Attic storage

I am in a top floor unit and would like to create attic storage accessible via a drop down ladder (non habitable).

A couple of questions….

Does this require a special resolution at an AGM, EGM or either? Would I be asking for exclusive use of the roof space, or for it to be put on title?

Do I need to purchase the space, or offer a reasonable monetary sum for the space?

Must the motion submitted to the meeting be put forward in the form of a by law covering all aspects of the space used, future maintenance, etc, or could it be more general? Any hints / tips on how the motion should be worded? I understand if a special resolution by law is voted on and passed it must then be lodged at the land titles office.

I am in Randwick Council, would this be considered an exempt /complying development as it is non habitable space?

Any advice would be greatly appreciated,especially from those who have been down this track before.

Thank you.