So, it seems that the problem are that engineers are specifying excessive requirements, and then there aren’t enough waterproofers so they are all pushing the prices up. One quote for our remediation was half of what would be charged to build a whole new block of units.
My reading of the rules is that bathrooms are exempt unless there is more than one dwelling, in which case the paper work needs to be done. I haven’t gone through all the rules, but one difficult requirement is that waterproofing has to be done as a single sheet. Much fun because the bathrooms in mystery strata have tiles to the ceiling, resulting in a big job, to fix what is needed which is probably just the base of the shower. Or is that interpretation correct?