TW – thanks for that additional detail.
I wouldn’t go in as hard as KWP, but I agree that it’s a bit of a conundrum particularly as the Owner concerned has not requested the O/C to make repairs to the roof; perhaps because they know that’s their responsibility (?).
I remain of the opinion that the burden of proof is with the Owner, but so far as the potential sale of the affected Lot is concerned, I’d suggest that in the first instance your O/C discusses the matter with that Owner; who knows, they may accept responsibility for or come to some agreement about the roof.
If that’s not forthcoming, then your O/C should wait until the a sale is advertised and then advise the selling Agent in writing that it “has no records of the extended roof above the courtyard ever receiving consent in accordance with Sect 65A of the NSW Strata Schemes Management Act (1996)”.
That form of advice is not stating that there is no consent, just that the O/C has no records in that regard, and provides the Owner a further opportunity to meet their burden of proof by providing anything that they have to the contrary, and concurrently puts the selling Agent on-notice to properly advise potential purchasers.
Then if as you predict, a new Owner of the affected Lot requests the O/C to repair the roof, at least there’ll be bargaining point to limit its liability for that and even to perhaps head some way down the path suggested by KWP – in circumstances where any Special By-Law to address the matter could not be retrospective without the prior written consent of the current Owner.