Zero lot dividing fence boundaries

Hi....
I’m having a really hard time finding out information about a dividing fence.
We have been living here for 5+ years (Spring Farm NSW)
And the dividing fence on the side of our garage stops before the garage starts. That side of the house we have plumbing pipes underground as well as he downpipes. Our neighbours have put an extension on the previous fence and it comes out past the front of our garage now... we can no longer reach our down pipes if for what ever they needed to be replaced. I Also believed a dividing fence on a zero lots in the Camden council stops at the back pf the garage and the wall of the garage makes up for the rest of the dividing wall? Can they really put up the fence giving us no access to our pipes now?
Can someone please help me out with some sort of clarity or guidance to what I need to do.

Hi Nicole

Did you get any answers in this issue ? I have a similar issue now and don’t know how to go about moving neighbours fence back to obtain access.

Thank you

Vicky