Winston – the Strata Manager is correct in my opinion, as your Owners Corporation’s (O/C) approach should have been to seek an Interim Order to halt the Owner’s un-consented renovations as soon as it became aware of those.
So now your O/C has to play catch-up, and in my opinion the best way for it to do that would be for it to immediately write to the Owner and advise them that the works that they’ve undertaken (describe them specifically) place them in breach of Sects 65(A) and 116 of the NSW Strata Schemes Management Act (1996), and that it is their duty (use that word) to within 7 days either commence whatever repairs are necessary including but not limited to (list those) in order to return the common property to its original state or seek in writing the Owners Corporation’s consent to the entirety of their renovations, which it will retrospectively consider.
In that way, if the Owners seek written consent your O/C could at a General Meeting, as a demonstration of good faith, retrospectively consent to the Owner’s renovations with conditions, one of which would be that they, at their cost, repair all areas of the common property (as listed).
Conversely, if the Owners don’t within the timeframe allowed seek consent, and they don’t commence the listed repairs that are their duty despite the O/C’s offer in good faith, then that would in my opinion open the door for the O/C to invoke the provisions of Sect 63(4) as the only clause of that Section that’s relevant to your O/C’s situation.
The better as opposed to the best option (i.e. the Orders) would be to encourage the Owners to seek consent under Sect 65(A), as in that way the O/C wouldn’t have to seek access to the Owner’s Lot and/or chase them for the recovery of its costs in the NSW Civil and Administrative Tribunal, where it could still end up after Mediation anyway; which is why it’s been acting in such “good faith”.
Of course your O/C could seek resolution via Mediation with the assistance of the NSW Department of Fair Trading straight away, but again in my opinion a letter and a delay of around 7 days for a reaction is not too long for it to seek-out a better and quicker solution.