Buyers have the option of buying subject to building/pest inspection if it's auction has to be done prior to.
I *think* Sydney the owner has to supply such reports, I think it's better the buyer does it and pays for it often otherwise buyers are sceptical and say "of course the owners report says it's fine" even though it is completed independently.
Not a big issue out here 80% of the transactions are properties under 7 years old and still covered by statutory warranties.
I recommend buyers to do them regardless, it's Upto them though.