Thanks for that additional information Luke.
You’re right in that the information I initially provided seems to be in general alignment with what I now understand about the terrace owner’s proposal.
That owner will need to satisfy the requirements of the Owners Corporation (O/C) and be able to demonstrate that before the Heritage Council and your Local Council will consider their Development Application, so that’s why their proposal is now with your Executive Committee and Strata Manager.
The issues are complex, and the O/C will need some competent and practical advice, particularly with the complexities of exclusive use (perhaps unnecessary if no one other than the proponents could use the new areas), with the SBL provisions about who it is will be responsible for the ongoing maintenance and repair of the new areas, and the assessment of any payments to be made to the O/C in addition to those involved in it and the Strata Manager collating everything and convening the General Meeting.
The terrace owners will need to make you and the other owners fully aware of their proposal, because in order for a SBL to pass a minimum 75% of owners present at the Meeting both personally and by proxy need to vote in favour, with that percentage determined from the unit entitlement of those owners.
Good luck with it all, and remember there’s a lot of competent and practical information collectively available on FlatChat.