Retaining Walls

This information sheet relating to retaining walls is intended as a guide only.

What is a Retaining Wall?

A Retaining Wall is a wall or structure designed and constructed to support soil at a slope steeper than can naturally be supported.

Whilst retaining walls are primarily designed to support soil, they may also be placed under a “surcharge” from other factors such as buildings, footings, vehicles, driveways and wind loads on dividing fences.

Most walls are designed to support soil only, these walls are termed “non-surcharged” It is very important to ensure the wall you intend to construct is designed to support any surcharge that may be placed upon it.

A fence should not be used to retain soil unless it is designed to do so.

When is a Retaining Wall Required?

When an embankment with a slope ratio that exceeds those described in the following table must be retained or appropriately stabilised.

Responsibility for Construction

The owner who alters the natural lie of the land is responsible to provide a retaining wall.

However, where both property owners alter the levels, they would be jointly responsible. The sharing of costs for the retaining is a civil matter that must be negotiated between neighbours.

If both parties cannot reach an agreement as to who is responsible for retaining the difference in ground levels it may be necessary to seek legal advice.

Retaining Walls are not covered in the Dividing Fence Act.

Is Council Building Licence Approval Required?

A Building License is required where a proposed retaining wall exceeds 500 mm in height or located within 1m of a boundary.

When the wall is situated on a common boundary, neighbours consent is required (forms are available at the Council Offices).

For retaining walls that exceed 500 mm in height the City requires that such walls are designed by a Structural Engineer, therefore applications are to be accompanied by signed Structural Engineer’s drawings.

Positioning of Dividing Fences and Retaining Walls

A dividing fence up to 1800mm high can be positioned on the higher side of a retaining wall which abuts a common boundary.

Retaining walls abutting a common boundary are to be constructed entirely within one property, they are not permitted to straddle the boundary.

Building License Submission Requirements For Retaining Walls click here

For more detailed instructions please contact the City Building Surveyor on 99 566 600