A fire safety company was left out of planning discussions about Grenfell Tower's deadly cladding, an inquiry has heard.
Exova said criticism of it is "unjustified" because it was not consulted about the combustible materials that eventually coated the concrete exterior of the 25-storey block, said the firm's counsel Michael Douglas QC.
Mr Douglas told the inquiry into the disaster that the company was hired to give fire safety advice on early plans for the block's refurbishment, but after Rydon became the main contractor in 2014 the project "changed fundamentally".
Rydon did not "prolong or continue" Exova's involvement and appeared to consider fire safety as "building control's responsibility", he added.
Regarding advice Exova gave on plans which said proposed designs would have no "adverse effect" on fire safety, he added: "None of those drawings contained any reference whatsoever to cladding and were concerned primarily with the revamp of the lower four floors."
Mr Douglas said inspectors were not involved "in any discussions about cost or appearance" or "about the potential materials changing to aluminium composite material".
The second phase of the inquiry into the disaster is considering how the building came to be covered in flammable cladding, which the probe earlier found was the "principal" reason for the rapid spread of flames.
Mr Douglas said: "When Rydon became involved they didn't prolong or continue our engagement.
"Exova was never asked any advice except in very small and specific ways after Rydon became main contractor and main designer.
"I'm not trying to pass the buck. But a question worth looking into is how Studio E (the main architects) never said to Exova, 'excuse me, we're planning a cladding system, will you please advise us or update your report?'. That never happened.
"For these reasons we submit that criticism of Exova is unjustified."