Fire-resistant zinc cladding approved by residents of Grenfell Tower was replaced in the refurbishment contract with cheaper aluminium panels to save £293,368, according to documents seen by the Guardian.
A list of amendments to the £9.2m contract between Kensington and Chelsea Tenant Management Organisation (KCTMO) and Rydon, the builder for the refurbishment of the 24-storey tower, reveals that the saving was made after tender by fitting “cassette fix aluminium cladding in lieu of zinc cladding”.
In 2012, Studio E Architects proposed zinc cladding with a mineral-rich “fire-retardant polyethylene core”, a decision approved by residents, according to planning papers.
However, it was replaced in 2014 with cheaper aluminium cladding with a polyethylene core which has since proved combustible in government tests.
A tolerance was set for fire performance on the project and both products were within that range, the Guardian understands, but the aluminium panels were considered more combustible. Both products were certified according to the European fire resistance standard. The aluminium panels received a worse rating in terms of the amount of smoke they would emit.
Other savings listed include the removal of all external landscaping works, saving £428,000, and changing window surrounds from birchwood to MDF or softwood in a further £117,000 cut.
The aluminium cladding is suspected of having helped spread the fire that claimed at least 80 lives.
It emerged on Friday that 149 tower blocks in 45 local authority areas have failed tests on the flammability of their cladding. The number of at risk buildings has risen steadily since the government ordered a full review of high-rises around the country, and there is still a 100% failure rate in fire safety tests.
The Guardian has also learned that representatives of the KCTMO and the council’s planners were shown a mock-up of the cladding system on site in the summer of 2014.
Minutes of a progress meeting on 15 July 2014 attended by representatives of KCTMO, its project agent, Artelia, and Rydon, the contractor, suggest that the concerns they raised did not relate to safety but design issues, including the colour.
The minutes, seen by the Guardian, recorded: “Rydon have completed the mock-up for the cladding and it was confirmed that the planners are viewing the colours and fixing detail on 17 July … The initial feedback on the cladding, following a walk around prior to the meeting, is that the vertical sections need design work.”
It added in a post-meeting note: “The initial feedback from the planners is that they would probably prefer the champagne to brushed aluminium and they were not that keen on the face fix.”
The minutes also suggest that even though the design for the cladding was well under way, fire consultants had yet to be appointed.
It said Rydon would appoint “other consultants (to include fire, DDA [Disability Discrimination Act], acoustic, etc, after the main subcontractors are on board”.
There was further evidence of the drive to cut costs in an “urgent nudge email” KCTMO’s project manager sent to Artelia, its cost consultant, about cladding prices. It said said: “We need good costs for Cllr Feilding-Mellen and the planner tomorrow at 8.45am!”
Rock Feilding-Mellen is chairman of Kensington and Chelsea’s housing committee. Artelia replied with three options including that “fully cassette-fixed cladding” would save £293,368.
Artelia, a French-owned company, fulfilled several roles for KCTMO. It was its agent with a duty “to coordinate the development of the requirements for the project with the client and their professional advisers, and to act as the contract administrator”.
Until April 2015, Artelia was also “a key project adviser” on “construction health and safety risk management matters”. It also acted as quantity surveyor “primarily to advise on the cost of the project, [and] prepare tender and contract documentation”.
The document containing proposed cost cuts to bring the refurbishment budget down from £9.25m to £8.65m was issued by Artelia. In July 2014, KCTMO asked it to provide costings for the three different types of cheaper cladding.
Artelia said on Friday none of its roles involved “the design of the project, or specification and/or approval of materials”.
It declined to discuss the documentation citing “a duty of confidentiality in its contract with KCTMO”.
Untangling responsibility for decisions on the project remains complex. The number of companies and organisations that Scotland Yard detectives investigating the disaster know so far to have played a role in the refurbishment is more than 60. The chief executive of KCTMO, Robert Black, stood down on Friday to “concentrate on assisting with the investigation and inquiry”.
KCTMO declined to comment on the material swap. A spokesperson said: “As we continue to cooperate fully with the investigation into the tragic events at Grenfell Tower, Kensington and Chelsea Tenant Management Organisation has to put on hold all requests for disclosure of relevant information.
“We recognise our responsibility to ensure that the investigative process is not hampered or undermined in any way.”
Police said they were considering manslaughter charges in relation to the fire as they revealed that the cladding tiles at the building had failed safety tests.
The leaders of Kensington and Chelsea council have been accused of shameful behaviour after shutting down the first cabinet meeting since the disaster after attempts to block the media from the meeting failed.
The council, whose leader Nick Paget-Brown also quit on Friday, wanted the meeting held behind closed doors but a group of media organisations including the Guardian obtained a high court order preventing the council from banning journalists at about 6pm on Thursday, half an hour before the meeting was scheduled to start.
The doors were finally opened when the meeting was under way, although those bereaved by the disaster and residents were not allowed in.
But Paget-Brown then adjourned the meeting, saying it could not continue with journalists present as this could prejudice the official inquiry, which will be led by Sir Martin Moore-Bick, a retired court of appeal judge.
The Labour councillor Robert Atkinson told BBC Radio 4’s Today programme the brief session had descended into “utter chaos”, adding: “I am ashamed of the way in which the council proceeded. They have been hiding from residents; they have been hiding from backbench councillors for over a week.”
Kensington and Chelsea council has said it will cooperate with any investigation into the fire.