The acoustic engineer may be right about the BCAs but they are not the only factor in a correct decision being made. The objective test is whether or not the noise transmitted by these tiles disturbs the peaceful enjoyment of your lot. I can’t believe in this day and age that we are still getting these clowns on the CTTT but is seems the last of the fruitloops are still there. There a re plenty of previous case under strata law where the actual noise and not some technical test by an acoustic engineer has been accepted by adjudicators.
My advice to you would be to talk to an experienced strata lawyer right now. Our sponsors Makinson d’Apice are very experienced in this field, as are Grace Lawyers, David Bannerman, David le Page and others. It might cost you a couple of thousand dollars but they will get you the best result possible and will cut through all the BS at the CTTT and force them to apply the law. The Strata Schemes management Act says nothing about building standard – only about the peaceful enjoyment of lots.
And the order that you originally got is actually spot on – they are being told to cut down the noise and that means the only criterion of whether or not this has been complied with is whether or not you are still disturbed by it.
If your neighbours complain about having to lay down wall-to-walll carpet, remind them of their own words: “bad luck – that’s apartments for you!”