Do You Need Council Approval for a Retaining Wall in Western Australia?

Understanding WA's retaining wall approval requirements is critical before starting your project. Western Australia has the lowest threshold in the country — walls over just 0.5 metres need a building permit.

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Western Australia Retaining Wall Rules at a Glance

Walls Over 0.5 Metre

A building permit is required from your local council or a private building surveyor. This is the lowest threshold in Australia. Engineering certification from a practising structural engineer is also required.

Permit Required

Walls Under 0.5 Metre

Generally exempt from building permit requirements, but may still require approval near boundaries, when supporting surcharge loads, in special control areas, or near infrastructure and services.

Usually Exempt

WA Building Commission

The Building Commission regulates all building work in Western Australia under the Building Services (Registration) Act 2011. Builders must hold appropriate registration to carry out retaining wall construction.

Registered Builders

Engineering Required

Walls over 0.5 metres need structural engineering design by a practising structural engineer. The engineer designs the wall, specifies materials and footings, and certifies compliance on completion.

Engineer Certified

Planning Approval

Some retaining walls require planning approval in addition to a building permit, particularly in heritage areas, bushfire-prone zones, flood areas, or for walls significantly changing ground levels near boundaries.

Check Overlays

Boundary Walls

Retaining walls on or near property boundaries in Perth may require neighbour notification and additional approvals. The Dividing Fences Act 1961 (WA) governs boundary fence and wall obligations between neighbours.

Neighbour Notice

The Retaining Wall Approval Process in Perth

Engage an Engineer

Hire a practising structural engineer to design your retaining wall. They will assess your site, Perth sandy soil conditions, and design requirements, then produce engineering drawings and specifications.

Apply for Building Permit

Lodge your building permit application with your local council or a private building surveyor. Include engineering drawings, site plans, and the required forms and fees ($300-$1,000+).

Receive Permit

Wait for your building permit to be issued (10-25 days private surveyor, 20-35 days council). Do not commence construction until the permit is received — building without a permit is illegal in WA.

Build & Certify

Your registered builder constructs the wall per the engineering design. On completion, the engineer inspects and provides a certificate of compliance, and the building surveyor issues the occupancy permit.

WA Building Commission Requirements

The Western Australian Building Commission oversees all building work in WA under the Building Services (Registration) Act 2011. Builders performing retaining wall work must hold appropriate registration with the Building Commission.

For domestic building work valued over $20,000, a registered builder is required. For work between $7,500 and $20,000, a registered building service contractor is sufficient. Using an unregistered builder is illegal and voids any statutory warranty protections under the Home Building Contracts Act 1991.

You can verify any builder's registration status on the WA Building Commission online register at dmirs.wa.gov.au. Always check before signing a contract. A registered builder will also carry mandatory insurance, including home indemnity insurance for projects over $20,000.

For guidance on selecting the right builder, see our how to choose a retaining wall builder guide, or use our Find a Builder tool to get matched with verified, registered contractors in Perth.

WA Builder Registration Checklist

✓Verify registration on dmirs.wa.gov.au
✓Check registration is current and not suspended
✓Confirm registration class covers retaining walls
✓Ask for registration number before signing
✓Ensure home indemnity insurance is in place (over $20k)
✓Get a written contract for all work
✓Check for any disciplinary history

WA Registered BuilderHome Indemnity InsuredWritten Contract

Engineering Certification Requirements

In Western Australia, retaining walls over 0.5 metres high require structural engineering design and certification. This must be provided by a practising structural engineer registered with Engineers Australia or holding equivalent qualifications.

The engineer performs critical functions specific to Perth conditions: they assess your site's sandy soil (prevalent across Perth's coastal suburbs), limestone content, water table proximity, and any surcharge loads. They then design the wall structure, produce construction drawings, and certify on completion that it was built to specification.

Engineering certification typically costs $500-$1,500 depending on wall complexity. While this adds to project cost, it ensures your wall is structurally sound and legally compliant. For more detail, see our when do you need an engineer guide.

What the Engineer Provides

✓Site assessment and soil analysis
✓Structural wall design calculations
✓Construction drawings for builder
✓Footing and drainage specifications
✓Material specifications
✓Certificate of structural adequacy
✓Compliance certification for council

Perth-Specific Approval Considerations

Perth's unique conditions — sandy soils, limestone subgrade, and Mediterranean climate — create specific challenges for retaining wall approvals.

Sandy Soil Considerations

Perth's predominantly sandy soils (Bassendean and Spearwood sands) require specific footing designs. Engineers must account for lower bearing capacity and potential for undermining during heavy winter rains.

Limestone Subgrade

Much of Perth sits on limestone. While this provides excellent bearing capacity, it can make excavation more difficult and costly. Engineers factor limestone presence into footing depth specifications.

Water Table Proximity

In suburbs close to the coast or Swan River (Fremantle, South Perth, Bassendean), the water table can be very high. Retaining walls may need additional waterproofing and drainage engineering.

Approval Requirements by Wall Type

Limestone Walls→Concrete Sleeper Walls→Timber Sleeper Walls→Concrete Block Walls→Gabion Walls→Rock Walls→

Related Guides & Resources

When You Need an Engineer→Choosing a Builder→Retaining Wall Cost Guide→Residential Services→

Council Approval FAQs

In Western Australia, retaining walls over 0.5 metres in height require a building permit from your local council. This is the lowest threshold in Australia. Walls under 0.5 metres may also require approval if they are near a boundary, support a surcharge load (like a driveway or structure), or are in a special control area.

You can generally build a retaining wall up to 0.5 metres (500mm) high without a building permit in Western Australia, provided it does not support any surcharge load, is not near a boundary where it could affect neighbouring properties, and complies with the Building Code of Australia. Always check with your local council as requirements can vary.

In Western Australia, a registered builder is required for building work valued at more than $20,000. For work between $7,500 and $20,000, a registered building service contractor is required. The WA Building Commission oversees registration. Since many retaining wall projects exceed these thresholds, you will typically need a registered contractor.

Building permit fees for retaining walls in Perth typically range from $300 to $1,000+ depending on the local council area and project complexity. This does not include the cost of engineering drawings ($500-$1,500) which are required as part of the application. Some councils also require planning approval for walls in heritage areas or near boundaries.

Building permit approval for a retaining wall in Perth typically takes 10-25 business days through a private building surveyor, or 20-35 business days through your local council. Using a private building surveyor (also called a certifier) is generally faster. You must not begin construction until the permit is issued.

Yes, in Western Australia you can use either a private registered building surveyor or your local council for building permit approval. Private surveyors are often faster (10-25 business days vs 20-35 for council) and may offer more flexible scheduling. Both options have the same legal standing under the Building Act 2011.

Building a retaining wall without a required building permit in Western Australia is illegal under the Building Act 2011 and can result in enforcement action, fines of up to $50,000, or an order to demolish the wall. Unapproved walls also create problems when selling your property, as building and compliance searches will reveal the non-compliance. Insurance may not cover damage from unapproved structures.

Need a Registered Builder Who Handles Approvals?

Many registered builders in our network can manage the entire approval process on your behalf — from engineering through to council certification.

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