By: Neal Butterworth, Director 

Two weeks ago, we attended our annual continuing professional development (CPD) event at the University of Edinburgh. As always, it was immensely educational, insightful and enjoyable.

This year’s theme was very loosely based on the concept of “regulation by disaster”. The concept combined a fantastic mix of politics, incentives and theory of legislation by disaster, in-depth explanations of a selection of case studies, and, of course, some lively lab sessions where we set fire to things!

The two-day event culminated with a presentation by Dr Angus Law, Senior Lecturer in Fire Safety Engineering at the University of Edinburgh. Dr Law addressed the imbalance between those in power and the victims of fire, using stark examples such as the Shirtwaist fire in New York City[1][ref], fires and structural collapses in factories in Bangladesh[2][ref] and the Bhopal gas leak tragedy[3][ref]. In each case, he very eloquently and soberingly reminded us that it is generally those with the power who impose the risk onto others.

This principle resonated strongly with me as someone who has been working almost entirely on cladding issues since the Grenfell tragedy in 2017. In particular, as I discuss in more detail later:

• The Government has transferred power to Fire Risk Assessment (FRA)[4][ref] and Fire Risk Appraisal of External Walls (FRAEW)[5][ref] risk assessors. These assessors are required to decide who must tolerate heightened risk and how much must be spent to reduce that risk.
• In the seven years since Grenfell, there has been no consensus on the level of risk that can be tolerated and almost nothing has been done to help and assist the risk assessors in quantifying risk.
• Risk assessors have the power and responsibility to balance safety risk against financial risk. Whilst leaseholders might not have to pay for risk reduction, they have almost no choice but to accept the decisions made by the risk assessor.
• There are no right or wrong answers; instead, our goal must be to find the best compromise between conservatism and proportionality and we must continuously strive to narrow the gap between the two.

Power to the people? It certainly is not. The residents have little choice but to accept the opinion of the risk assessor, who equally has no benchmarks of acceptability and no credible means or data to quantify risk – neither for decision making nor to explain to residents.

In the immediate aftermath of Grenfell, the Government stepped in. They produced a series of advice notes that advised building owners to remove all Grenfell-like cladding from buildings and to generally assume that the external walls of buildings are not safe until proven otherwise. In an attempt to spare leaseholders from footing the bill for buildings to be repaired, the Government created the Building Safety Fund (BSF) to provide financial support. At this point in time, the rhetoric was that building owners must ensure that their buildings are at least as safe as when they were first built, and if not, the Government would pay for them to be fixed.

However, as time passed, the Government realised that there were many more buildings that needed fixing than they initially anticipated, leading the BSF to run out of funds. Consequently, the Government decided that it would not be necessary to make all buildings as safe as they should have been, but instead, to accept that some level of heightened risk could and should be tolerated by residents; and instead of ‘a total remediation’ strategy, building owners should implement ‘risk-proportionate’ remediation.

Risk-proportionate remediation is a very practical and sensible approach, and one that I fully support. I am aware of many cases where vast amounts of money have been spent addressing supposed ‘defects’, often where the risk associated with the defect was negligible to the extent that the building has been totally re-clad without any tangible improvement to resident safety.

However, who decides?

Well, the Government has emphatically answered that question by changing the law[6][ref] to make FRA risk assessors decide what constitutes a tolerable level of risk. This has been backed up by the Cladding Safety Scheme and further legislation, which places risk assessment (and therefore risk assessors) at the heart of deciding how much risk must be tolerated, how much the taxpayer must pay to reduce risk and the contribution that must be made by the original developers.

Another key decision in risk-proportionate remediation is: how safe is safe enough?

This is a very difficult question to answer in an environment that has been built on compliance with approved guidance. For many years, Approved Document B has given us guidance / rules on how external walls should be constructed. This rules-based approach is not necessarily bad and certainly has merits, but one thing it does not do or even try to do is provide guidance on acceptable levels of risk or how to evaluate risk.

Similarly, there were risk-based guidance documents, but none of these included external walls within their scope.

In an attempt to help plug the hole, the Government sponsored a new British Standard (PAS 9980)[7][ref] that defines a risk-based methodology. Again, this was a very sensible and necessary thing to do (I would say that – I was a co-author). However, there are two fundamental problems that PAS 9980 cannot and does not solve:

• The benchmark of safety: how much increased risk is still safe enough to be tolerated?
• Risk evaluation: how much does any particular ‘defect’ increase risk?

So whilst PAS 9980 provides some useful methodology and a lot of useful information, the above two problems rely heavily on the competence and judgements of the risk assessor.

The now all-powerful risk assessor has some new clothes in PAS 9980, but they are still very much naked in the absence of any consensus benchmark of tolerable risk and in the absence of any knowledge, assessment methods or data to help them quantify the heightened risk associated with defects in design or construction of external wall systems. There is a growing body of BS 8414 test data that can be very useful, but there is limited (if any) data for systems that have defects similar to those that are frequently found in existing buildings.

In the world of existing buildings with existing defects this creates an impossibly difficult balancing act for the risk assessor. Normally, for a new building, designers use conservatism to mitigate uncertainty and can err on the side of caution. There is a similar, and very understandable, temptation for FRAEWs – it always feels appropriate to ensure conservatism and err on the side of over-estimating risk. However, an overly conservative FRAEW can and probably will result in unnecessarily onerous remediation. As such, the risk assessor has a very real and very difficult obligation to balance safety risk with cost risk. In many cases, the risk assessor has to decide whether residents can and must tolerate a heightened risk or whether and how much leaseholders must pay to reduce risk.

Faced with this difficult decision, there is clearly no right answer – or at least no right answer for everyone. As risk assessors, all we can do is use the knowledge and tools available to us to our best to arrive at the best compromise between conservatism and proportionality. That is to say to do our best to evaluate risk, do our best to judge when risk reduction is required, and do our best to consider a range of risk reduction measures and help the various stakeholders choose the option that give the greatest reduction in risk at the least cost.

We must also not stop there. There are still many buildings that need assessment and many building that are likely to need remediation, and so we must keep improving. This includes improving the knowledge, skill and experience of risk assessors as well as improving guidance and generating information and data that can be used by risk assessors. In this way, we can reduce the necessity to rely on conservatism (by being able to more accurately and certainly evaluate risk) and close the gap between conservatism and cost of risk reduction.

Both of the above have been recognised by the Grenfell Tower Enquiry. In the midst of many other recommendations, the two global technical regulations recommendations that are worth a mention here are (please forgive the paraphrasing):

1. Fire engineers should be registered by law[8][ref]and all higher-risk buildings should require the appointment of a fire engineer[9][ref].
2. More research and data should be made publicly[10][ref] available to enable fire engineers to do their engineering.

There will be great debate about the necessity and merits of the former. Of course it might (at least in the short term) make an already small pool of active FRAEW risk assessors even smaller, but in my opinion regulating the fire engineer profession will help to ensure, improve and police professional competence, which is surely only a good thing.

However, surely there can be no debate about the later. In the world of external wall constructions there is some, but very little, research and data on risk of fire spread, and negligible research and data on how defects in external wall construction might impact risk. This research and data is essential for risk assessors to accurately evaluate risk in existing buildings and for them to determine the most proportionate risk reduction measures.

At DFC we have started to play our part in this and will continue to do so. We have recently sponsored a research and testing program at the University of Edinburgh which we hope will provide data and information on the relative fire performance of different combinations of cladding and insulation. If successful the data will help risk assessors benchmark with more quantification and certainty the hazards and risks of different facade systems. We have also committed to make the data publicly available, so watch this space.

Conclusion

So Dr Law’s lecture was a very poignant reminder for me of the power that has been bestowed upon me and the associated burden and responsibility of having to balance safety risk against financial risk.

In many ways, it is a power that I would rather not have, but none-the-less someone has to help and someone has to be prepared to make or inform these decisions. As such, I will continue to do FRAEWs and as I do, I will do it with Angus’ sobering reminder of the great responsibility that results from the power that I have to impose risk on others. I hope all FRAEW assessors can do the same.

As for DFC, we recognise the need for more training, research and data and will be doing our bit to ensure the knowledge, skill and experience of our staff, contribute to industry improvement and help to increase the body of research and data within the public domain. We hope that the research at the University of Edinburgh is successful and useful to the FRAEW assessor community, and we very much look forward to publishing the data.

References:

[1] “Triangle Shirtwaist Factory Fire”: History.com, Editors, Original: December 9,2009, Updated: July 9, 2024.

[2] “Fires and structural collapses in factories in Bangladesh”: BBC News, Asia, May 10, 2013.

[3] “The Bhopal disaster and its aftermath: a review”: National Library of Medicine National Center for Biotechnology Information, Enviro Health. 2005; 4: 6, PMCID: PMC1142333. Published online 2005 May 10. doi: 10.1186/1476-069X-4-6, Author: Broughton, Edward, May 10, 2005.

[4] “The Regulatory Reform (Fire Safety) Order 2005”: The suitable and sufficient assessment of risk required by the Regulatory Reform (Fire Safety) Order 2005, LEGISLATION.GOV.UK.

[5] “Fire risk appraisal of external walls and cladding of flats – PAS 9980”: The British Standard Institution 2004, BSIGROUP.COM.

[6] “The Fire Safety Act 2021“: LEGISLATION.GOV.UK 2024.

[7] “Introducing PAS 9980:2022”: GOV.UK. 2024.

[8] “GTI Phase 2_Report Overview”: CCS0923434692-004_GTI Phase 2_Report Overview_E-Laying_0, paragraph 113.25, page 37.

[9] “GTI Phase 2_Report Overview”: CCS0923434692-004_GTI Phase 2_Report Overview_E-Laying_0, paragraph 113.15, page 35.

[10] “GTI Phase 2_Report Overview”: CCS0923434692-004_GTI Phase 2_Report Overview_E-Laying_0, paragraph 113.39, page 39.