This would be a perfect opportunity for you to persuade your Owners Corp to adopt the State Government's “Memorandum of Understanding” which seeks to clarify all these significant but small issues without going to the expense of writing and passing a new by-law every time someone wants to make a minor adjustment to their apartment.
You'll find an outline of the Memorandum HERE. It clarifies so many niggly issues that every strata plan in NSW really should think about adopting it (and you can modify it to suit your specific needs) – but remember, it doesn't necessarily apply if you don't formally adopt it.
Have a look then have a chat with your strata manager and EC chairperson.