VIC Property Law - Purchasing Property Without Building Permit from Owners?

[Nikola]

Looking at buying a property to which the owners have added a pergola without having a building permit. Can I apply for a post factum permit without being fined under Property Law? Can I be forced to demolish it?

 

[Tim W]

1. Are you certain that it's not a complying work?
2. Is it an option to offer them, say, ten thousand less,
   being the cost of removing it, and replacing it with a compliant one?