Jimmy, the links you shared and your elaboration on the issue are appreciated. I was wrong and my strata mgr, whose view seemed to make sense, in the context of wooden floors being secretly installed by a previous unit owner, which are responsible for noise transmission to others, means that if the OC or NCAT insists that the insulation needs to be replaced, it would be the current owner and not the OC who would have to pony up the dosh. Interesting indeed.