or engineering explanation. For example, the UK requirement for a maximum reversing distance of 20m for fire tenders is said to have its origins in the ‘maximum distance

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that horses pulling pumps could reasonably be encouraged to reverse without excessive use of a whip’ (Bullock and Monaghan 2014, 25).

Moreover, a prescriptive regulatory approach based on direct experience of fire disasters has obvious limitations if innovation in building materials (e.g. increasing use of plastics and other petrochemical materials) or architectural design calls into question the validity of that experience. In his inaugural speech, on 14 November 1974, the new Professor of Fire Safety Engineering at the University of Edinburgh, David Rasbash described the problem thus:

… we cannot continue to rely on the time honoured method of the past in dealing with fire safety, i.e. to rely on experience painfully built up and the passage of decades, if not millennia, for lessons to be learned, sink in and acted upon. Direct experience is becoming too painful a teacher ..5

The alternative approach proposed by Rasbash was to generate fundamental knowledge that could be used to predict the fire safety performance of a building design. Thus, recent decades have seen the prescriptive approach to fire safety regulation complemented in some jurisdictions by a regulatory approach based on assessment of prospective performance.

The Shift to Performance Based Design

The availability of PBD as a regulatory option addresses the dissatisfaction with the perceived ‘one-size-fits-all’ approach of prescriptive regulation, and builds on the belief that fundamental fire safety knowledge has progressed sufficiently to enable bespoke fire safety engineering solutions to be designed and assessed. According to the definition of the International Organization for Standardization (ISO/TC92/SC4) fire safety engineering is: ‘The application of engineering principles, rules and expert judgment based on a scientific appreciation of the fire phenomena, of the effects of fire, and of the reaction and behaviour of people, in order to: (a) save life, protect property and preserve the environment and heritage. (b) quantify the hazards and risks of fire and its effects. (c) evaluate analytically the optimum protective and preventative measures necessary to limit, within prescribed levels, the consequences of fire’ (quoted in Ramsay 1996, 105).

PBD fire safety engineering can enable the use of innovative building designs and materials, and allow the use of constrained or usually shaped sites, that strict compliance with prescriptive rules would inhibit. In many cases PBD may also allow more fine-tuned fire safety solutions that are cheaper than those mandated by

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prescription (although such savings must be balanced against the likelihood that prescriptive solutions will be approved faster than PBD solutions). Such fine-tuning is a central methodology of engineering practice, with the safety of the resulting designs dependent on judgments about the desirable margin of safety and the reliability of the chosen epistemological basis of the calculations and their robustness in the face of operational conditions (Petroski 1992).

Implementation of PBD has varied greatly, with different approaches adopted in different jurisdictions. While fire safety engineering can provide a more rational approach than prescriptive rules, the shift to PBD is also associated with the deregulatory, neoliberal politics that became mainstream in the Reagan/Thatcher era. Much has been written about how privatisation of regulation can improve ‘efficiency’ (for a summary see van der Heijden 2010), but there has been less scrutiny over whether such regulation is also ‘effective’ (e.g. in maintaining safety performance).

Building control was one of the many aspects of governance with which the Thatcher government pursued its deregulation agenda in the UK, with a 1981 Command Paper on The Future of Building Control in England & Wales setting out key objectives of ‘maximum self-regulation’ and ‘minimum Government interference’ (HMSO 1981, 4). This led to the 1984 Building Act that enabled the use of PBD as a way of meeting the functional requirements outlined in the resulting Building Regulations. These functional requirements focus on escape, structural performance, fire spread and fire fighter access and are expressed largely in subjective terms with the use of words such as ‘adequate’, ‘satisfactory’, and ‘sufficient’. For example, the first of the five functional requirements is: ‘To ensure satisfactory provision of means of giving an alarm of fire and a satisfactory standard of means of escape for persons in the event of fire in a building.’ The regulations require that the functional requirements are met, which in practice can be done by adherence to the prescriptive guidance provided in Approved Document B. However, a PBD approach can also be used to meet the functional requirements. Approved Document B states that ‘there is no obligation to adopt any particular solution contained in an Approved Document if you prefer to meet the relevant requirement in some other way’, whilst also noting that fire safety engineering ‘may be the only practical way to achieve a satisfactory standard of fire safety in some large and complex buildings’ (Approved Document B, Vol. 1, 10-11).

New building regulations introduced in New Zealand and Australia during the 1990s also endorsed neoliberal deregulation. In New Zealand, this was characterised as ‘a period when the market extremists were still triumphant, and there was frequent reference

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to “light-handed regulation”, referring to a regulatory system in which the government is not very active but regulation is based on normal market practices, including litigation for breach of contract’ (Easton 2010, 44). The New Zealand Building Act 1991 set out comprehensive national buildings regulation, including a performance-based approach (Mumford 2010; Buckett 2014). Similarly, a performance based building code was introduced by the Australian Building Codes Board in 1996 (Beck 1997). These New Zealand and Australian regulations were broadly similar in outline. Prescriptive requirements remained as an option, known as ‘acceptable solutions’ in New Zealand and ‘deemed-to-satisfy provisions’ in Australia, but both regimes enabled the use of PBD in what were termed ‘alternative solutions’.

Fire safety regulation is not under national government control in the USA, but over the years various standard setting organisations have produced different codes with local jurisdictions free to choose whatever code they preferred to apply. The three regional code organisations merged during the 1990s to form the International Code Council and a single national model code, known as the International Building Code (IBC), was produced in 2000. The IBC is now widely used, though typically with local modifications made both by states and by counties or cities (and some jurisdictions use the Life Safety Code Handbook of the National Fire Protection Association).

Within the IBC, PBD fire engineering is enabled by section 104.11 ‘Alternative materials, design and methods of construction and equipment’ which allows alternatives to the prescriptive code ‘where the building official finds that the proposed design is satisfactory and complies with the intent of the provisions of this code, and that the material, method or work offered is, for the purpose intended, at least the equivalent of that prescribed in this code in quality, strength, effectiveness, fire resistance, durability and safety’. The IBC option to use PBD is thus explicitly based on ‘equivalencies’ with the prescriptive code.

Performance Based Design in Operation – Defining the Level of Safety

Whereas prescriptive regulation simply involves following the rules for a building’s fire safety design (mainly according to size and usage), PBD regulation requires a two stage process.6 First, it must be decided what level of fire safety performance is required. Second, this defined level of safety should be demonstrated to the satisfaction of the approving authority (the Authority Having Jurisdiction or AHJ).

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One way of setting the performance requirement is by ‘equivalence’ to the prescriptive guidelines, with the codes ‘usually treated as the starting point … due to regulatory authorities “comfort” with the “magic numbers”’ (Bullock and Monaghan 2014, 26). Using equivalence as a basis for approval has the advantage that the prescriptive guidelines provide a benchmark for the ‘revealed preferences’ of what society considers tolerable with regard to fire risks (Wolski et al, 2000). Although the prescriptive rules may be as much the result of politics and historical accident as of rational analysis, they clearly have generally been effective, and are accepted as providing adequate safety in most cases. In addition, for the AHJ (typically local government building control officers, often working with the fire services) this approach has appeal because these regulatory authorities have relevant expertise in so much as they are familiar with the prescriptive rules, and what a code-compliant building, designed according to these rules, should look like.

However, demonstrating equivalence can be difficult because the prescriptive guidelines are not written in terms of specific performance; they say what to do, but not what performance will be achieved by doing it. This presents a challenge because a strict requirement to demonstrate equivalence depends on quantification of the performance outcomes of the prescriptive approach so that the PBD solution can be compared and judged as to whether it has reached this level. For example, in the US IBC the requirement for approval is that the AHJ should judge a PBD solution to be ‘at least the equivalent’ of the prescriptive code. As one US regulator put it: ‘The code’s prescriptive design, we have to use that as a base. And then whatever performance design that you come up with you have to prove the equivalencies. But equivalency cannot be diminishing the prescriptive requirement, you have to be equivalent or better.’7

This poses a challenge for US regulators because of the difficulty of quantifying the performance of the prescriptive design. Thus, a paper written by fire engineers and San Francisco Fire Department officials notes that: ‘Performance-based code requirements are often void of defined benchmarks, opting for a loose description of design objectives that are to be achieved. This ambiguity may provide insufficient direction to an AHJ attempting to discern the basis for approving a design submittal.’ This means that: ‘The further building codes move towards the utilization of performance-based rather than prescriptive design criteria, the more difficult it will become for an AHJ to evaluate what constitutes an acceptable design. … The review process may become prolonged as a result, impacting construction schedules and project timelines’ (Ferreira et al 2002, 52).

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This strict interpretation of equivalence means that the option to use PBD is infrequently invoked in most US jurisdictions because the challenges it poses to regulators increases the risk of delaying approval and increasing costs. According to one San Francisco fire safety engineer: ‘Perhaps 95% of projects are just follow the code, follow the prescriptive code.’8 Only projects that are so bespoke that they do not fall readily within the remit of the codes (such as sports arenas, transportation infrastructure, or ‘statement’ buildings) are likely to justify the use of PBD in the USA. Las Vegas, with its particular history and building requirements, is perhaps the only jurisdiction where bespoke buildings (typically large casino hotels) have been so common that approval of PBD fire safety solutions can be considered routine.9 Ironically, although the IBC formally includes the option of using PBD, the practice of fire safety regulation in the USA has if anything become more prescriptive because the codes have become increasingly comprehensive (perhaps because of the influence that the suppliers of prescriptive solutions have in code committees10).

In the other three jurisdictions considered here, the standard for equivalence is not so explicit, and so assessment of whether a design is equivalent to the prescriptive approach is more flexible. For example, in England, the only requirement is that the five (largely subjective) functional requirements are met, although this is typically judged by equivalence to the perceived intention of Approved Document B. A common context for invoking equivalence is when a project is mostly prescriptive in nature, but incorporates some PBD for the purposes of ‘solving a problem with an aspect of the building design which otherwise follows the provisions in this document’ (Approved Document B, Vol. 1, 11). This may be done because the designer believes the prescriptive approach is flawed for their project, but is also done in order to overcome site constraints, add value, or provide a ‘sticking plaster’ solution to enable a design to be approved in a case where fire safety issues were not addressed sufficiently early in the project.

A typical example would be a building squeezed into a tight plot where there is a premium on maximising the usable floor space. Prescriptive guidance (e.g. Approved Document B) specifies maximum travel distances from rooms to exits, but adhering to those travel distances can require allocating more space to corridors and stairways than commercially desirable. A common solution is to install a smoke control system that is deemed to keep the evacuation route tenable for longer. The tenability conditions implied by Approved Document B can be reverse engineered to provide a benchmark, and then fire and smoke development modelled for scenarios involving the smoke control system. The AHJ can then adjudicate as to whether the proposed solution

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achieves the same level of safety as implied by Approved Document B, and thus meet the functional requirements.

However, equivalence is not the only way that performance requirements for a project can be set. The alternative to deriving benchmarks from prescriptive guidelines is to use a ‘first principles’ approach to set performance requirements for a specific project based on the general requirements set out in building regulations. For example, the key functional requirement in England to provide ‘a satisfactory standard of means of escape for persons in the event of fire in a building’ can be demonstrated through an analysis of the project that calculates Available Safe Egress Time (ASET) and Required Safe Egress Time (RSET). Simply put, ASET is the length of time for which the conditions in a building will remain tenable following the start of a fire, with smoke usually being the limiting factor - although temperature or structural blockage/collapse are also potential concerns. RSET is the time calculated for an occupant to respond to being alerted to a fire, make a decision to evacuate, and then to carry out that evacuation. A building is liable to be deemed to attain a satisfactory level of fire safety with regard to evacuation if RSET is lower than ASET with a reasonable margin of error.

However, there have been concerns, particularly in New Zealand and Australia, that the first principles method has led to wide variations in approach. Thus Fleischmann (2011, 92) notes that: ‘The parameters used within a performance-based design such as the design scenarios, design fires and acceptance criteria are suggested by the designer with the acceptance of the AHJ, which can lead to inconsistent levels of safety being achieved for the design of similar buildings’. As one New Zealand fire safety engineer put it, ‘designing from first principle lacked any certainty of outcome due to there being no fixed performance criteria. Outcomes varied dependent on the opinions and experience of the peer reviewers meaning that just because a design was approved once it did not necessarily follow that it would be approved again in the future’ (James n.d.).

For example, to return to the key issue of evacuation during a fire, the most fundamental requirement is that conditions in exit routes remain tenable for a sufficient time. However, the definition of tenability varies greatly between jurisdictions, and potentially between different regulators. A recent survey of tenability criteria in 14 countries noted variations in acceptability criteria with smoke layer height varying between 1.9 and 3.5m, temperature between 50 and 200°C, carbon monoxide levels between 180 and 4000ppm, and radiant heat flux between 2 and 10 kW/m2 (Levy and Martin 2015).

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The use of PBD thus poses expertise challenges for regulators, whether they seek to set performance requirements by equivalence or by reference to a first principles definition of the level of safety. Whereas traditionally regulators needed expertise in the interpretation and application of rules (still the norm in the USA), the use of PBD calls for expertise in translating prescriptive rules into performance metrics or in establishing performance metrics from first principles. The difficulty involved in these processes means that, according to Alvarez et al (2013, 252), ‘the selection of acceptance criteria and design fire scenarios is more a “collegial political” choice than an outcome of a real characterization and treatment of fire risk in the building’. Perhaps even more significant, however, is that effective regulation of PBD requires regulators to have expertise in understanding the specific knowledge claims that engineers make about how this performance is achieved.

Performance Based Design in Operation – Demonstrating Performance

For a PBD fire safety solution to be approved, the regulatory authority should be convinced that the fire safety engineer has demonstrated the required level of performance, whether that is based on equivalence or on first principles derivation from functional requirements. Engineers will typically make their case by quantifying the key properties of the building and its contents and occupants, and then calculating a number of relevant processes with regard to fire and smoke spread, structural response, and human behavior – ideally over a range of appropriate scenarios. A PBD approach to fire safety will thus be based on calculations that are claimed to show that the building will meet the defined level of fire protection with regard to evacuation, limiting fire spread, structural behaviour, and fire fighter safety. Most regulations focus on life safety, but similar calculations can be done with an emphasis on providing property protection or resilience of business operations.

This demonstration of performance is typically based on knowledge claims derived from the modelling of phenomena such as fire development, smoke spread, structural response, and evacuation times. Simple calculations may be sufficient to convince regulators that the margins of safety are so clear that more complex calculation is unnecessary, but it is becoming commonplace to use techniques such as computational fluid dynamics (CFD) modelling to simulate the development and spread of fire and smoke. Although it is not the only CFD model available, the Fire Dynamics Simulator (FDS) software, developed by the US National Institute for Science and Technology (NIST), is the most widely used. NIST also produce the Smokeview visualisation program that provides graphical display of FDS outputs. Software such as FDS/Smokeview thus enables fire safety engineers to model a building design to

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calculate the fire development and smoke movement that would result from various fire loads in different positions. Although such modelling can be computationally time-consuming, this means that engineers can readily ‘demonstrate’ the performance of different design options.

Similarly, structural behaviour of buildings can be modelled using, for example, finite element modelling that enables simulation of the behaviour of steel structures with different levels of fire protection. Engineers can thus design innovative structures that do not comply with prescriptive guidance, and can fine-tune structures to economise on fire protection (which steel requires because it loses strength at temperatures that are typical of many fires). Likewise, a number of different models with varying levels of complexity are used to simulate evacuation behaviour. Thus, for some projects, three types of models may be used to make the case for the overall fire safety design.

This use of modelling poses a significant challenges for regulators with regard to expertise asymmetry. Not only are building approval regulators unlikely to be up to date with the state-of-the-art fire science that some engineers may draw on, but also they may be unfamiliar with the idiosyncrasies of the various models that embody this science. Most regulators lack the expertise to replicate or even competently interrogate the modelling efforts of fire safety engineers, or to assess the validity of the underlying science or its applicability to the design. This is important because, while the performance of such models for some circumstances has been validated by laboratory tests, they are notoriously dependent on user-competency. Thus Johansson (2014) notes that ‘the user has been found to be the most critical link in the chain of simulations.’ Likewise, with finite element modelling of structural responses to fire, there is concern that model users may be unaware of the limits of their competence: ’Someone who is trained classically as a structural engineer, who’s then told to run a finite element model on a building under fire, who doesn’t know anything about fire dynamics or heat transfer or thermal deformations or how materials soften, they’re just going to take the input data that they’re given, they’re going to run the analysis, looks reasonable, fine. They don’t know that they should be thinking harder about this stuff, they’re not competent to know where their competence ends.’11 Much depends on the initial model choices and assumptions made by the model user, and effective regulation would require regulators who are well versed in the intricacies of the various types of models used for fire and smoke dynamics, structural responses, and evacuation behaviour.

User competence is crucial because of the complexity and probabilistic nature of fire safety phenomena. Models are typically

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validated against experiments (themselves ‘models’ of actual building fires), and so care must be taken in claiming that this validation extends to more complex ‘real world’ scenarios. As Johansson (2014) observes: ‘Compartment fire dynamics are complex and can only be described analytically with simplified theories due to the random behaviour of fires and flames.’ The representativeness of other types of fire safety models, such as evacuation models, is even less well understood because ‘few validation studies have been performed, mainly because of the lack of real world data available’ (Ronchi and Nilsson 2013, 17).

That models are not guaranteed to reveal ‘real world’ performance does not of course mean that they are not worthwhile if used judiciously. However, as Gobeau and Zhou (2004, iii) note: ‘Despite a lack of validation for this application, CFD is increasingly used in safety cases as a predictive tool to demonstrate the effectiveness of modern building designs and/or emergency ventilation to control the movement of smoke in the event of a fire.’ Amongst the challenges for CFD model users is that ‘when creating a model the CFD practitioner has to make assumptions and select “appropriate” parameters’ (Gobeau and Zhou 2004, 33). As with grid models in general (see Edwards 2010 on climate change models), the resolution chosen can be critical, but it is ‘quite often difficult to foresee what may be an appropriate resolution for the mesh’ (Gobeau and Zhou 2004, 33).

It is clear, therefore, that the models widely used by fire safety engineers to gain regulatory approval depend heavily on user competence, and produce results that may not be representative of ‘real world’ fires. As Gobeau and Zhou 2004, iii) found, in the examples in their investigation, ‘CFD modelling approaches provided results that looked realistic’, but ‘a comparison of quantitative data; such as the temperature of the hot layer, the depth of the smoke layer along the ceilings, and the rate of propagation of smoke, showed that these key parameters can vary significantly – depending on the modelling approach used.’ This conclusion was supported by a large-scale 2006 fire test that also demonstrated the limited predictive power of fire models. In a test performed in an unoccupied tower block in Dalmarnock, Glasgow, a flat was instrumented, furnished realistically, and a fire initiated and allowed to progress. Seven different research groups were given the same starting conditions for the test and asked to blindly model its subsequent behaviour. The results varied widely, even though most teams used the same simulation software (FDS). With regard to the Heat Release Rate (HRR), only one simulation provided ‘a reasonably good prediction’, with another 100% over, and the rest under-predicting the HRR ‘in the range of 30-90%’ (Rein et al 2009, 598). It was concluded that ‘current modelling cannot provide good predictions of HRR evolution (i.e. fire growth)

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in realistic complex scenarios’ (Rein et al 2009, 601). Other round robin exercises have had similar results (e.g. Ekholm 2015).

This presents a major challenge for regulation if AHJs lack the expertise to interrogate the use of models that are claimed to demonstrate the performance of fire safety designs. As Johansson (2014) notes: ‘Many fire models are easy to obtain and easy to use, this means that they can be used in a careless or incorrect manner. This is problematic, because errors due to misuse can be difficult to discover.’ Because ‘the sensitivities to the modelling approaches are not always evident a-priori’ it is ‘strongly recommended that a set of CFD simulations be undertaken, rather than a one-off case; which could be misleading.’ (Gobeau and Zhou 2004, v). Responsible fire safety engineers who are aware of the limitations of modelling will thus typically carry out a range of simulations rather than rely on a single scenario. The choice of these scenarios is crucial, as was noted in the Fire Protection Handbook of the US National Fire Protection Association: ‘If only a few scenarios are modeled explicitly, then each one is implicitly required to be representative of a much larger and more varied collection of other scenarios. There may be no good evidence to support this’ (Hall and Watts 2008, quoted in Alvarez et al 2013).

The regulatory challenge is particularly significant because the rationale for PBD is to provide bespoke fire safety solutions for buildings that are not only effective but also efficient. Fire safety engineers thus seek to fine-tune their designs to provide the most efficient solution that will gain regulatory approval, whilst being compatible with other engineering aims such as structural and environmental performance. However, the more that fire safety designs are fine-tuned, the more important it becomes that practitioners (both engineers and regulators) understand the limits of their knowledge and the appropriate margins of safety to apply.

Expertise Asymmetry or Expertise Deficit?

Effective regulation of PBD fire safety solutions thus appears to depend on the approving authorities having sufficient understanding of the underlying knowledge claims that are often based simulation model outputs. However, day-to-day building regulation is typically done by local government personnel whose role has traditionally been to apply prescriptive guidance that covers all aspects of building design, and who will rarely have had specialist fire safety education. Such approving authorities are thus not well-equipped to understand and interrogate the knowledge claims used in PBD fire safety design, and there is particular concern that many regulators lack the expertise to understand the limitations of the modelling tools that are frequently used. For regulatory authorities this challenge can be exacerbated by the way that engineers present their results, as the high quality graphical

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outputs of some models may create a misleading impression of verisimilitude. Thus one US regulator unconsciously appeared to reveal his lack of understanding when he noted that ‘our computer simulations are getting much, much more powerful. We can do simulations we can see actually in a motion format, we can see where the smokes goes, so it’s pretty exciting, the technology that we have.’12

Concern about the implications of expertise asymmetry for fire safety design approval is widespread (e.g. in the Australian Building Products Innovation Council’s April 2018 report Rebuilding Confidence: An Action Plan for Building Regulatory Reform). In general, US regulators have limited the use of PBD because of doubts about whether they have sufficient competence. In England the use of PBD for fire safety is more variable. Some regulators are reluctant to approve designs because they lack confidence that they fully understand the arguments being made, instead preferring a prescriptive approach. Other regulators feel more confident in their understanding, or are more willing to trust the engineers. PBD has become commonplace in some jurisdictions (notably Central London) where regulators have become familiar with the use of fire engineered solutions, and believe they have the competence to judge whether the functional requirements have been satisfied (and funding levels mean that they can employ specialists in fire engineering). On the other hand, some regulators may approve designs without proper scrutiny because they are reluctant to reveal their ignorance.13

One approach to addressing the expertise asymmetry issue for specific projects is to seek outside review. The more challenging projects can be handled through the use of such reviews (if the regulator is sufficiently aware of their own limitations to request such a third party review), although finding a competent and unbiased reviewer may be difficult in practice because fire safety PBD draws on three complex and rapidly evolving disciplines. However, more modest use of PBD in mainly prescriptive projects may attract less scrutiny. In particular, the use of CFD modelling of smoke control to allow longer travel distances has become commonplace, with the approval of earlier projects seen as setting precedents that make further approvals routine.14

Whereas lack of regulatory expertise has limited the use of PBD in much of the USA and some English jurisdictions, the more open-ended approach to defining performance requirements in New Zealand and Australia may have allowed PBD to be used without sufficiently critical oversight. In both nations the introduction of PBD was part of a process of deregulation, intended to reduce costs and promote innovation, and accompanied by other measures that impacted on regulatory oversight. The result, as summed up by a

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fire safety engineer in New Zealand, was that there were ‘no restrictions on who can carry out a fire risk assessment … This range of competencies tended to drive down the quality of work to the lowest common denominator as clients that needed to engage a fire engineer would often select a consultant on the basis of price rather than competency’ (James, n.d.).

This points to a more profound concern with the use of PBD in fire safety regulation; that there is not simply expertise asymmetry between engineers and regulators, but also a more general expertise deficit amongst all participants. Modelling software packages developed by fire safety scientists have been adopted by engineers as design tools, but, as detailed above, care is required to ensure that such software is used in an appropriate manner and that the outputs are representative for the building in question. Lacking such expertise, there is a risk that fire safety designs may be proposed and approved without a good understanding of potential weaknesses.

Several solutions have been proposed to address the expertise asymmetry problem posed by the use of PBD, but it is important to also consider how such solutions deal with the issue of the broader expertise deficit amongst fire safety engineering practitioners. One obvious solution to expertise asymmetry is to increase the expertise of regulating authorities so that they have the competence to provide adequate oversight - as suggested in the case of cyber security regulation by Slayton and Clark-Ginsberg (2017). For example, deliberations over the state of Scottish building regulations following the Grenfell Tower fire have raised the idea of a ‘central review hub’ for ‘complex and high-risk buildings’, with the logic being that appropriate expertise could be brought to bear on these more challenging cases of PBD.

However, local authority regulators would still need to have sufficient expertise to know which projects to refer to such a central hub, and such an approach would only be feasible in jurisdictions with small numbers of PBD projects. In a world where government finances are strained, it may be unrealistic to expect the problem of expertise asymmetry to be addressed by increasing the expertise of the large numbers of design approval authorities who operate in local jurisdictions. Without a major reversal of the deregulatory trend of recent decades, it thus seems a forlorn hope to equalise the expertise asymmetry by upgrading the expertise of local building control regulators (although some improvement in capacity is both possible and necessary). Some jurisdictions (such as London and Las Vegas) with many major PBD projects and a strong revenue base already have the capacity to provide regulatory oversight, but this will be expensive to ensure more widely.

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Instead, there are two other approaches that accept that expertise asymmetry is inevitable, but seek to ensure that PBD fire safety regulation nevertheless provides societally satisfactory outcomes. First, it has been proposed that a more narrowly constrained approach to PBD (sometimes referred to as ‘prescriptive PBD’) can provide standardised metrics that facilitate regulatory oversight, and such an approach has been pioneered in New Zealand (see next section). Second, it can be argued that the expertise deficit amongst fire safety engineers is the real problem, and that the expertise asymmetry would be less significant if engineers could be trusted to be both competent and ethical.

Leaky Buildings and Prescriptive PBD

Concerns about the use of PBD came to a head in New Zealand because of a scandal with building construction, though not one directly related to fire safety (Buchanan et al 2006). In the mid-1990s, after the introduction of PBD building regulation, many houses were built in a style – known as monolithic-clad or Mediterranean-style – that proved unsuited to New Zealand climatic conditions. By 2002 it was clear there was a crisis, prompting government inquiries (May 2003; Easton 2010). Amongst the factors identified ‘was a race to the bottom in building approval standards especially as they related to alternative designs’ (May 2003, 395). The ‘leaky buildings’ crisis provided clear evidence that the PBD regulations provided poor regulatory oversight. The problem was that ‘de facto standards for performance of cladding systems were established by the marketplace, with those standards falling short of what was intended by the performance-based code’ (May 2003, 398).

Reform followed, seeking to address a range of factors perceived to have contributed to the ‘leaky buildings’ crisis, including ‘clearer definition of performance standards in the Building Code’ (May 2003, 396). A revised building code was introduced in 2013. In order to reduce the potential for inappropriate and inconsistent outcomes the new fire safety regulations specify both the inputs and outputs for PBD in a rigidly prescribed framework (Wade et al 2007). The aim was to reduce reliance on negotiation and judgment, and to instead have standard approaches, and measurable outputs that provide a more consistent level of fire safety.15

The resulting document - ‘C/VM2 Verification Method: Framework for Fire Safety Design’ – sets out ten design scenarios ‘that must be considered and designed for, where appropriate, in order to achieve compliance’ (Ministry of Business, Innovation & Employment 2013, 11). Presented as ‘decision trees’, some of these design scenarios set out options that amount to prescriptive

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requirements - for example, to require a second escape route for certain buildings, or to require certain types of fire detection and alarm systems. Others require that analysis – particularly ASET/RSET – be carried out in a certain way, using specified input data and performance criteria. This use of verification methods has been described as ‘prescriptive PBD’. It is argued that it provides clear compliance methods, thus ‘removing the existing scope for interpretation and dispute’, and aims ‘to lead to greater consistency of fire design, greater certainty and reduced compliance costs for the industry, and a design process that is more efficient’ (Fleischmann 2011, 92).

Similar concerns with the quality of regulation in Australia has led to the Australia Building Codes Board to also develop quantitative verification methods, with the expectation that for fire safety these will be based on New Zealand’s C/VM2. Verification methods are also at the heart of the PBD option in new Italian fire safety regulations16, and are under consideration in Scotland.17 The use of verification methods is intended to address the challenge of expertise asymmetry by limiting the open-ended nature of PBD. Rather than fire safety engineers being able both to define the performance level of a fire safety design and then choose their own methodology to demonstrate that performance level, the verification methods approach limits the criteria and methodology involved. However, this ‘prescriptive PBD’ approach does not address the key problem of the expertise deficit by ensuring that regulators and fire safety engineers have adequate expertise levels.

Indeed, the formulaic application of design scenarios constitutes a return to a rule-following approach rather than requiring engineers to think through their designs and be more competent in the application of their discipline. Engineers can design on the basis of verification methods, and regulators can approve such designs, but following these methods by rote does not mean that either party has fully understood the performance of the resulting fire safety solution. Verification methods thus provide a solution of sorts to expertise asymmetry, but without addressing the expertise deficit problem.

Moreover, the use of a limited number of design scenarios has the familiar problem of prescription in that it may work adequately for common building types, but be inappropriate in some instances. However, if regulators and engineers have not improved their expertise they may be unable to recognise those instances. Indeed, it can be argued that the existence of verification methods removes the requirement for engineers (and regulators) to acquire further expertise; the ability to work to the requirements of regulations such as C/VM2 now becomes the only expertise necessary.

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Trust in Professionals?

An alternative approach to requiring PBD to be carried out prescriptively would be to trust fire safety engineers to be competent and ethical; in other words, to rely more on self-regulation by professional engineers rather than on the detailed oversight of regulators. Critics (e.g. Perrow 2015) may have good reason to be sceptical of the claims made by advocates of self-regulation in many areas, but such an approach would acknowledge the issue of expertise asymmetry in PBD by explicitly placing responsibility on the fire safety engineer. This kind of delegated regulation is found in aviation where the US Federal Aviation Administration (FAA) has long recognised that it could not maintain the expertise to regulate certification of new aircraft technology. Only those involved in the development of aviation technologies have sufficient knowledge to judge what is safe or not. For this reason the aviation industry largely self-regulates because the FAA delegates much of the task to industry employees known as Designated Engineering Representatives. Downer (2010, 84) thus argues that in this case ‘high-technology regulators contend with an intractable technical problem by turning it into a more tractable social problem, such that, despite appearances to the contrary, the FAA quietly assess the people who build aeroplanes in lieu of assessing actual aeroplanes’.

Regulation of structural engineering already operates in a similar manner. Structural engineering designs are typically not subject to detailed examination by regulators; rather structural engineers are trusted to be competent professionals (with peer review often used to check the approach and calculations18). It is the people, not their work that is regulated, and this regulation takes the form of accreditation of structural engineering as a profession. Although the specifics vary between jurisdictions, this accreditation involves two components: education and experience. If a structural engineer has completed the requisite educational qualifications and accrued sufficient relevant experience then they are deemed competent, and the resulting accreditation means that they can practise their profession in that jurisdiction. Regulatory oversight can then be ‘light touch’. For example, the Building (Scotland) Act 2003 offers the option that ‘experienced, competent and responsible professionals can certify compliance with the Building Regulations without any further check by local authorities, provided that they are employed by reputable companies operating proper checking procedures.’19

If fire safety engineers, like structural engineers, could be trusted to be competent and ethical, then regulators would not need the expertise to carry out detailed analysis of proposed fire safety solutions. Expertise asymmetry would not be such a concern so

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long as there was no expertise deficit within the fire safety profession, and engineers could be trusted to behave appropriately. Although engineers operating in a commercial context will always be subject to pressure to save money and time, as professionals they should be inculcated with norms geared towards acceptable levels of safety, with professional exclusion and, ultimately, criminal prosecution providing potential sanctions for deviant behavior (Spinardi 2016).

However, there are two inter-related objections to relying on self-regulation of the use of PBD for fire safety. The first concerns whether fire safety engineering can be considered a sufficiently mature profession for its members to be trusted to be both competent and ethical; the second centres on epistemological issues with regard to how we know about the fire safety of buildings. With regard to the behavior of fire safety engineers, the main concern is that in many jurisdictions (though not the USA) fire safety engineering is not a ‘protected profession’, and so professional qualifications and accreditation are not needed in order to practise as a fire safety engineer. Moreover, fire safety engineering is a relatively new discipline and its practitioners come from a wide range of backgrounds, with disparate levels of education and experience, and it is not clear that the accreditation provided by organisations such as the Institution of Fire Engineers (IFE) provides sufficient assurance of competence (see Spinardi 2016). While what is typically called ‘fire protection engineering’ is a protected profession in the USA, this ensures competence in the application of prescriptive fire safety techniques rather than in the expertise needed to carry out PBD. Serious incompetence and/or malpractice by a US professional engineer (PE) would result in the loss of their treasured and hard-won PE status, and so even though any financial liability would likely be covered by their employer’s insurance, the individual would suffer devastating reputational and career damage. Because fire safety engineering is not a protected profession in most other jurisdictions, the threat of losing accreditation carries less weight, particularly as the specific circumstances that could expose an inadequate fire safety design and lead to a major fire may never transpire.

The second issue with relying on self-regulation based on professional expertise stems from the difficulty of ‘knowing’ fire safety. Fire safety engineers might contest the claim made by May (2007, 21) that they have an ‘inability to assess or predict performance’, but such predictions certainly pose challenges. Fire safety engineering spans three diverse disciplines - all of which involve stochastic processes - and operates in a societal context that typically does not provide unambiguous guidance as to what ‘safety’ means (Meacham 2010). So long as occupants are able to behave in risky ways and to choose their buildings contents, it is

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not possible to make people absolutely safe from the risk of fire in buildings. Fire safety is thus a relative property, based on the likelihood that fires of certain types will occur in certain types of buildings, but with the solutions mandated by prescriptive rules having a good track record in reducing the risks. Engineering-based PBD solutions can be seen as what Petroski (1992) calls ‘engineering hypotheses’ with only a limited historical track record of performance, and with the ever-present possibility that inadequate understanding or mistaken assumptions will result in failures. Thus, the risk of failure is likely to increase the more that engineers believe (and are allowed to believe) that they so completely understand all the phenomena involved as to be able to shave margins of safety to a minimum.

Heavy reliance on judgment is inevitable, with the potential for unconscious bias in favour of cost-cutting approaches. Moreover, poor fire safety designs may lie dormant because serious fires typically only occur when there is a confluence of a particular combination of events. Substandard fire safety engineering may thus not be revealed for many years, the individual(s) responsible may escape the consequences, and feedback to the industry will be absent or delayed. In addition, because PBD by its very nature involves bespoke solutions for individual buildings, which vary greatly in their nature, experience may provide a poor guide to the future. Whereas, as Downer (2017) argues, aviation safety can be provided by self-regulation in part because innovation is incremental and risk-averse in nature, building carefully on the lessons of previous failures, PBD fire safety designs (and construction projects) vary greatly, and involve a large number and turnover of organisations and engineers with no coordinating mechanisms to share the lessons of failure or build institutional memory.

It is thus important that fire safety engineering learns not simply from its own failures, but also more generically from other engineering disciplines. The essence of engineering is to fine-tune to achieve efficiency (within the broader aims of the project), but it is crucial that engineers are reflexive in understanding the limitations of the knowledge on which they base their engineering judgments. As Sibly and Walker (1977, 206) conclude in their account of infamous bridge failures: ‘As time passed during the period of development, the bases of the design method were forgotten and so were their limits of validity. Following a period of successful construction a designer, perhaps a little complacent, simply extended the design method once too often’. Such reflexivity should be ingrained in the education of fire safety engineers because, as engineering historian R J M Sutherland argued in a discussion held by the British Institution of Structural Engineers, major engineering disasters ‘are much more likely to avoided if

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future designers, individually, develop a habit of looking back and questioning how each concept grew’ (quoted in Petroski 2012, 331). Alongside such individual responsibility, collective mechanisms would be desirable to give effect to the maxim of Confucius that: ‘Real knowledge is to know the extent of one’s ignorance’.20

The challenges to trusting fire safety professionals to self-regulate are not insurmountable so long as appropriate oversight mechanisms are enacted. Fire risks cannot be eliminated because of the epistemological difficulties with knowing fire safety, exacerbated by the lack of experience with PBD buildings, and the potential for user behaviour to subvert the effectiveness of the design. What Downer (2011) terms ‘epistemic accidents’ are thus inevitable, but good governance can minimise their frequency and impact. Without significant increases in funding the local government building authorities who regulate approval of fire safety designs cannot provide adequate scrutiny of the detailed rationale put forward because of the inevitable ‘expertise asymmetry’ between them and the fire safety engineers. However, they can insist on good working practices (such as providing clear statements of how the ‘level of safety’ of the planned building was determined, what the margins of safety are, and why the chosen range of modelling scenarios provide appropriate evidence).

More broadly, regulatory systems should also require that fire safety engineering is a ‘protected profession’ with an appropriate standard of qualifications and experience for the accredited members of that profession. The regulatory and legal system needs to provide an effective ‘backstop’ so that deviation from professional standards would incur penalties. Serious infringements should be publicised to prevent perpetrators from avoiding reputational damage by settling out of court.

Conclusions

Expertise asymmetry poses a challenge for the use of PBD in fire safety regulation because many building approval authorities lack the expertise to interrogate the knowledge claims made by fire safety engineers. PBD offers the potential for more rationally engineered fire safety solutions tailored to the needs of specific buildings, but its emergence as an aspect of neo-liberal deregulation raises concerns. In particular, the hollowing out of the capacity of the state to regulate exacerbates the problem of expertise asymmetry, while it is not clear that the professionalisation of fire safety engineering as a discipline has reached a sufficient state of maturity to compensate for the lack of adequate regulatory oversight.

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There has been little societal pressure to address this problem because in the jurisdictions surveyed here fire deaths have generally decreased in recent decades (markedly in England), and the majority of those deaths occur in domestic fires in buildings that are not typically regulated by PBD. However, fire statistics reflect many factors. For example, much of the reduction in deaths in England is most likely mainly due to increasing use of smoke alarms encouraged by more proactive fire services. Moreover, many PBD buildings are large occupancy and/or high-rise constructions with potentially high risk and it is clearly better to be safe rather than to be sorry in such instances. If there is evidence that PBD is not providing adequate regulatory oversight then action should be taken before rather than after a fire disaster.

The Grenfell Tower fire highlighted the danger of relying on historical statistics and simple prescription as a guide to the effectiveness of fire safety precautions. Earlier concerns about cladding fires were dismissed on this basis with, for example, Peter Field, Deputy Director of the Fire Research Station testifying in House of Commons hearings in 1999 that ‘the evidence so far would suggest the risk is not too significant compared with living one’s ordinary life’ (House of Commons 1999, 15). As it turned out, MP John Cummings was tragically prophetic when he asked: ‘Have we got to wait until there is a catastrophe of significant proportions before we express concern?’ (House of Commons 1999, 23).

This catastrophe arrived on 14 June 2017, but what is important now is that we focus on preventing the next disaster rather than just the last one. It is tempting to view all fire safety issues through the lens of Grenfell, but this would be to fall into the trap of the ‘stable door’ approach (fixing the problem after the horse has bolted). Full understanding of how the refurbishment of Grenfell Tower was designed, approved, and enacted must await the conclusions of the Public Inquiry and the criminal investigation, but it seems unlikely that it centred on the performance-based design issues discussed in this paper. Instead, Grenfell appears to have been possible due to a combination of regulatory complacency and incompetence, which proved deadly in the face of complex and ambiguous statutory guidance and regulations.

These specific issues were highlighted by the Independent Review of Building Regulations and Fire Safety, chaired by Dame Judith Hackitt, that was set up following Grenfell. The Interim report of the Hackitt review supports this paper’s concerns about expertise, noting that ‘systems for ensuring that individuals had the right level of expertise and were formally registered and accredited with professional bodies were seen as inadequate and as carrying serious risks in situations where inadvertent errors could have disastrous impact’ (Department for Communities and Local

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Government 2017, 86). In the case of Grenfell, the expertise failings appear to have centred on the application of prescriptive guidance rather than in the understanding of fundamental fire science. Addressing the confusing nature of prescriptive guidance, the Hackitt final report recommends simplification, but also strongly emphasises the need for an ‘outcomes-based’ approach to regulation (using the phrase almost fifty times) (Department for Communities and Local Government 2018).

However, Hackitt does not provide guidance as to how such outcomes should be defined or monitored. Because fire safety outcomes can only be measured after the fact, with aggregate statistics of fire losses and casualties, any reliance on outcomes-based regulation depends on addressing the expertise issues inherent in the use of PBD. Ironically, although the Government has indicated it will implement the Hackitt recommendations, its only regulatory change to date has been ‘stable door’ rather than ‘outcomes-based’ in nature. A ban on combustible materials in external walls above 18 metres is being implemented through an amendment to the Building Regulations21, thus bypassing the role of the functional requirements for fire safety. Doing so not only obviates the logic of an outcomes-based approach, but also undermines the argument for improved competency in the industry.

Grenfell thus confirms the concerns of this paper with regulatory and industry expertise, but the solutions outlined by Hackitt can only remedy the particular challenges posed by PBD if accompanied by substantive measures that tackle the expertise issue. The key lesson of Grenfell is that reliance on the aggregate statistics of fire casualties can lead to complacency with regard to the expertise needed to enact fire safety regulation. In the case of PBD regulation, this means we need to focus on ensuring adequate levels of expertise relevant to the understanding and application of fundamental fire science if we are to avoid a performance-based design fire disaster. Significantly more resources need to be invested in training local design approval authorities (perhaps with some concentration of effort) and/or non-prescriptive fire safety design should be restricted to engineers with appropriate qualifications, with clear professional and legal sanctions for malpractice.

Does this analysis of the expertise issues with performance-based design in fire safety regulation have implications for the oversight of other risky technologies? Buildings are distinctive in the degree to which both their design and their use are non-standardised, and so regulation of building fire safety has characteristics that are not directly relevant to many other technologies. Unlike many technologies (such as aircraft or drugs), it is not possible to seek to reduce risk by testing of prototypes before regulatory approval

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because buildings are typically bespoke in nature (indeed that is the essence of the PBD approach). Moreover, fire safety performance cannot, in general, be directly measured except retrospectively in terms of aggregate fire statistics. This means that the use of PBD in fire safety necessities a heavy reliance on knowledge claims about prospective performance that is not so important in technologies where a design can be tested in advance or where operational performance can be monitored.

The expertise issues discussed in this paper are thus most significant for technologies that are bespoke in nature and/or where safety critical aspects cannot be readily measured during operational use. The former is certainly the case (and the latter partially) with nuclear power reactors; Downer (2017) has made the important point that the bespoke nature of nuclear plants means that, compared with airliners, it is hard for the nuclear industry to learn from failure. However, even where technologies can be fully tested in advance, the design, conduct and interpretation of such tests requires expertise if ‘regulatory capture’ is to be avoided. The politics of populism and its denigration of experts is beyond the scope of this paper (see Nichols 2017), but left alone ‘the market’ can be a cruel master when it comes to learning about the risks presented by technology. If we are to continue a long tradition of regulating to reduce risk – in fire safety and elsewhere – then sufficient regulatory capacity independent of the regulated industry must be maintained so as to avoid ‘expertise asymmetry’.

References

Abraham, J. (1993) Scientific Standards and Institutional Interests: Carcinogenic Risk Assessment of Benoxaprofen in the UK and US. Social Studies of Science 23, 387-444.

Abraham, J. and J. Sheppard (1999) Complacent and Conflicting Scientific Expertise in British and American Drug Regulation: Clinical Risk Assessment of Trizolam. Social Studies of Science 26, 803-843.

Abraham, J. and C. Davis (2009) Drug Evaluation and the Permissive Principle: Continuities and Contradictions between Standards and Practices in Antidepressant Regulation. Social Studies of Science 39, 569-598.

Alvarez, A., B. J. Meacham, N. A. Dembsey and J. R. Thomas (2013) Twenty Years of Performance-based Fire Protection Design: Challenges Faced and a Look Ahead. Journal of Fire Protection Engineering 23, 249-276.

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Approved Document B, Published by NBS for Department of Communities and Local Government. Available at: https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/441669/BR_PDF_AD_B2_2013.pdf

Arnold, J. (2005) Large Building Fires and Subsequent Code Changes. Department of Development Services, Building Division, Las Vegas.

Babrauskas, V. and R. B. Williamson (1978a) The Historical Basis of Fire Resistance Testing – Part I. Fire Technology 14, 184-194.

Babrauskas, V. and R. B. Williamson (1978b) The Historical Basis of Fire Resistance Testing – Part II, Fire Technology 14, 304-316.

Bankoff, G., U. Lubken and J. Sand (eds) (2012) Flammable Cities: Urban Conflagration and the Making of the Modern World. University of Wisconsin Press.

Beck, V. (1997) Performance-based Fire Engineering Design and its Application in Australia. Invited Lecture, Fire Safety Science – Proceedings of the Fifth International Symposium, 23-40.

Brannigan, F. L. and G. P. Corbett( 2008) Brannigan’s Building Construction for the Fire Service. Fourth Edition, Jones and Bartlett Publishers, Sudbury, MA.

Brannigan, V. M. (1999) Fire Scenarios or Scenario Fires? Can Fire Safety Science Provide the Critical Inputs for Performance Based Fire Sadety Analyses? Fire Safety Science – Proceedings of the Sixth International Symposium, 207-218.

Braun, E. and D. Wield (1994) Regulation as a Means for the Social Control of Technology. Technology Analysis & Strategic Management 6, 259-273.

Buchanan, A. H., B. L. Deam, M. Fragiacomo, T. Gibson, and H. Morris (2006) Fifteen Years of Performance-Based Design in New Zealand. 9th World Conference on Timber Engineering, 6-10 August.

Buckett, N. (2014) A Code to Build By. Build (June/July), 49-50.

Bullock, M and A. Monaghan (2014) Code Compliance or Fire Engineering for Life Safety Design – have we moved on? International Fire Professional (April), 25-28.

31

31

Clayton, A, G. Spinardi and R. Williams (1999) Policies for Cleaner Technology: A New Agenda for Government and Industry. Earthscan.

Coglianese, C., J. Nash and T. Olmstead (2003) Performance-Based Regulation: Prospects and Limitations in Health, Safety, and Environmental Protection. Administrative Law Review 10(4), 705-729.

Coglianese, C. and D. Lazar (2003) Management-Based Regulation: Prescribing Private Management to Achieve Public Goals. Law & Society Review 37, 691-730.

Collingridge, D. (1980) The Social Control of Technology. Pinter, London.

Collins, H. M. (1985) Changing Order: Replication and Induction in Scientific Practice. Sage.

Dando-Collins, S. (2010) The Great Fire of Rome: The Fall of Emperor Nero and his City. Da Capo Press.

Davis, C. and J. Abraham (2013) Unhealthy Pharmaceutical Regulation: Innovation, Politics and Promissory Science. Palgrave Macmillan, Basingstoke.

Demortain, D. (2017) Expertise, Regulatory Science and the Evaluation of Technology and Risk: Introduction the Special Issue. Minerva 55, 139-159.

Department for Communities and Local Government (2017) Building a Safer Future: Independent Review of Fire Safety and Building Regulations: Interim Report. Cm 9551

Department for Communities and Local Government (2018) Building a Safer Future: Independent Review of Fire Safety and Building Regulations: Final Report. Cm 9607

Downer, J. (2007) When the Chick Hits the Fan: Representativeness and Reproducibility in Technological Tests. Social Studies of Science 37, 7-26.

Downer, J. (2010) Trust and Technology: The Social Foundations of Aviation Regulation. The British Journal of Sociology. 61, 83-106.

Downer, J. (2017) The Aviation Paradox: Why we can ‘Know’ Jetliners but not Reactors. Minerva, 55, 229-248.

32

32

Easton, B. (2010) Regulatory Lessons from the Leaky Home Experience. Policy Quarterly 6, 42-47.

Edwards, P. (2010) A Vast Machine: Computer Models, Climate Change, and the Politics of Global Warming. MIT Press.

Ekholm, M. (2015) Comparison of FDS simulations – user impact and quality assurance. https://lup.lub.lu.se/student-papers/search/publication/ 5365715

Epstein, S. (1996) Impure Science: AIDS, Activism, and the Politics of Knowledge. University of California Press, Berkeley.

Ferreira, M. J., E. R. Rosenbaum, M. S. Ballard and B. Schultheis (2002) UBC Section 905.0 – Smoke Control, A Case Study of the Implementation of Performance-Based Building Codes in the United States. 4th International Conference on Performance-Based Codes and Fire Safety Design Methods, 52-62.

Fleischmann, C. (2011) Is Prescription the Future of Performance-Based Design? Fire Safety Science – Proceedings of the Tenth International Symposium, 77-94.

Gobeau, N. and X. X. Zhou (2004) Evaluation of CFD to predict smoke movement in Complex Enclosed Spaces. Research Report 255, Health and Safety Executive.

Hall, J. R. and J. M. Watts (2008) Fire Risk Analysis. In The Fire Protection Handbook, Vol. 1 20th Edition Section 3, National Fire Protection Association, Quincy, MA..

House of Commons (1999) Potential Risk of Fire Spread in Buildings via External Cladding Systems, Environment, Transport and Regional Affairs Committee, HC-741-i.

HMSO (1981) The Future of Building Control in England and Wales. Cmnd 8179, London.

James, M. (n.d.) The New Zealand Building Code Verification Method VM2 –Four Years On – A Practitioners Perspective. https://www.originfire.co.nz/wp-content/uploads/2016/08/The-New-Zealand-Building-Code-Verification-Method-VM2-4-years-on-Michael-James1.pdf

Johansson, N. (2014) Numerical Experiments and Compartment Fires. Fire Science Reviews 3, 1-12.

33

33

Knowles, C. C. and P. H. Pitt (1972) The History of Building Regulation in London 1189-1972. Architectural Press.

Law, M. (1991) Fire Safety Design Practices in the United Kingdom – New Building Regulations. Conference on Fire Safety Design in the 21st Century, Worcester, Massachusetts, 8-10 May.

Law, M. and P. Beever (1995) Magic Numbers and Golden Rules. Fire Technology 31, 77-83.

Levy, C. and D. Martin (2015) Assessing Variability in Engineering Selection of Tenability Criteria, Presentation, SFPE conference, Copenhagen, June.

Ley, A. J. (2000) A History of Building Control in England & Wales 1840-1990. RICS Books, Coventry.

Levidow, L. (2001) Precautionary Uncertainty: Regulating GM Crops in Europe. Social Studies of Science 31, 842-74.

MacKenzie, D. (1989) From Kwajalein to Armageddon? Testing and the Social Construction of Missile Accuracy. In D. Gooding, T. J. Pinch & S. Schaffer (eds.), The Uses of Experiment, Cambridge University Press, Cambridge, 409-436.

MacKenzie, D. (1996) How Do We Know the Properties of Artefacts? Applying the Sociology of Knowledge to Technology. In R. Fox (ed.), Technological Change: Methods and Themes in the History of Technology Harwood, London, 247-263.

MacKenzie, D., & Spinardi, G. (1995) Tacit Knowledge, Weapons Design, and the Uninvention of Nuclear Weapons. American Journal of Sociology 101, 44-99.

May, P. J. (2003) Performance-Based Regulation and Regulatory Regimes: The Saga of Leaky Buildings. Law & Policy 25, 381-401.

May, P. J. (2007) Regulatory Regimes and Accountability. Regulation and Governance 1(1), 8-26.

Meacham, B. J. (2010) Risk-informed Performance Based Approach to Building Regulation. Journal of Risk Research 13(7), 877-893.

Ministry of Business, Innovation & Employment, New Zealand Government 2013 C/VM2 – Verification Method : Framework for Fire Safety Design. http://www.building.govt.nz/UserFiles/File/Publications/Building/Compliance-documents/c-vm2-protection-from-fire-amendment-3.pdf, accessed 17/9/2015

34

34

Mumford, P. J. (2010) Enhancing Performance-Based Regulation: Lessons from New Zealand’s Building Control System. Victoria University of Wellington Doctor of Philosophy thesis.

Nichols, T. (2017) The Death of Expertise. Oxford University Press.

Niles, M. C. (2002) On the Hijacking of Agencies (and airplanes): The Federal Aviation Administration, “Agency Capture,” and Airline Security. Journal of Gender, Social Policy & the Law 10, 381-442.

Perrow, C. 2015 Cracks in the “Regulatory State”, Social Currents, 2(3), 203-212.

Petroski, H. 1992 To Engineer is Human: The Role of Failure in Successful Design. Vintage Books.

Porter, S. (2009) The Great Fire of London. The History Press.

Ramsay, G. C. (1996) Fire Safety Engineering: Role in Performance-Based Codes, 3rd Asia-Oceania Symposium on Fire Science and Technology.

Rein, G., Torero, J. L., Jahn, W., Stern-Gottfried, J., Ryder, N. L., Desanghere, S., Lazaro, M., Mowrer, F., Coles, A., Joyeux, D., Alvear, D., Capote, J. A., Jowsey, A., Abecassis-Empis, C. and P. Reszka (2009) Round-robin study of a priori modelling predictions of the Dalmarnock Fire Test One. Fire Safety Journal 44, 590-602.

Ronchi, E. and D. Nilsson (2013) Fire Evacuation in High-Rise Buildings: A Review of Human Behaviour and Modelling Research. Fire Science Reviews, 2.

Sachs, E. O. (1903) Suggested Standards of Fire Resistance. In I. H. Woolson, Report of the Proceedings of the International Fire Protection Congress, 243-248, at 243.

Slayton, R. and A. Clark-Ginsberg (2017) Beyond regulatory capture: coproducing expertise for critical infrastructure protection. Regulation & Governance.

Sibly, P. G. and A. C. Walker (1977) Structural accidents and their causes. Proceedings of the Institution of Civil Engineers Part 1, 62, 191-208.

Spinardi, G. (2016) Fire Safety Regulation: Prescription, Performance, and Professionalism. Fire Safety Journal 80, 83-88.

35

35

Van der Heijden, J. (2010) One task, a few approaches, many impacts: Private-sector involvement in Canadian building code enforcement. Canadian Public Administration 53(3), 351-374.

Vaughan, D. (1996) The Challenger Launch Decision: Risky Technology, Culture, and Deviance at NASA. University of Chicago Press.

Wade, C., P. Beever, C. Fleischmann, J. Lester, D. Lloyd, A. Moule, N. Saunders and P. Thorby (2007) Developing Fire Performance Criteria for New Zealand’s Performance Based Building Code. Paper presented at the Fire Safety Engineering International Seminar, 26-27 April 2007, Paris.

Wolski, A., N. A. Dembsey and B. J. Meacham (2000) Accommodating Perceptions of Risk in Performance-Based Building Fire Safety Code Development. Fire Safety Journal 34, 297-309.

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36

1 For example, the definition of high-rise in San Francisco is 75 feet above street level, whereas in Las Vegas it is 55 feet. Interview A, San Francisco 16 April 2013.2 In addition to over 50 formal interviews, the author spent two weeks in the fire safety of a major engineering company in March 2014, and has had many informal interactions with fire safety engineers at conferences and seminars. Interviews were recorded and transcribed; note were taken during or shortly after other discussions.3 The five requirements in British building regulations cover these four main areas. See Schedule 1, Part B of Building and Buildings, England and Wales, The Building Regulations, 2010, pp 29-31.4 Interview B, Washington DC, 4 November 2014.5 Available at https://www.era.lib.ed.ac.uk/handle/1842/55746 In practice, this is not always simple because of the need to interpret the rules and their application. 7 Interview C, San Francisco, 18 April 2013.8 Interview A, San Francisco, 16 April 2013.9 Interview A.10 Interview D, San Francisco, 18 April 2013.11 Interview E, Edinburgh 26 October 2015.12 Interview C. emphasis added.13 Comment on earlier draft from a UK fire safety engineer.14 Although UK fire service advice comes with the proviso that their approval of a specific design should not be seen as setting a precedent for future cases.15 Presentation by Paula Beever, LRET Fire Safety Engineering seminar, Gullane, Scotland, 29 April 2013.16 Interview F, Genoa, 2 September 2015.17 http://www.gov.scot/Resource/0051/00517691.pdf18 D. Walker, ‘Certification of Building Design’, IABSE Symposium, Weimar, 19-21 September 2007. My thanks to the author for providing a copy of this paper.19 Scottish Buildings Standards Agency, A New Building Standards System for Scotland. https://www.ser-ltd.com/scotland/ClientGuide/ClientGuide.pdf20 My thanks to Angus Law for bringing this quote to my attention.21 http://www.legislation.gov.uk/uksi/2018/1230/regulation/2/made