Re: Don't give me no static ...
"then someone thought aluminium, being metal, was also safe and, more crucially, £300,000 cheaper"
Then they saved £5k on £80k worth of aluminum composite panels by specifying the flammable ones instead of the flame retardant ones (2 quid per panel cheaper over 2500 panels)
Then they saved about the same on the insulation under the cladding by specifying a plastic (flammable) type instead of rockwool ("But it's got better insulation properties" - yeah about the same as an extra 1/2" of rockwool)
Then the builders saved a bit of money by either not installing firestopping at each level or somehow compromising it during installation.
Then they saved even more by running an exposed gas supply line up the stairwell (fire escape) with an exposed spur into each corridor instead of doing it properly by putting it in the service riser and keeping the apartment supply pipes out of the escape corridors. ("We were going to box it in" - yeah, with wooden non-gastight boxing)
The last item constitutes "setting a man trap" and is why so many people died despite past cladding fires having very low casualty rates - they couldn't get out because apart from the smoke, by the time they tried the fire escape was itself on fire.
And that's quite apart from the issues of compromised fire doors and blocking off the access road so that brigades couldn't easily get access to the building.
Grenfell is going to be held up in civil engineering classes for decades as an example of how a safe design can be hopelessly compromised and why bridging firebreaks and then adding bridge protection built around a single point of failure is a bad idea, especially when you expect that SPOF (the firestopping) to be installed by minimum wage unqualified, poorly trained and badly supervised staff.