Retaining Wall Regulations in Perth: Council Rules & Approval Guide
If you’re planning to build a retaining wall in Perth, it’s important to understand that it’s not just a landscaping feature—it’s a structure governed by local regulations. Whether you’re looking to prevent soil erosion, level a sloped backyard, or create more usable space, you must ensure your retaining wall complies with council requirements and building codes in Western Australia.
In this article, we’ll break down the key retaining wall regulations for Perth homeowners and property developers. You’ll learn when approvals are needed, what height limits apply, who is responsible for the wall, and how to avoid costly mistakes.
Why Retaining Wall Regulations Exist
Retaining walls, especially those over a certain height, can pose structural and safety risks if not built correctly. Local councils enforce regulations to:
- Prevent structural failure that could damage property
- Ensure proper drainage and water runoff
- Avoid disputes between neighbours
- Maintain aesthetic standards in residential zones
- Protect underground services and boundaries
Ignoring these rules could result in forced demolition, fines, or liability for property damage.
Do You Need Council Approval for a Retaining Wall in Perth?
The general rule across Perth councils is:
If your retaining wall is higher than 500mm (0.5 metres), you will need council approval.
However, there are other conditions that may trigger the need for approval, even if the wall is under 500mm. These include:
- The wall is located within 1 metre of a boundary
- It is part of a larger landscaping or building project
- It may affect natural water flow or stormwater management
- It supports a load like a driveway, fence, or structure
- It is built on slope-prone or reactive soil (e.g., hills or coastal areas)
Tip: Always contact your local council before beginning work. Requirements can vary slightly between councils such as the City of Joondalup, City of Stirling, or City of Wanneroo.
Retaining Wall Height Limits (Without Approval)
| Wall Height | Approval Required? | Notes |
|---|---|---|
| 0–499mm | No (if not near boundary) | Must not alter natural ground level significantly |
| 500mm–999mm | Yes | Engineering drawings may be required |
| 1m+ | Yes | Must comply with the Building Code of Australia (BCA) |
Important: The height is usually measured from the base of the retained soil, not the visible height above ground.
Who Is Responsible for the Retaining Wall?
Responsibility often depends on who benefits from the wall:
- If the wall is retaining land for your benefit (e.g., to level your backyard), then you are responsible.
- Shared boundaries can be more complex. If both neighbours benefit, cost-sharing may be arranged—but this must be agreed upon in writing.
What you should do:
- Check property title plans for boundaries
- Have a conversation with your neighbour before construction begins
- Avoid placing walls directly on boundary lines without legal advice
Engineering Requirements for Retaining Walls
If your wall exceeds 500mm or supports a significant load, you may need:
- Structural drawings from a licensed engineer
- Certification documents
- A site inspection and soil report
An engineer ensures the wall:
- Has adequate footing depth for Perth’s sandy or clay soils
- Is properly drained (ag pipes, gravel layers, weep holes)
- Won’t impact surrounding structures or boundaries
Drainage Requirements
One of the most common reasons for retaining wall failure in Perth is poor drainage.
Your wall should include:
- Ag drain pipe behind the base
- Free-draining gravel behind the wall
- Weep holes at regular intervals
- Waterproofing membrane in some cases
Note: If poor drainage causes water to overflow into a neighbour’s yard, you may be held liable for property damage—even if your wall is technically legal.
Building Near Boundaries and Neighbours
If your wall is within 1 metre of a boundary, the council may require:
- Setback distances
- Written consent from neighbours
- Additional safety measures if the wall is visible from the street
In some cases, fencing on top of a retaining wall may require a combined retaining wall + fencing approval.
Common Mistakes to Avoid
- Assuming council approval isn’t needed for low walls
- Building without engineering on sloped or soft soil
- Skipping drainage or using incorrect materials
- Placing the wall directly on the boundary without confirming the legal boundary line
- Ignoring neighbours when walls may impact their property
Local Council Resources (Perth)
Here are helpful links for retaining wall guidelines:
- City of Stirling – Retaining Walls
- City of Joondalup – Building Guidelines
- City of Wanneroo – Development Info
- City of Vincent – Building Retaining Walls
When to Contact a Professional
Contact a professional contractor if your wall is:
- Taller than 500mm
- Built near a boundary
- Located on a slope
- Supporting a fence, pool, or driveway
A licensed retaining wall builder will handle:
- Council submissions
- Engineering and structural calculations
- Site prep, drainage, and installation
Final Thoughts
Complying with retaining wall regulations in Perth isn’t just red tape—it’s protection for your investment and peace of mind. With the right planning and guidance, your retaining wall will be strong, safe, and long-lasting.
Need Help Navigating Council Rules?
Perth Retaining Wall Pros has years of experience building compliant, high-quality retaining walls across WA. We handle everything from design and permits to construction.
Contact us today for a free site inspection and expert advice tailored to your property.