Retaining Walls

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 stress from other factors such as buildings, footings, vehicle loads, driveways, water, and wind loads on dividing fences.  

Prior to construction of any retaining wall, an application for a building permit may be required to be lodged with the Shire. 

Who is responsible for a Retaining Wall?

The natural ground level at the boundary of a lot must be maintained. If a person excavates below the natural ground level or fills above the natural ground level, then that person has an obligation to provide a suitable retaining wall or durable embankment, to ensure the natural ground level and any existing surcharge load at the boundary is maintained.

In some instances, adjacent owners sharing a common boundary may need to proportionately contribute to the construction of a retaining wall(s) or durable embankment(s).

When is a Building Permit required?

All retaining walls greater than 500mm in height require a building permit prior to works commencing.

Retaining walls less than 500mm high also require a permit where they:

  • Encroach beyond the boundary of the works land;
  • Adversely affect the adjoining lots by reducing the bearing capacity of the land;
  • Damage or reduce the structural adequacy of a building or structure on the land;
  • Change the natural site drainage in a way that reduces the effectiveness of the drainage of the land or existing or future buildings on the land; or
  • Support any other structure such as a wall, fence, swimming pool or building

What documents do I need for my Building Permit Application?

  • Completed application form, either a BA1 (building permit application - certified) or BA2 (building permit application - uncertified). Application forms can be found here 
  • Applicable fees (please see fee schedule)
  • Certificate of Design Compliance (BA3) (only required if submitting a BA1 – Certified Building Application)
  • Site plan at a minimum scale of 1:200 showing:
    • Setbacks from the lot boundaries and all other buildings on the property, and
    • Dimensions of the proposed structure and indicate the top and bottom of the retaining wall levels in relation to natural ground levels
    • Distance from effluent tanks, leach drains and related systems (where applicable)
  • Engineering details signed by a structural engineer
  • Sections 
  • Elevations 

This list is not exhaustive and further information may be requested. For more information on the building approvals process please check out the Building Approvals Process Guide

When is Planning Approval required?

  • Where a retaining wall exceeds 500mm in height from natural ground level and does not meet the required side and rear setbacks under the Residential Design Codes (Variation 1) or
  • Where a retaining wall exceeds 500mm in height from the natural ground level and is within the front setback

To confirm whether you require Planning/Development approval, please contact Planning Services on 9526 1111 to discuss your specific requirements.  Please find a link below to further Planning information and access to a Development/Planning Application Form

Please Note:

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

Retaining walls shall be constructed entirely within one property. They are not permitted to straddle the boundary

For further information, please contact Building Services on 9526 1111 or by email at