Dan – whilst the Owners Corporation (O/C) can require the Lot Owner to undertake the works, I’m of the opinion that as its Common Property (CP) is involved the O/C should commission and supervise the entirety of the works, with entry if necessary being obtained under the provisions of Sect 65, and with the O/C’s total costs (i.e. for works on its CP and any required on/for the Owner) being recovered in accordance with Sect 63. Of course each party could attend to their own works, but as that’s generally neither cost effective nor desirable my definitive answer to your question is… the O/C.
However (there’s always at least one in Strata) whilst Sect 65 refers the an O/C entering a Lot to undertake works that are required under the Strata Schemes Management Act (SCMA), and Sect 63 permits the O/C to recover its costs of undertaking those works where those would otherwise be the “duty” of the Lot Owner, and strident advice on both of those may well “encourage” those past renovators in your Plan to agree to the O/C’s proposed Special By-Law (SBL), if they’re not convinced and that SBL fails to pass the vote at your AGM, then you could hit the proverbial (renovated) brick wall.
Why?
Well if that SBL fails to pass then I can’t see that same group of Owners (as the O/C) applying for Orders under Sect 140 – which I see as the approach most applicable if the O/C’s approach was that it IS prepared to retrospectively consent to all past renovations IF the Order makes the current Owner/s of affected Lot/s responsible for the maintenance and repair of those.
I don’t wish to be personally critical, but on a generic basis I have to observe that after almost 4 years on this Forum I can’t understand how Owners can still undertake substantial renovations to their Lots that involve the CP with no other Owners being aware of the requirements for obtaining prior consent to those, or even seeking guidance or advice from their Strata Manager if and until it’s too late!
Fingers crossed that your SBL passes and that your Strata Manager has both the knowledge and the commitment to bring all those past renovators into the fold.