Design Doubt Duplicity

The profession of Fire Engineering has established BS 7974 Application of fire safety engineering principles to the design of buildings. Code of practice.

With a number of supporting BSI Public Documents that provide a systemised approach to Fire Engineering, BS 7974 has been the Code of Practice since 2001. BS 7974 was updated in 2019 following the fatal Grenfell Tower fire on 14 June 2017. Though, of course it is important to recognise that Grenfell Tower was not Fire Engineered to BS 7974. If that design and construction had been Fire Engineered to BS 7974 it might be hoped that there would not have been a breach of Requirement B4-(1) in Schedule 1 of the 2010 Building Regulations, and 72 deaths could have been avoided.

https://www.legislation.gov.uk/uksi/2010/2214/schedule/1/made

However, that hope has to be doubted.

Fire Engineering to BS 7974 exercised on Grenfell Tower could have identified some errors in design, and prevented their construction.

An obvious example is the contravention of Insulation Materials/Products Paragraph 12.7 as written in Approved Document Part B Volume 2 (2013) by procuring combustible Thermal Insulation in the external wall on a high-rise building defined with an upper Storey height over 18m above Ground Level. Paragraph 12.7 required “Limited Combustibility” for External Wall Insulation, defined in Table A7, Item 8.

Grenfell Tower Inquiry Judge Martin Moore-Bick questioned Expert Dr Barbara Lane, Leader of the Applied Innovation and Technology Group at Arup on the Insulation question:

[MM-B] "So the question is whether a reasonably competent fire engineer would, first , have noticed the proposed use of Celotex and, secondly, would have taken the trouble to find out what were the properties of Celotex."

[BL] "Yes. By 2013... there was sufficient concern in the profession about the description of insulation being, you know, categorised as class 0 rather than being required to be a material of limited combustibility. The minimum I’d expect is that written down, and if one had noticed Celotex in the stage C report, it would have been an extra step at that time to explore what that meant. Some professionals would have done it; some professionals would not."

Opus 2 International Grenfell Tower Inquiry Transcripts Day 61 - 28 October 2020, Page 193 Line 17 to Page 194 Line 6

https://assets.grenfelltowerinquiry.org.uk/documents/transcript/Transcript%2028%20October%202020.pdf

Another obvious example is the inadequate detailing and installation of Cavity Barriers in the ventilated cavity Rainscreen System, particularly around replacement Window Openings, where a gap had been created with the Fire Resisting solid concrete wall of the original building. Cavity Barriers with a Fire Resistance of 30 Minutes Integrity (E) and 15 Minutes Insulation (I) were and are required. Though there is an argument in my mind about whether the Rainscreen and Backing Wall that support them should have at least 30(E)15(I) Fire Resistance as the External Wall. That aside, Barbara Lane again:

[BL] "You’ve got professionals asking really specific questions about B4, as they’re entitled to do. They needed to hear that insulation, for a very long time, needs to be a material of limited combustibility , which is not class 0, and they needed to hear, regardless, cavity barriers were required around the window. And Harley [Facade Contractor] had shown them on the compartment lines, you know, where the walls and floors meet the cladding."

Opus 2 International Grenfell Tower Inquiry Transcripts Day 62 - 29 October 2020, Page 49 Line 12 to 19

https://assets.grenfelltowerinquiry.org.uk/documents/transcript/Transcript%2029%20October%202020.pdf

It is being argued out in the Grenfell Tower Inquiry whether avoiding these two errors in design and construction required the intervention of a Fire Engineer. They seem to be issues that should have been familiar to Architects and Contractors, although some of the Natural Persons giving testimony at the Inquiry seem studiously vague on these matters.

But would a Fire Engineer working to BS 7974 have better warned the Architects and Contractors that the Cladding chosen for the Rainscreen System on the Grenfell Tower was in breach of Requirement B4-(1) in Schedule 1. of the 2010 Building Regulations?

I don’t think so.

A Fire Engineer, had they been appointed to undertake a BS 7974 Fire Engineering service after 2001, would have needed competence. That has been suggested by Barbara Lane in the Grenfell Tower Inquiry as a CEng qualification. A Chartered Engineer assessed by one of the Institutions recognised by the Engineering Council established in 1987. That means a CEng member of the Institution of Fire Engineers, in the absence of any other Fire Engineering professional body being recognised by the Engineering Council in 2020.

Hold that thought…

Barbara Lane again:

[BL] "The three together are required to provide the performance... The cavity barriers were not there , the insulation was not compliant, and the external surface was highly combustible, and there’s nothing else to say, in my mind."

Opus 2 International Grenfell Tower Inquiry Transcripts Day 62 - 29 October 2020, Page 69 Line 5 to 13

https://assets.grenfelltowerinquiry.org.uk/documents/transcript/Transcript%2029%20October%202020.pdf

There is something else to say about the combustible external surface of Cladding...

There are three key components in the cavity construction of a Rainscreen System:

1. Insulation - Which at Grenfell failed to comply with Paragraph 12.7 as written
2. Cavity Barriers - Which at Grenfell were absent, badly installed, or bypassed in fire
3. Cladding - Which at Grenfell was "judged" Class 0 to BBA Certificate 08/4510

https://assets.grenfelltowerinquiry.org.uk/ARC00000678_BBA%20Certificate%20%2008_4510%2C%20for%20Reynobond%20Architecture%20Wall%20Cladding%20Panels.pdf

Barbara Lane had something to say about the Cladding at Grenfell Tower refurbishment in Clause 11.8.17 of Section 11 of her Phase 1 Report, referring to Clause 13, which I still think of as Paragraph 13 of Appendix A in Approved Document Part B Volume 2 (2013):

'The statement on the front page of the 2008 issue of BBA Agrement Certificate 08/4510 that "the panels are judged to meet the Class 0 requirements" is incorrect as two of the three panels specifically referenced in that certificate do not achieve Class 0 by any of the three means defined in Clause 13 of Appendix A of ADB.'

https://assets.grenfelltowerinquiry.org.uk/documents/Dr%20Barbara%20Lane%20report%20-%20section%2011%20%28Phase%201%20-%20supplemental%29.pdf

The something else to say is that Class 0 Cladding, even when tested rather than "judged" before being given a BBA Certificate, is potentially combustible in Paragraph 13b. The combustible types of Class 0 Cladding will allow the fire to bypass Cavity Barriers, and will involve any combustible Insulation. Paragraph 13 being the Ministry's approved definition.

Paragraph 13b. is NOT Limited Combustibility, and is NOT necessarily even combustible Class B-s3,d2 to BS EN 13501-1 Fire classification of construction products and building elements. Classification using data from reaction to fire tests.

That needs saying to make sense of Grenfell, and for that matter the ubiquity of Class 0 Cladding of 13a. and 13b. kinds across the country. Those kinds of Class 0 Cladding now need to be separately distinguished, neither being the same as the Class A2-s1,d0 limitation in Regulation 7(2) heralded as a "Ban" in Building (Amendment) Regulations 2018. Though the “Ban” was far from universal, and was only limited to the External Wall. Internal Cavity Walls and Internal Cavity Floors are not addressed by Regulation 7 except generally in Regulation 7(1). But cavities are recognised in Requirement B3-(4).

That will come to the fore as construction innovation continues to introduce cavities.

https://www.legislation.gov.uk/uksi/2018/1230/made

Hopefully Barbara Lane will say that Class 0 was NOT necessarily Limited Combustibility repeatedly and loudly as the Inquiry continues. Sure there are mitigating factors that conspired to make this fire complex to explain. But Cladding fuelled and spread the fire.

For the avoidance of doubt, the single, simple reason for the fire severity is that Paragraph 13b. Class 0 Cladding was approved by the Ministry for Architects to specify and Contractors to procure. Which they did, looking for Third Party Certification.

It is doubtful a CEng Fire Engineer would have prevented the use of Class 0 or even Class B-s3,d2 Cladding in the refurbishment of Grenfell Tower, that led to the severity of the fire spreading across the External Wall in rapid “roll-over”, defeating compartments.

The reason is Diagram 40.

Most Architects and Contractors would have read Diagram 40 in Approved Document Part B Volume 2 (2013) for the Surface of the External Wall when procuring Cladding. The most onerous Reaction to Fire classification in Diagram 40 is Class 0 (National) or Class B-s3,d2 (European). More combustible Cladding was approved on the less onerous cases of building height, use and proximity to the Boundary. So the market for Cladding was pitched for the most onerous cases of building at Class 0 or Class B-s3,d2.

These requirements were considered alternatives, not equals. Though Diagram 40 did appear to present an equivalence there was a caution in Diagram 40.

'The national classifications do not automatically equate with the equivalent European classifications, therefore, products cannot typically assume a European class unless they have been tested accordingly.'

The phrase “equivalent European classifications” throws the reader. But that caution did not stop the alternative of Class 0 or Class B-s3,d2 in Diagram 40. The Architect and Contractors, or for that matter any experienced Project Manager, would have read Diagram 40 as a choice with an upper limit. They could even have recognised that neither Class 0 or Class B-s3,d2 would mean “Limited Combustibility”. They could know that Diagram 40 in ADBv2 (2013) was approving combustible Cladding.

It would be reasonable for non-specialist Consultants and Contractors to expect that Diagram 40 had been considered by the Ministry to ensure compliance with Requirement B4-(1) of Schedule 1. of the 2010 Building Regulations, as cited in Section 12. The Approved Document was published under Section 6 of the 1984 Building Act, and Diagram 36 in 1991 before Diagram 40 in 2000 had approved Class 0 even before there was the European Classification alternative in BS EN 13501-1.

A smart Fire Engineer who was not yet CEng qualified might, like non-specialist Consultants and Contractors, have no doubt that Class 0 meant compliance with Requirement B4-(1) because of Diagram 40, and the limitation of Paragraph 12.7 to Insulation. Even if they were doubting the wisdom of that Ministry decision in everyday practice. A Fire Engineer who was not yet CEng qualified might have more insight and doubt more, but doubt would be quashed by belief if not in the veracity of the Approved Document, but in the authenticity of the approval.

Diagram 40 was authored by the Ministry. Class 0 was only defined by the Ministry in Paragraph 13 of Appendix A in ADBv2 (2013). Class 0 was approved for Cladding, and Insulation facing a cavity also needed to be Class 0, but “Limited Combustibility” in Paragraph 12.7 was a more onerous requirement for Insulation, and Cavity Barriers needed to be additionally Fire Resisting, as might some of the External Wall where it could not all be considered “Unprotected Area”.

But would a CEng qualified Fire Engineer doubt that the Ministry had got Class 0 Cladding wrong?

Nowhere have I yet seen the Institution of Fire Engineers test a Fire Engineer applying for a CEng on the Class 0 question. Maybe the IFE were saying that Class 0 was not “Limited Combustibility”. But I have seen nothing yet that would suggest the IFE was "Raising the Bar" on the combustibility of the External Wall BEFORE Grenfell Tower fire. It may yet be shown that combustible Class 0 was an IFE concern.

A CEng qualified Fire Engineer, may have doubted combustible Class 0 themselves, even without the IFE’s support. For that matter so might non-specialist Consultants and Contractors. But to insist on “Limited Combustibility” Cladding would require an effort above the Approved Document.

Without a BS 7974 Fire Engineering approach Consultants and Contractors, including a non-CEng Fire Engineer, might have noticed the inclusion of “Cladding Material” in BS 9991:2015 Fire safety in the design, management and use of residential buildings. Code of practice:

18.2 External fire spread over the external faces of buildings

‘b) In a building with a storey 18 m or more above ground level, any cladding material, insulation product, filler material (not including gaskets, sealants and similar), etc., used in the external wall construction should be of limited combustibility.’

Again, to insist on the BS 9991 18.2.b requirement for “Limited Combustibility” Cladding after 2015 would require an effort above the Approved Document.

Though the text of BS 9991 18.2.b had introduced a requirement for “Limited Combustibility” Cladding, Figure 17 that accompanied it was identical in meaning to Diagram 40, and unchanged by the 2015 BSI update. Cladding was Class 0 or Class B-s3,d2 in Figure 17, contradicting BS 9991 18.2.b in 2015.

Why did the BSI did NOT update Figure 17 to align with the 18.2.b requirement?

The Inquiry will hopefully get to that. The persistence of Class 0 for the External Surfaces of Walls can be traced back to 1991 and Diagram 36 in the Approved Document.

Without a BS 7974 Fire Engineering approach Consultants and Contractors, including a non-CEng Fire Engineer, might have known about the Building Control Alliance Technical Guidance Note 18, which in 2014 had said something similar to BS 9991 18.2.b in 2015. A Building Control specialist might have pointed that out. But to insist on “Limited Combustibility” Cladding after BCA TGN 18 of 2014 would require an effort above the Approved Document.

But would an alert CEng qualified Fire Engineer doubt that the Ministry had got Class 0 Cladding wrong?

Possibly. But would they be able to insist on “Limited Combustibility” Cladding and persuade Clients to tell their Consultants and Contractors that an effort above the Approved Document was the project instruction? Possibly not.

Should the frustrated and doubting CEng member of the IFE have resigned, or refused to sign the BS 7974 Fire Engineering Reports being expected by Building Control?

That would be brave in 2014 or 2015, but Grenfell Tower was designed in 2013.

Barbara Lane has not explored this yet in Phase 2. The CEng member of the IFE would have looked for Class 0 in 2013. They would have worked to BS 9991:2011 Fire safety in the design, management and use of residential buildings. Code of practice:

29.2 External fire spread over the external faces of buildings

'b) In a building with a storey 18 m or more above ground level, any insulation product, filler material (not including gaskets, sealants and similar), etc., used in the external wall construction should be of limited combustibility.' 

No mention of “Cladding Material” in BS 9991 29.2.b in 2011. But by 2016, when the refurbishment of Grenfell Tower was complete, BS 9991 had been altered mid-project. It might be asked whether a competent Fire Engineer would have written to the Client to warn them that the basis upon which they had refurbished was now in breach of BS 9991, though not in breach of the unchanged Approved Document.

But in the actual case of Grenfell Tower it remains a hypothetical question. That line of questioning is exhausting. The fact is there was no instruction for BS 7974 Fire Engineering by a CEng member of the IFE on Grenfell Tower refurbishment. Ever. If there had been it is probable that combustible Class 0 Cladding would still have been designed and constructed even if the errors in Insulation and Cavity Barriers had been caught. BS 9991 18.2.b in 2015 was negated by the continued Ministry approval of combustible Class 0 Cladding.

There is much hypothesizing going on in the Fire Engineering profession. It will emerge stronger as a profession as a result. Perhaps less certain is the future of the wider constituency of Clients, Consultants and Contractors in the construction industry. It may even depend on what Customers do next, perhaps doubting the RICS EWS1 Form.

https://www.rics.org/globalassets/rics-website/ews1-external-wall-fire-review-final-2.pdf

The duplicity of the Ministry in the EWS1 scandal threatens to discredit the state, and will not prevent the relentless realization of the Truth about Class 0 in the Grenfell Tower Inquiry, as painfully necessary as that is.

But doubt is also being elevated as philosophy in design and construction.

While Eoin Leonard, Chief Executive Officer at i3PT Certification agrees that Class 0 was not Limited Combustibility in Paragraph 13b. of Appendix A of ADBv2 (2013), he questions whether simply making External Walls less combustible is enough to ensure Fire Safety. That is an excellent question, but to what end?

It is true, of course, that the Building (Amendment) Regulations 2018 requires “Relevant Buildings” under Regulation 7(4) to have External Walls to Class A2-s1,d0 or Class A1 to BS EN 13501-1 as Regulation 7(2), subject to exclusions in Regulation 7(3). That exceeds the Class A2-s3,d2 threshold for “Limited Combustibility” in ADBv2 (2013), no longer referred to by that name in ADB (2019) in either Volumes 1 or 2.

Grasping that Regulatory precision might seem complicated, but it is not really when we try, as we must working in projects as professional Clients, Consultants and Contractors.

It is true, of course, that Clients instructing complex buildings with larger budgets require CEng members of the IFE to undertake BS 7974 Fire Engineering. The Approved Documents exist for those more numerous less complex and lower budget projects that do not require a CEng Fire Engineer.

However, Eoin Leonard has a more profound concern about Complexity, and I hope I do not misrepresent what he is saying. He suggests that Building Design is a "Wicked Problem" that has a complexity which is not resolved by addressing one variable, like the Reaction to Fire of the External Wall. The idea of a “Wicked Problem” derived from Dilemmas in a General Theory of Planning by Horst Rittel and Melvin Webber in 1973, in which they argued that "Planning problems are Wicked Problems". Available here:

https://link.springer.com/article/10.1007/BF01405730

By seeing a "Wicked Problem" Eoin Leonard is not saying that something as simple as extending the Regulation 7 “Ban” to lower heights, wider uses, or with more precise exclusions will be sufficient. He is not saying something as simple as extending the Regulation 7 “Ban” to the Internal Wall, that might be cavity construction, is enough. Or in a Modular stack to the Internal Floor that is a cavity construction connected to the extensive Internal Wall cavities. He might not have technical objections to any such thing, but they are isolated technical interventions.

Eoin Leonard is saying more philosophically that it is a myth for a Technical Designer like me to think that doing these things in isolation can solve the “Wicked Problem”.

This is philosophically related to but critical of the technically appealing call for “Systems Thinking”, or the perhaps more fashionable but vague demand for an “Wholistic” approach in building design and construction. But Rittel and Webber, and their successors, argue that such attempts are almost doomed to failure because the “Wicked Problem” is beyond professionals to resolve. If I think there is an "Anticipatory Design Science" I am professionally deluded, say Rittel and Webber, and their successors.

The “Wicked Problem” is a resignation in my view, but I’m of a Technical bent.

There was so much to consider in the Grenfell Tower refurbishment and subsequent fire that it is a mind-bending task to determine what happened, and then dissect and diagnose what went wrong in pursuit of those who failed in their professional responsibilities to ensure Fire Safety. Including not appointing a CEng Fire Engineer.

I don’t want philosophy to lose sight of the fact that the Approved Document in Paragraph 12.7 as it was written, not as the Government falsely said it should have been written after 14 June 2017, would have frustrated even the most alert and bravest CEng Fire Engineer, had they been appointed to BS 7974. Which no-one was.

A discussion about the philosophical “Wicked Problem” shows a healthy doubt. The measure of guilt being beyond reasonable doubt.

But it would be duplicitous for the Government to say Fire Safety was all too complicated, and that we wouldn’t have understood, if they had regulated against combustible Class 0 any time after 1999, when they were formally warned by their own Select Committee. A warning I believe repeated in the as yet unpublished RADAR Reports of 2002.

I am saying Fire Safety is not the “Wicked Problem” some would like it to be. Indeed, I don’t think there are problems in professional life that are so “Wicked” they can’t be addressed. I hope Eoin Leonard and others will argue this out.

Construction is not Rocket Science, and neither does a 1973 sociological theory have too much purchase on the task of establishing Fire Safe building design and construction.

Combustible Class 0 was part of systematic Fire Safety Engineering, and the norm for Fa?ade Engineers for that matter, until 14 June 2017.