Approaches like this would work but are also a huge can of worms.
In most countries (and I'd expect to include Australia), there cannot be a blanket invasion of privacy - and it'd require a court order. The amount of paper would would be ridiculous, then what if I do that on my own, or I used a cousin to do it for me, for free?
> what if I do that on my own, or I used a cousin to do it for me, for free?
You and your cousin could decide to go and mud wrestle crocodiles, but we'd still ban opening an amusement park where that was offered to members of the public.
Seriously, who in their right mind is going to deny entry to an auditor making sure that your builder isn't an idiot?