OK, so the question behind me asking.
AFAICR the minimum altitude is 100 AGL unless landing.
There are exceptions, but.....
A mate lives somewhere and he claims small jets fly over his place lower than .......
Well, he doesn't know the rules.
In the greater Sydney area - just for clarity.
I suggested he gets/uses Flight radar 24 to see who they are and at what altitude they are at.
I did mention that he may not see their ACTUAL altitude for the day's QNH but for the standard QNH.
But I guess if the plane says 500 feet over where he is: there will be questions asked of the pilot.
(Take screen shot and send it to the plane people.)