Put to together a series of motions for your next EC meeting (or, if there aren’t any, to the secretary/chair/strata manager).
Each of these motions should be backed by a reference to your by-laws or strata law.
For instance: “The EC should issue a notice to comply against the owner of lot XXX for repeated breaches of By-law x.” You would, of course append pictures or statements from other owners to back your action.
In the case of the roof space, it would be a motion that the EC pursues the owner under Section 116 for interfering with common property.
Let’s assume that the EC or office bearers do nothing about these motions for two months. You then move on to a section 138 action against the Owners Corp, asking an adjudicator to force the EC or whoever to take action.
However, before you do anything, it may be worth talking to a specialist strata lawyer.
This is what section 138 says:
138 General power of Adjudicator to make orders to settle disputes or rectify complaints
(1) An Adjudicator may make an order to settle a dispute or complaint about:
(a) an exercise of, or a failure to exercise, a function conferred or imposed by or under this Act or the by-laws in relation to a strata scheme, or
(b) the operation, administration or management of a strata scheme under this Act.
(2) For the purposes of subsection (1), an owners corporation or building management committee is taken to have failed to exercise a function if:
(a) it decides not to exercise the function, or
(b) application is made to it to exercise the function and it fails for 2 months after the making of the application to exercise the function in accordance with the application or to inform the applicant that it has decided not to exercise the function in accordance with the application.