The Department of Communities and Justice has information about the law on dividing fences. It also gives you information about boundary disputes and retaining walls. It can help you if:

  • you want to build, fix or replace a dividing fence
  • you have a disagreement with your neighbour about a dividing fence​
  • you have a disagreement with your n​eighbour about where the common boundary between your properties is
  • you want to build a retaining wall.​

https://www.lawaccess.nsw.gov.au/Pages/representing/lawassist_fences/lawassist_fences.aspx