The building control system and processes used by the Royal Borough of Kensington and Chelsea were fundamentally flawed and failed to properly assess the planned refurbishment of Grenfell Tower, according to an expert witness for the inquiry.

Beryl Menzies identified a litany of failures including not asking about the tower’s cladding system or the materials to be used, failing to spot out-of-date and contradictory information; and failing to recognise that no cavity barriers had been indicated in initial designs to seal the cavities or opening in the walls.

Ms Menzies said that she believed the initial full plan application to the building control department should have been rejected before work started. She said the fire strategy from the refurbishment’s fire engineer Exova “did not address the actual proposals” put forward.

Ms Menzies described the role of building control as the “third line” of protection for a construction project and that it should ensure the construction meets building regulations.

When asked about the performance of John Hoban, the council’s building control officer who worked on the Grenfell Tower project, Ms Menzies said she felt that he was struggling and that he was badly managed.

By Patrick Mooney, Editor