When you gave your written offer did you specify “subject to building inspection”? Or pest inspection, finance or otherwise?

Did you not discuss bringing a builder or qualified/experienced friend through prior to offering?

I mean if you are only 8 days from settlement wouldn’t you have already put down a deposit to the vendor and or sellers agents trust? And has your conveyancer / solicitor said you will be able to get that deposit back?

This entire thing is so scary sounding, if i were in your position right now i would be contacting sellers agent and telling the vendor, opposing conveyancer and estate agent that i will be revoking the offer and not settling, and that you are not opposed to making a new offer “subject to building inspection” if the vendor can provide details on the extension, illegal works or otherwise just give details on the works, so my offer can reflect the hazards your obviously hiding.