If a neighbour wants to put up or replace the fence on your shared boundary, can they just do it? In New South Wales the short answer is no, not for a shared dividing fence, and not without giving you notice first. The rules sit in the Dividing Fences Act 1991 (NSW), which treats a boundary fence as a shared responsibility between the two adjoining owners. Knowing how it works keeps a fence project neighbourly and stops a small disagreement turning into a formal dispute.
Your neighbour cannot act unilaterally on a shared fence
A dividing fence separates two properties along the common boundary, and both owners generally benefit from it. Under the Act, the two owners are usually liable to share the cost of a sufficient dividing fence in equal proportions. Because it is a shared cost and a shared structure, your neighbour cannot simply build or replace it and hand you a bill without going through the proper steps.
The formal step is a fencing notice. If a neighbour wants you to contribute to fencing work, they serve you a written fencing notice setting out the proposed work, the type of fence and the estimated cost. That notice starts a conversation, it does not force an outcome. You are entitled to have a say on the type, standard and cost before anything is built.
There is a narrow exception. Where a fence is damaged or destroyed and there is an urgent need, for example to keep a pool enclosed or contain an animal, an owner can carry out urgent work and then seek a contribution afterwards. Outside genuinely urgent situations, the notice process applies.
What a "sufficient" fence means, and who pays
The Act asks owners to share the cost of a sufficient dividing fence, which is a fence that is reasonable for the two properties given the area and how the land is used. If one owner wants something dearer than a sufficient standard, a premium material or extra height for their own reasons, they generally cover the difference themselves rather than splitting it.
Cost sharing is where most disagreements start, so put the agreement in writing before work begins: who pays what, what is being built, and who looks after maintenance afterwards. A simple written record prevents the "that is not what we agreed" argument down the track.
Sort out the boundary before anyone builds
A fence built in the wrong spot causes more trouble than almost anything else. If there is any doubt about where the boundary sits, and there often is when an old fence has drifted or there is no fence at all, engage a registered surveyor to mark the true line. It is far cheaper than moving a finished fence or unwinding a boundary dispute later. If a tree or structure sits on the line, your council can advise where the fence should go.
Talk to your neighbour first
Most fence projects never need a tribunal because the owners talk it through early. A few things make that conversation go well:
- Raise it before you order anything, at a relaxed time rather than in passing over a stressful moment.
- Be clear about why you want the fence, whether it is privacy, keeping a dog in, or replacing something falling down.
- Listen to their view on materials, height and cost, and look for the option you both accept.
- Keep it calm and factual, and put whatever you agree in writing.
Approach the discussion prepared to pay the full amount yourself if the fence is your idea and your neighbour is not fussed about it. That mindset keeps the negotiation honest and takes the heat out of the cost question.
If you cannot agree
When talking does not get there, NSW has a clear path. Free mediation is available through Community Justice Centres, and a neutral mediator often resolves a fence dispute without any formal application.
If mediation does not settle it, either owner can apply for a fencing order once a fencing notice has been served at least one month earlier. The application goes to the Consumer and Commercial Division of the NSW Civil and Administrative Tribunal (NCAT) or to the Local Court, both of which can make the same orders about what fence is built and how the cost is split. NCAT tends to be less formal and starts with a conciliation. Legal Aid NSW publishes step by step guides on preparing a fencing notice and a fencing order application, and is worth reading before you lodge anything.
The takeaway
A shared boundary fence in NSW is a joint decision. Your neighbour needs to give you a fencing notice before expecting you to contribute, and you have a genuine say on what gets built and what it costs. Confirm the boundary with a surveyor if there is any doubt, agree the cost split in writing, and keep the conversation civil. If it stalls, free mediation through a Community Justice Centre comes first, and NCAT or the Local Court is there as a last resort. Rules can change, so check the current position with a legal service or your council if a real dispute arises.