Grenfell Inquiry: Officials Disagreed on Materials


In the most recent updates of the Grenfell Tower inquiry, it has come to light that there were disagreements between not only architects and building safety officers, but also between architects and engineers.

Separate officials with Studio E Architects spoke to the inquiry this week about the different disagreements on the envelope’s cavities, as well as the type of insulation used in the project.

Disaster Background

On June 14, 2017, Grenfell Tower—a 24-story, 120-home apartment building—caught fire and resulted in the death of 72 people. While the fire started in a fridge-freezer in an apartment on the fourth floor, the blaze then spread to a nearby window. The building had recently undergone a $12.73 million renovation designed by Studio E Architects that was completed in the spring of 2016 and is largely believed to be responsible for why the fire spread so quickly.

At that time, the building was refurbished with a system of polyester powder-coated aluminum rain-screen panels, insulated exterior cladding and double-glazed windows, as well as a communal heating system.

A Guardian investigation in 2018 revealed that nonflammable aluminum panels had initially been proposed for the refurb but were switched out to save money.

The publication found that, at first, under the local government’s preferred contractor, Leadbitter, subcontractor D+B Facades had provided a 3.3 million-pound (roughly $4.1 million) quote to fit a system of aluminum panels backed with mineral wool insulation.

A few months later, the council decided that Leadbitter wanted to spend too much on the refurbishment, and put the contract out to tender to save about 1.3 million pounds. It went with a different contractor, Rydon, which provided a lower bid, but fitted the tower with the combustible cladding that authorities believe contributed to the number of fatalities in the fire.

The Guardian found that the council had originally wanted to spend 6 million pounds on Grenfell, but later set a different budget of 9.7 million pounds, because it realized it needed to replace the heating system. Leadbitter was on course to spend 11.3 million pounds, which is why council says it put the contract back out.

Manufacturer Omnis Exteriors confirmed that they supplied the Arconic Architectural Product to Harley Facades—the subcontractor that Rydon utilized for the cladding work.

Around the same time in 2018, BBC News uncovered that the Reynobond PE cladding was subjected to European tests in 2014 and 2015 for “reaction to fire,” in which products are typically given an A to F rating, with A being the highest.

(Many officials believed that the legal standard for such towers was a B rating. While that belief had been contested among industry professionals, the legal minimum rating now, post-Grenfell fire, has been upgraded to A.)

The reports from the 2014-15 tests reveal that two types of the Reynobond, both of which were installed at Grenfell, had less than B ratings. One type, called “riveted,” received a C classification, while another, “cassette,” received an E classification.

The BBC obtained correspondence from Arconic to clients confirming the ratings.

The Inquiry

Phase One of the inquiry was completed last fall, with the findings published on Oct. 30. This phase was to look at what happened on the night of the fire itself, and the 1,000-page report criticized not only the response to the fire but the 2016 renovation as well.

Arguably of most importance, inquiry head Sir Martin Moore-Bick, a retired Court of Appeals judge, said that it seems that the refurbishment did not comply with the building regulations requirement to adequately resist the spread of fire.

“There is compelling evidence that Requirement B4(1) was not met in this case,” he said. “It would be an affront to common sense to hold otherwise.”

In addition to the preliminary conclusions on the 2016 refurbishment, the report also accuses the fire brigade’s response to the fire as having “systematic failures” with no contingency plan to evacuate the tower. It also criticized the brigade’s decision to maintain the “stay-put policy” even when the stairs were passable.

After the report, Dany Cotton, the London Fire Commissioner who was in charge of the response, resigned.

The second phase, which started Jan. 27, is to examine the refurbishment, including the installation of flammable cladding.

According to the Telegraph, this phase is said to be more complex than the first, which took 16 months to complete. Preparation for this phase has reportedly unearthed 200,000 documents and the phase will be split into eight “modules,” with 21 companies and 600 individuals named as “core participants.”

Among the modules, the areas that will be investigated include the refurbishment itself, the testing of the cladding, complaints from residents prior to the fire, the management of the building and the aftermath of it all.

Some estimates say that it could take Moore-Bick until at least 2023 to publish a final report. Only then would police and prosecutors get a chance to review the findings and then pursue charges, if any.

A few days into the second phase, after much finger-pointing, lawyers for Studio E, Rydon, the TMO and Harley wrote to Moore-Bick arguing that their clients could claim privilege against self-incrimination and not answer questions, noting that they would only speak openly if the attorney general gave an understanding that nothing they said would be used against them in criminal prosecution.

In late February, United Kingdom Attorney General Suella Braverman announced that she was granting the undertaking. In her letter to Moore-Bick, Braverman wrote that receiving “substantive answers” to questions in the probe is of an important public interest.

Therefore, the undertaking will cover people, will not impact the ongoing criminal investigation and will not jeopardize criminal prosecutions.

In early March, lead architect, Bruce Sounes, admitted that he had not read the Building Regulations covering fire safety in high-rises.

He said that he was “largely unaware there was specific guidance in Approved Document B for buildings taller than 18 meters and did not know that aluminum panels could melt.”

After Sounes admitted to not reading the regulations, inquiry lawyer Kate Grange asked what steps he did take to familiarize himself with the project and with Approved Document B.

Sounes pointed to the use of fire consultants and claimed that the design responsibilities should have fallen on design-build contractor Rydon.

However, the lawyer pointed to a document between Studio E and Rydon that specified Studio’s duties. They included: “seek to ensure that all designs comply with the statutory requirements” and “with other consultants, where appointed, develop the scheme designs, agree with the contractor the type of construction and quality selection of materials.”

In addition, it also came to light that the tenant management organization had breached regulations in the appointment of Studio E in the first place. Studio E, reportedly, deliberately deferred a chunk of its fees to stay under the threshold that would trigger an open public tender for design services.

The practice also admitted to having no experience in overcladding or refurbishing high-rises, meaning that it would’ve been unlikely that the firm would have won any public competitive procurement process.

Natalie Oxford, CC-SA-BY 4.0, via Wikimedia Commons

Separate officials with Studio E Architects spoke to the inquiry this week about the different disagreements on the envelope’s cavities as well as the type of insulation used in the project.

Instead, the Studio landed the job “on the back of its work for the local council on the linked Kensington Academy and Leisure Centre.”

Shortly after that testimony, meanwhile, Studio E associate Neil Crawford blamed the government for not amending the regulations on cladding systems when there were known problems.

Shortly before the hearing’s suspension, Studio E continued to testify, revealing that Sounes urged his client for the refurbishment to not show the fire brigade the fire safety plans because the brigade might support “a severe interpretation of the regulations.”

The inquiry was then paused on March 16 and then resumed at the beginning of this month.

The first testimonies after the hiatus revealed that the principal fire engineer for the tower’s refurbishment did not order a separate fire assessment of the cladding.

What Now

In the latest round of questioning, Sounes told the inquiry that he had originally wanted to use the non-combustible Rockwool insulation for the tower cladding.

However, engineering firm Max Fordham had put for a U-value target of 0.15W/m²K for the insulation, with a specification of 150-200mm.

Sounes said that the amount of Rockwool required would have pushed the cladding line out to around 450mm, which was “unfeasible” because of the targets, which is when the Celotex RS5000 was suggested.

Sounes was asked why the firm didn’t challenge the U-value target in order to install what it knew to be the safet material.

“We have done a lot of work with Max Fordham and they pride themselves as aspirational engineers […] they have done exceptionally sustainable buildings,” Sounes said. “The emphasis on passive sustainability was something we shared with Max Fordham over a number of years.”

Council also questioned how Sounes got to his 450mm estimation, as the inquiry’s own expert’s numbers estimated the thickness at around 250mm. Sounes replied that he used an online calculator on Rockwool’s website.

Finally, he was asked about his initial reaction to the Celotex suggestion, to which he replied that he didn’t have any concerns because the product is widely used and at the time was of the view that the product “didn’t burn it just charred and it was safe to use in cavities.”

Meanwhile, Crawford came under fire for disagreeing with a building control surveyor at the Royal Borough of Kensington and Chelsea, who insisted that the new wall structure needed to include fire-stopping materials to prevent flames from spread in between floors.

Surveyor John Hoban sent emails to that effect to the architects, noting that the materials should be able to stop spread for at least two hours, to which Crawford responded that that wasn’t needed and that the cavity barriers would suffice. (However, the inquiry has already found that the cavity barriers themselves were poorly fitted or missing altogether in some areas.)

The inquiry is slated to continue.


Tagged categories: Building envelope; Building Envelope; Cladding; Condominiums/High-Rise Residential; EMEA (Europe, Middle East and Africa); EU; Fatalities; Fire; Health and safety; Insulation; Lawsuits; Safety

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