Who Is Responsible for a Retaining Wall Between Neighbours in Queensland?

The Neighbourhood Disputes (Dividing Fences and Trees) Act 2011 sets out neighbours' responsibilities for dividing fences and trees. It does not make neighbours jointly responsible for retaining walls. The Act defines a dividing fence as a fence on the common boundary of adjoining land, and the term fence does not include a retaining wall.

In practice, Queensland councils and the Queensland Civil and Administrative Tribunal (QCAT) apply a simple principle: responsibility for a retaining wall generally rests with the landowner whose land the wall supports, because that owner has the benefit of it. If a wall was built so one owner could have a level building pad, that owner is normally the one responsible for it.

A dividing fence benefits both properties. It marks the boundary, provides privacy and keeps pets and children in. Because both owners gain, the Act generally splits the cost of a sufficient fence equally, unless they agree otherwise.

A retaining wall is different. It exists to hold back soil, usually because one lot has been cut down or built up compared with the other. The higher lot is supported, while the lower lot may gain very little. QCAT has stated that there is no power under the fencing provisions to order neighbours to contribute to the cost of a retaining wall in the way it can for a fence.

That does not mean the neighbour has no obligations at all. It means those obligations come from different places: the rules on boundaries, ownership of the land, building and planning law, and general neighbour law.

QCAT decisions on neighbourhood disputes show a consistent pattern, although every case turns on its own facts.

In one dispute, the Tribunal considered a sleeper retaining wall that had to be replaced. It found that the wall was entirely for the benefit of one owner, so its remediation was that owner's sole responsibility, even though the wall had been in place before the owner bought the land. A later decision repeated the position that the party who has the benefit of the wall should be responsible for its maintenance.

QCAT also recognised a link between fences and walls. Where a dividing fence sits on top of a retaining wall, and the fence cannot be repaired or replaced without work on the wall, the Tribunal can make orders about the fencing work that include the retaining wall work. This is a limited power. It does not turn the wall itself into a shared structure.

Because these outcomes depend on the facts, they are guidance rather than a guarantee. If a significant sum is involved, get legal advice.

Ownership and responsibility are related but not identical. A wall is generally owned by the person whose land it sits on. If it straddles the boundary, ownership and obligations become more complicated.

The City of Gold Coast notes that only an identification survey can establish who owns a retaining wall between two properties, which is the owner of the land on which the wall is located. If you want to report a retaining wall to council, you need to attach an identification survey. Do not rely on a fence line, a garden bed edge or what the previous owner told you, because boundary lines are often not where they appear to be.

This table is a general guide only. The result in your case can differ.

Responsibility is not only about who pays to build the wall. It also includes what happens when something goes wrong.

The City of Gold Coast states that stormwater from retaining wall work must be piped to the kerb or the stormwater system and cannot be concentrated onto a neighbour's property. If an owner changes drainage in a way that damages the neighbouring land, or excavates close to a boundary and undermines support, that owner may be liable for the damage and for repairs.

On the other side, an owner who ignores a failing wall that is threatening a neighbour's property can also face a claim. Where a wall is unsafe, councils can issue notices requiring the owner to fence off the area, engage an engineer, obtain building approval and have the wall rebuilt by a licensed builder.

Who pays is a separate question from who needs approval. Replacing or rebuilding a wall over 1 metre, within 1.5 metres of a building, or carrying surcharge loading needs building approval from a private certifier, and the owner of the wall is normally responsible for obtaining it. A neighbour cannot be forced to share the cost of an unapproved wall, and an unapproved wall can create bigger problems later.

If your neighbour is building a wall on or near your boundary and you are worried about its safety or position, you can raise it with council, but expect to provide a survey and details of your concerns.

1. Take photos and notes. Record cracks, leaning, bulging and soil movement with dates.
2. Get an engineer's inspection. An independent assessment shows whether the wall is unsafe and what repairs are needed.
3. Order an identification survey. It establishes where the boundary and the wall are.
4. Talk to your neighbour early. Share the engineer's report and suggest a practical way forward.
5. Put it in writing. A friendly letter or email recording what you discussed protects both of you.
6. Try mediation. Queensland's dispute resolution centres offer free neighbourhood mediation.
7. Consider QCAT. The Tribunal handles minor civil disputes, including dividing fence disputes up to $25,000, but treat it as a last resort.

If the wall is dangerous, do not wait for the dispute to settle. Keep people away from the area and seek urgent advice.

Even where the law does not require a contribution, many neighbours choose to share the cost when both benefit. A written agreement avoids confusion later. It should cover:

• What work will be done and to what standard
• Who will engage the engineer, certifier and contractor
• The agreed cost split, with quotes attached
• Access to each property during construction
• Who will maintain the wall afterwards

Remember that agreements between current owners do not necessarily bind future buyers, so keep records and tell any purchaser about them when you sell.

If you are buying, ask for the building approval, the engineering documents and the final inspection certificate for any significant wall. A wall that was built without approval, or that is clearly failing, can become your problem the day you settle. If you are selling, having the paperwork ready makes the sale smoother and gives buyers confidence.

• Speak to your neighbour before you start work, as council also advises
• Keep the wall and its footings within your own land, with at least 600 millimetres from the side boundary where possible
• Use an engineer and a licensed contractor for any substantial wall
• Provide proper drainage and a lawful discharge point
• Keep approvals, plans and certificates in a safe place
• Inspect the wall regularly, especially after heavy rain

Do neighbours have to share the cost of a retaining wall in Queensland?
Not automatically. The fencing law does not apply to retaining walls, and responsibility generally rests with the owner who benefits from the wall.

Who pays when a retaining wall between two properties collapses?
It depends on who owns and benefits from the wall and what caused the failure. An engineer's report and a survey are usually the first steps.

Can QCAT order my neighbour to pay for a retaining wall?
QCAT has no general power to order cost sharing for a retaining wall, but it can make orders about fencing work that includes wall work if the fence repair depends on it.

Can I remove a retaining wall on my neighbour's side of the boundary?
No. Removing or altering a wall that supports neighbouring land can cause damage and liability. Speak to an engineer and your neighbour first.

How do I find out who owns a retaining wall?
Order an identification survey. It shows whether the wall sits on your land, your neighbour's, or across the boundary.

This article is general information only and is not legal advice. Retaining wall disputes depend on their facts, so speak to a lawyer, your council or a dispute resolution centre about your situation.