Retaining walls

A retaining wall with green trees along the top.

In Queensland, a retaining wall is a structure designed to hold back soil or rock, preventing erosion and creating usable land on slopes or uneven terrain.  They are classified as a Class 10b structure under the National Construction Code. They may require building approval depending on their height, location and other factors.

Building approval for retaining walls

A retaining wall more than one metre high requires building approval. 

A retaining wall that is one metre or less may still need building approval if:

  • it's within 1.5 metres of a building or another retaining wall
  • there is a surcharge loading (driveway, footings, structures) over the zone of influence
  • it forms part of a swimming pool barrier (pool barrier compliance and certification will be required)
  • there is a fence on top, and the combined height is more than two metres above the natural ground surface.

If you're unsure if your retaining wall needs approval, contact a private building certifier.

Retaining wall building approval checklist

To check if your proposed retaining wall needs building approval, complete the Retaining wall building approval checklist.

A copy of your answers will be emailed to you for your records.

If your retaining wall needs approval or you need more information, contact a private building certifier.

Siting requirements for a new retaining wall 

  • The entire structure must be contained within the property boundary. This includes all footings, sub-drainage and sump drainage.
  • If a retaining wall, or the combined height of a wall and fence, exceeds two metres above natural ground surface and is within 1.5 metres of a side or rear boundary or within 6.0 metres of the road boundary, a QDC MP1.2 siting variation (Concurrence Agency Referral) must be lodged through your building certifier.
  • On corner lots, structures must not exceed one metre in height within the 6 metre by 6 metre truncation unless approved.

Find out more about placing a structure on your property.

Building near stormwater infrastructure

Council drainage easements and stormwater mains

Approval is required to build or alter surface levels within a Council drainage easement or to build over/near a stormwater main.

Sewer and water mains (Unitywater assets)

All applications to build over or adjacent to sewer/water mains must be referred to Unitywater for assessment. This is regulated under QDC MP1.4. Non-compliant proposals require Unitywater concurrence.

Find out more about placing a structure on your property.

Responsibility for the cost and maintenance of a retaining wall

A retaining wall is usually more beneficial to one property and is built on one property, so it is not normally a joint responsibility.

Where a wall is built on or across a boundary, the owner of the land on which the wall (or the relevant part) is located must maintain that portion.

If responsibility becomes a civil matter, the Queensland Civil and Administrative Tribunal (QCAT) may be able to assist. However, QCAT’s dividing fence process generally does not apply to retaining walls.

Seek independent legal advice if you are involved in a retaining‑wall dispute.

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