THE GRENFELL inquiry will continue to hold hearings despite the national lockdown, it revealed, while expert witness Paul Hyett gave evidence on architects, fire consultants and cladding.

In an announcement, the inquiry hosted a statement from inquiry chair Sir Martin Moore-Bick, who said: ‘In the light of the Prime Minister’s announcement that the government intends to introduce a nationwide lockdown from this Thursday, I think it may be helpful to explain the Inquiry’s position. The Inquiry is a workplace which already has robust measures in place to enable us to conduct hearings safely and in accordance with government guidelines.

‘That means we can continue to sit during the period of renewed restrictions. Of course, depending on how things develop, there may come a point at which the position needs to be reconsidered, but for now, like the courts, we shall continue to function in accordance with the thorough risk assessment process undertaken by the Government Property Agency.

‘Protecting the health and safety of all continues to be a high priority for the Inquiry, so we may find it necessary to depart from our established procedures from time to time. In order to keep the number of people in the building to a minimum, we shall be asking those legal representatives who wish to make oral opening statements for Module 2 to do so by video-link.  

‘I am grateful to all those, particularly those behind the scenes, whose support makes it possible for us to continue hearings under difficult circumstances.’

Building and Inside Housing reported on the start of this week’s evidence from former president of the Royal Institute of British Architects (RIBA) Paul Hyett, an expert witness. He said that Grenfell architect Studio E was ‘imprudent’ not to have appointed a specialist fire consultant when taking on the project, and given lack of experience in overcladding high rise residential buildings ‘it would have been important for them to get a fire consultant and to use that fire consultant properly’.

Inquiry counsel asked him a series of questions about architects’ training in the Building Regulations and fire safety, as well as the level of competence ‘that could be reasonably be expected of them’, asking first whether Studio E should have refused the project having not had the relevant overcladding experience. Mr Hyett said: ‘We are designers and we are trained to design and, through design, to solve problems.

‘So the fact an architect hasn’t done, in this case, a building of the scale and type at Grenfell doesn’t suggest to me there’s an immediate problem. The important thing is to understand that code has to be researched, has to be understood, has to be applied and, where advice is needed from other specialists – either architects with particular experience in that area brought in to the office as subcontractors or … other consultants like a specialist fire consultant – architects have to know that they must, in researching the project, get the right experience into that project as it develops.’

Asked if the ‘standard of service expected’ could have been achieved via continual professional development or research alone, he said ‘yes […] I’m in no doubt that it could’; asked in turn if he’d expect it to have hired a specialist façade engineer or consultant, Mr Hyett said: ‘No. I would expect them to look very hard at the problem to satisfy themselves – or to question themselves whether they had resource in the office that could do the research necessary and develop the expertise necessary, or whether they should make a strategic hire.’

Mr Millett then asked how early in a project this should happen, Mr Hyett stating ‘at the beginning’, as the ‘foundations of the project would need to be right from the beginning’ and ‘time is ticking fast on a project once the instruction comes’. Studio E associate Neil Crawford had used facade engineer Arup for cladding on a Manchester office block for his previous practice, and asked whether Mr Crawford should have done the same for Grenfell, Mr Hyett said it was ‘perfectly reasonable to proceed without a specialist facade specialist on an overcladding project’.

Mr Hyett was then asked whether it was ‘unreasonable’ for Studio E not to have hired a fire consultant, to which he replied: ‘I don’t think they’re absolutes but the experience Studio E had would suggest this is a building type they have not done before. It’s certainly pretty substantial and complex. One would have to make an extremely good argument for not having a fire consultant.

‘That argument might be, “Well, we’ve been doing these for 15 years and we know all about it , we’ve got some highly specialised architects in the office who have done 10 of these before”. But looking at it from where they were coming from, I think that it would have been very, very prudent – it would have been important for them to get a fire consultant and to use that fire consultant properly.’

Pushed by Mr Millett, who asked if it was ‘therefore imprudent’ to have not hired one, Mr Hyett said: ‘That particular firm? Yes. I’m not saying that no architect could have proceeded without, but that particular firm, a partner in that firm – when we take on work, we’ve got to be confident that we can deliver what is required.

‘We have to look at our resources, we have to look at the skill, the size, and we have to satisfy ourselves we can do that work and do it with a competence and a confidence. I wouldn’t have wanted to proceed on that without getting a fire consultant. If you think you can address the problem as an architect, as a designer, then I think it’s reasonable to proceed.

‘But you would have to make the case for why you wouldn’t be going to a specialist. And I think from where they sat I would, as a partner, have said, “We need a fire consultant on this”.’

Later, he noted that official government guidance had permitted the use of cladding with a Class 0 rating on high rise building before Grenfell, Inside Housing noting that the Reynobond aluminium composite material (ACM) panels used had a certificate from the British Board of Agrement that said the panels ‘may be regarded’ as having the rating.

Mr Hyett said that ‘it is therefore my opinion that the guidance… endorsed, in principle at least, the use of the Reynobond aluminium composite panels for use on a project such as Grenfell Tower. It is my further opinion that most architects would have considered that such endorsement indicated that, in principle, the panels also met the requirements of the building regulations. That would certainly have been my conclusion’.

The news outlet said this was a conclusion the government ‘has vociferously resisted’ since the fire, including issuing a clarification eight days after insisting that composite panels were required to meet the higher standard of ‘limited combustibility’, and called the Grenfell cladding ‘banned’ because of a reference to ‘filler material’ in Approved Document B of the Building Regulations (ADB), which it claimed referred to the combustible polyethylene core of a cladding panel.

At the inquiry, Mr Hyett rejected this, stating: ‘I do not think that the authors of ADB intended the term ‘filler’ or ‘filler material’ to mean any part of a composite material (eg aluminium composite panel) that is factory manufactured and delivered to site as a finished product. Rather, it is something (either solid (eg polystyrene), granular (eg sand) or fluid (eg mastic)) that is put into, squeezed into or poured into a host environment.’

The news outlet added that this ‘hotly debated’ issue had seen industry figures accuse the government of ‘seeking to dodge liability’ by reinterpreting guidance, with ministers and officials warned in 1999 that Class 0 needed to be tightened, and several written warnings given post Lakanal, yet ‘no amendment was ever made to guidance’.

Mr Hyett had not been asked about this, but said that the use of combustible insulation behind the ACM was ‘clearly not permitted’ on high rises, and it should have been ‘rejected from the outset as an insulation material suitable for use’. Because of this and other errors, he added, there was a ‘widespread failure’ by Studio E to following guidance in ADB.

He also presented a 3D model to the inquiry of the cladding system as designed by Studio E, which ‘illustrated known flaws’ including cavity barriers placed at lines between flats instead of above windows; combustible insulation being used; and the ‘large gap’ created by moving new windows forward. He then demonstrated a way to build up the system with non combustible insulation and ‘correctly positioned barriers’, which would have ‘achieved a similar aesthetic appearance’.