Having a dispute with your neighbour can make living in your own home quite uncomfortable, even though most arguments start from harmless situations. However, the most common dispute is usually regarding the boundary between your property and your neighbour’s. Shared fences are unavoidable but there are ways to settle boundary disputes amicably:

• If you or your neighbour want to add a boundary fence then you need to construct one by law.
• Property lines can be measured easily through records usually kept at the local council.
• Approach a boundary dispute in a professional manner.
• Be prepared to compromise if it will help you both come to an arrangement.

If negotiations fail make sure you do everything as the law states - don't be the one in the wrong.

In the case of adding boundary fencing or undertaking fencing repairs, you can simply send a written notice to a neighbour. This should be your last resort: if the neighbour does not reply to a fencing notice and the dispute continues, you and your neighbour will have to appear before court to settle the matter.

Source: http://www.homeimprovementpages.com.au/article/dealing_with_boundary_disputes