Lecture by Professor José Torero, University College London
The British Section of the IESF organised this prestigious lecture and jointly hosted the event with the ICE Safety Risk Advisory Group. Professor Torero reminded a large audience of over 300 construction and fire engineers in the ICE Telford Lecture Theatre about the systemic failures that were the root cause of the Grenfell Tower fire disaster. The lecture was a very honest and forthright tour de force and a sobering reminder of what went wrong. It is hoped that the many important messages conveyed by Professor Torero during his presentation have been appropriately captured in this report.
Think beyond the role of the cladding!
When we see the images of the Grenfell Tower burning, understandably the first thing that comes to mind is the issue with the combustible cladding. Professor Torero emphasised that the cladding is one part of an incredibly complex problem that needs understanding. We should open our minds and think beyond the cladding as a culprit of this event. Not to do so would create a significant disservice to the victims by oversimplifying the problem, which is much more complex than the choice of building materials.
The objective of the Public Inquiry was to try to understand not only what happened but also why in an endeavour to ensure that such incidents are never repeated. However, since the Grenfell Tower incident, there have been similar disasters in Valencia and Hong Kong that claimed many lives. Clearly, the reality is that such events are still happening and are still threatening the lives of many people.
Stage I of the Public Inquiry was concerned with what happened and took one year to complete. The events were analysed, explained and fundamentally understood. Stage II of the Inquiry commenced in 2018 and attempted to explain why it happened and this proved to be a much more complex problem, taking six years to complete. Within this period Dame Judith Hackitt published her report on a review of the Building Regulations in which she described the construction industry as “a race to the bottom”. There was an across the board misuse of Building Regulations, but she was unable to explain why.
Circumstances of the fire
The fire started soon after midnight in the small kitchen of flat 16 on the fourth floor. Although the fire was a moderate size on a scale routinely tackled by the fire service, flames vented from the kitchen window and the fire found its way into the cavity of the new cladding that had been fitted to the external façade of the building, comprising polythene core aluminium composite panels and combustible insulation. The combustion properties of polyethylene, the core in the aluminium composite panels, have been known since the 1930s. Polyethylene is easy to ignite, it spreads flame easily, it has a high heat of combustion and as it burns it melts and sheds burning droplets that can spawn secondary fires. All the knowledge necessary to predict the way in which the fire spread both vertically and laterally at Grenfell through the agency of the polyethylene core of the aluminium composite panels existed. The fire fighters attended to fight a one compartment fire but were completely overwhelmed by the developing external fire.
How the fire safety design of the building was flawed
Professor Torero reminded us that the building should have been designed to adequately contain such a small fire. What followed was the failure of all fire safety provisions, including the fire service. Safety critical systems must always have redundancies and all of the knowledge necessary to define this existed. However, as soon as the fire breached the compartment there were no response mechanisms in place. Professor Torero posed the question – how could this be possible?
Small footprint, high-rise residential buildings, such as Grenfell, are among the simplest buildings to design from the fire safety perspective. A properly designed building with fire resisting compartmentation enables the fire service to rely on the “stay-put” strategy, which was a robust and commonly used approach to life safety that had a recognised track record. However, external fire spread, by definition, challenges that strategy. There have been many precedents of external fires with serious consequences and so by the time of the Grenfell Tower fire, we should have been prepared.
The engineering objective for the fire safety of the building was a one-unit fire, achieved by having a one-unit fire detection system, four levels of compartmentation redundancy, a safe route for egress and no external fire spread. Fundamentally, the fire service was not recognised as a redundancy to the building safety and instead they were thought of as coming to fight the fire and save the day, irrespective of the size and type of the fire. When confronted by the developing external fire they continued to try to fight it instead of moving into a rescue mission. The failure to achieve ‘no external fire spread’ in the fire safety objective led to a ‘single point failure mode’, bypassing all levels of redundancy. Furthermore, a conflict was introduced by giving the Fire Service priority over the stairs which became filled with smoke and the stay-put strategy could not be reversed. This placed enormous pressure on senior fire service personnel who were faced with making the unfair decision of taking occupants from a very risky environment in their own units to the equally risky environment of a staircase filled with smoke.
In what can be viewed as a classic example of the Swiss cheese model, Professor Torero summarised the position as follows. “Everything that happened was foreseeable, the knowledge to prevent the outcome existed and, for a building of that nature, all those involved in the design, construction and management of the building should have had that knowledge and ought to have exercised that knowledge in the design, construction and maintenance of the building”. So why was this knowledge not exercised?
The role of deregulation
In his review of important factors that contributed to the Grenfell Tower tragedy, Professor Torero started by examining the Building Act of 1984, which created a functional requirements system relying on performance-based design with guidance and which diminished the hierarchy of prescriptive solutions with rules used hitherto. The solution to the design of a safe building relied, therefore, on a combination of functional requirements and guidance without rules. It became necessary for the professionals to demonstrate that the design of a building meets the safety objective. The functional requirements system allows the professionals to define objectives that meet the tests of ‘appropriate’, ‘adequate’ and ‘sufficient’ and then do their analysis in an explicit way to demonstrate that their unique solution to their specific problem meets the requirements of the objectives.
For example, Requirement B4.(1) of Approved Document B to Building Regulations 2010 states “The external walls of the building shall adequately resist the spread of fire over the walls and from one building to another, having regard to the height, use and position of the building”. What does adequate mean in a building with a ‘stay-put’ fire safety strategy? Does it mean no fire spread – who decides?
The role of professionals and issues around competency
The functional requirements system fails to define professional boundaries. It is up to the professionals to define the objectives and the fire safety strategy, but Professor Torero questioned where does the fire engineer start and finish, when do the structural engineer and façade designer become involved and when does the architect become involved and take over the whole design? All professionals involved must understand each other and be able to speak the same language. Similarly, responsibility is also undefined because each project sets its own structure of responsibility and decides who does what.
The Building Regulations in terms of functional requirements place an enormous weight on professional competency. The recommendations of the Finniston report in 1979 to set up a new statutory Engineering Authority to protect the title and function of an engineer was opposed by the professional institutions to retain independence through self-regulation of membership, overseen by the Engineering Council. In the case of Grenfell there was an enormous presumption of competency, which was a product of a system that relies heavily on professional competency. The functional requirements framework evolved from the Building Act 1984 where functional requirements were supported by guidance set out in Approved Document B. The main inconsistency was the failure to establish a competency framework. There were no formal requirements about who could do fire safety engineering, there was no professional monopoly.
In the absence of a formal framework of competency, 30 years of deregulation by incompetence led to a systemic devaluing of knowledge and competency and over emphasis of nonprofessional relationships. An approvals system was constructed by means of which there was involuntary collusion between firefighters, authorities and engineers. Industry educated itself to take full advantage of the incompetence and poor regulatory framework. Professional organisations served as an enabler to perpetuate nonprofessional relationships. Competence became “the one who can get my building approved”. There had developed a widespread misconception that job title, in itself, denoted competency and Professor Torero expressed the view that this has not been sufficiently highlighted during University undergraduate teaching.
A fire event well understood left major questions on the competency of all those who played a part in the design, building and management of Grenfell Tower, including those who developed the legislation, performance tests and practice protocols, that allowed Grenfell to happen particularly on those who anointed those experts. The outcome was a total loss of trust in the fire engineering profession. Everyone is so incompetent that you can do what you want. This amounts to deregulation by incompetence.
Professions have attempted to define competency for centuries. You are not competent; you are deemed competent by those who participate in a subject. Professional competency must be regulated when the subject is one deemed complex and important to society. It is necessary to create a structure to regulate competency.
The way forward – the path towards recovery of trust
Professor Torero reminded us that much has been said about carrying out an appropriate fire risk assessment with proper objectives and an appropriate method. The government wants to use the PAS 9980:2026 to deliver an appropriate risk assessment, but this is very similar to PAS 79 that existed before and as a result it failed badly because it did not identify the most obvious of problems, the creation of a single point failure mode. For a stay put strategy, then “adequate” in requirement B4.(1) of Approved Document B to the Building Regulations dealing with external fire spread means “No”, and this should have been known. The fire detection system was not designed to inform the occupants of an alternative approach to fire safety and fire-fighting protocols, equipment and staff were defined for a one-unit fire.
For the first time we are facing the possibility of having an engineering discipline in the United Kingdom which is protected in name and function. The Government has acted and constituted a Fire Engineers Advisory Panel which issued an Authoritative Statement – “the establishment of fire engineering as a regulated profession, to be regulated in both title and function to restore trust”. This means that the activities of the fire engineer can only be performed by an individual who is registered and has met specific requirements. Fire engineers will hold formal responsibility for the development and stewardship of the fire safety strategy as a core function, with clear duties that are defined in regulation.
This augurs well for the future in which fire engineering is a regulated, accountable profession operating within a system that places the safety and wellbeing of all people at its core. In delivering the fire safety strategy, the role of the fire engineer is one of providing the link between multiple disciplines to ensure that design decisions come together to form a coherent and effective fire safety solution for a building and its occupants. The Government’s Policy Paper setting out the next steps on the reform of the fire engineering profession illustrates its commitment to implementing both the recommendations of the Grenfell Tower Inquiry Phase 2 report and the advice of the Fire Engineers Advisory Panel. This marks the beginning of a partnership between government, industry, regulators, and higher education to build a profession equipped for the future.
Chris Foster
Event details: The Grenfell Tower: Key Outcomes from the Inquiry and Further Change on the Horizon.