Just to add to my previous comments and Scotti’e observation below, it is worth noting that the section of the strata Act dealing with exclusive use by-laws and the like, assumes that the Owners Corp will take responsibility for altered common property unless it is otherwise specified in the by-law.
This is not the same as someone having made unauthorised changes and then selling without telling, but the intention is clear – if no one else takes responsibility then it falls to the Owners Corp in the absence of any legally binding document to the contrary.