Types of Retaining Walls

Retaining walls stabilise sloped land by holding back soil and controlling erosion. In Australian construction, they are used in residential, commercial, and civil projects to create level surfaces, protect structures, and manage drainage. A retaining wall increases land usability and protects against soil movement during rainfall or excavation.

There are 9 main types of retaining walls, each defined by structure, materials, and application. These include gravity walls, cantilever walls, anchored walls, and sheet pile systems, as well as modern solutions like reinforced soil walls, gabions, and crib systems. Some walls rely on mass, others on reinforcement or anchoring.

This guide explains each type of retaining wall with clear definitions, real-world examples, and core structural differences. If you're planning a build or want to understand walling systems better, this article will give you the essential foundation.

What Is a Retaining Wall?

A retaining wall is a structure built to hold back soil and prevent it from shifting or eroding. It creates stable, level ground on sloped terrain and supports vertical or near-vertical grade changes. Retaining walls are used across Australia in landscaping, roadworks, and structural projects to manage gravity, water flow, and lateral earth pressure.

We'll explore this topic in detail in our next guide on what is a retaining wall.

Why Retaining Walls Matter in Australian Construction?

Retaining walls are essential in Australian construction due to the country’s diverse topography, soil conditions, and weather extremes. They protect properties built on sloped land, support elevated driveways, and prevent soil displacement caused by heavy rainfall or bushfire runoff.

In urban developments, they maximise land use by allowing safe levelling for building pads and garden terraces. On rural or coastal blocks, retaining walls reduce erosion and control surface water. By meeting structural and regulatory requirements, they ensure long-term site stability and safety across residential and commercial projects.

Murs Projects delivers wall systems tailored to Australian conditions, securing safe, durable, and regulation-ready outcomes for residential and commercial developments.

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What are the Types of Retaining Walls?

There are several types of retaining walls, each engineered to resist soil pressure using different structural methods. Some rely on mass and gravity, while others use reinforcement, anchoring, or interlocking systems. The choice depends on site conditions, load demands, and intended use.

Below are the most common types of retaining walls used in Australia:

1. Gravity Retaining Wall

A gravity retaining wall resists soil pressure using its own weight. It is constructed from heavy materials like concrete blocks, stone, or brick, which create stability without needing internal reinforcement. The wide base and backward-leaning face help distribute pressure evenly and prevent tipping.

This wall type is ideal for low-height applications, typically under 1 metre, such as garden edging or residential landscaping. It suits stable soil conditions and can often be installed without formal engineering approval, making it a cost-effective solution for small-scale Australian projects.

However, proper drainage behind the wall, such as gravel fill and weep holes is essential to avoid water pressure build-up.

2. Cantilever Retaining Wall

A cantilever retaining wall uses a reinforced concrete base and vertical stem to counter soil pressure through leverage. The horizontal slab extends beneath the retained soil, allowing the weight of the soil above to stabilise the structure. This method creates strength without excessive wall thickness.

Cantilever walls are common across Australian developments where wall height ranges from 1 to 5 metres. They’re often used along driveways, boundary edges, or terraced blocks.

Proper engineering is essential to comply with AS 4678, and effective drainage is needed to reduce hydrostatic pressure behind the wall.

3. Anchored Retaining Wall

Anchored retaining walls use steel rods or cables that extend deep into the ground behind the wall and are tensioned to secure the structure. These anchors provide additional support, allowing thinner wall profiles to hold back high volumes of soil or water.

This system is ideal for tall walls or limited-space environments where external reinforcement is impractical. It’s commonly used in large-scale civil projects or steep excavations across urban sites in Australia.

Anchored walls require detailed geotechnical design to ensure the anchors hold under variable loads.

4. Sheet Pile Retaining Wall

Sheet pile walls consist of vertical sheets—usually made from steel, timber, or vinyl—driven into the ground to form a continuous barrier. They are designed to resist horizontal soil or water pressure and are often supported by anchors or tiebacks.

These walls are effective in areas with soft soils, coastal sites, or narrow access zones. In Australia, they’re commonly used in marine works, temporary excavations, or urban settings with limited space.

Their quick installation and minimal footprint make them suitable for both temporary and permanent use.

5. Reinforced Soil Retaining Wall (MSE Wall)

A reinforced soil wall, or Mechanically Stabilised Earth (MSE) wall, combines compacted soil with horizontal layers of reinforcement such as geogrid or steel strips - anchored behind a facing system. The facing can be modular blocks, panels, or even vegetated surfaces.

MSE walls are highly flexible, cost-efficient, and can reach substantial heights. They are widely used in road construction, retaining long embankments, and commercial landscaping throughout Australia.

Their modular nature allows creative shaping and integration with green spaces.

6. Crib Retaining Wall

Crib walls are formed from interlocking concrete or timber units arranged like a grid and filled with crushed rock. The open-cell design provides mass and natural drainage, which enhances wall stability while reducing hydrostatic pressure.

They’re often seen in gardens, parks, and light civil works. Timber crib walls suit low-load areas, while concrete versions can handle higher structural demands.

Their modular layout allows curved or stepped installations on undulating terrain.

7. Gabion Retaining Wall

Gabion walls consist of wire mesh cages filled with rock or rubble. Their mass resists soil pressure, while the porous structure allows free drainage, reducing water-related damage and soil pressure build-up.

These walls are commonly used in coastal areas, bushland, or erosion-prone slopes. Their flexibility makes them ideal for uneven terrain, and their rugged appearance suits natural or rural aesthetics.

Gabion walls also perform well in areas prone to ground movement or flooding.

8. Bored Pile Retaining Wall

Bored pile walls are constructed by drilling deep cylindrical holes into the ground, inserting steel reinforcement, and filling them with concrete. The piles can be installed side-by-side or spaced with infill panels depending on the load and soil conditions.

These walls are frequently used in urban Australian sites where space is tight, and vibration must be minimised. They’re effective for deep excavations, basement support, or high-rise foundation work.

Their strength and durability make them a go-to for heavy infrastructure projects.

9. Timber Retaining Wall

Timber retaining walls use treated hardwood or pine sleepers arranged horizontally and secured with steel posts or timber uprights. They are simple to build and provide functional support for low-height soil retention.

Common in residential landscaping, timber walls are cost-effective and blend well with natural surroundings. While timber has a shorter lifespan than concrete or stone, proper treatment and drainage can extend durability up to 20 years in Australian conditions.

10. Green (Living) Retaining Wall

Green retaining walls combine structural support with vegetation, using geogrid-stabilised soil bags, planter boxes, or vertical planting systems. These designs allow for root growth, soil containment, and wall reinforcement.

They’re growing in popularity in urban landscapes and sustainable developments across Australia. While their primary appeal is aesthetic and environmental, green walls also reduce surface runoff, absorb heat, and promote biodiversity when designed correctly.

How to Choose the Right Retaining Wall Type

Choosing the right retaining wall depends on the site’s physical conditions and what the wall needs to achieve. Soil type, wall height, load-bearing requirements, and local council rules all influence which structure is best suited.

Each retaining wall type functions differently, so matching the wall to the conditions is essential for long-term performance and compliance.

For example,

• Gravity walls are ideal for low-height landscaping where space isn’t a constraint.

• Cantilever walls suit residential blocks with moderate slopes.

• Reinforced soil and crib walls perform well for wide embankments, while bored pile and anchored walls are better for large loads or limited access sites.

• In bushfire zones or coastal areas, selecting materials with high durability—like concrete or steel is critical. Always check whether your wall needs engineering certification under AS 4678 or approval from your local council.

Regulations, Standards & Design Life

In Australia, retaining walls must meet structural, drainage, and safety requirements set by local councils and national standards. The most relevant code is AS 4678 – Earth-retaining structures, which governs design criteria for walls over 800 mm in height. Additionally, the National Construction Code (NCC) and individual state regulations apply, especially when walls are load-bearing, near property boundaries, or part of a larger development.

Wall design life depends on material, exposure, and engineering quality. Concrete and steel structures often exceed 50–60 years with proper drainage and soil management. Timber walls, when constructed with treated hardwood and installed correctly, last up to 20 years. Councils in NSW, VIC, and QLD generally require formal approval for any wall above 600 mm to 1 m, depending on location. Check permit requirements before construction to achieve compliance and long-term structural integrity.

We'll help you navigate council approvals, meet all design standards, and build a retaining wall that stands the test of time. Give us a call us at 0420 203 076.

Frequently Asked Questions

What type of retaining wall lasts the longest?

Reinforced concrete, bored pile, and anchored retaining walls have the longest lifespan, often exceeding 50 years with proper drainage and design.

Can I build a timber retaining wall myself?

Yes. Treated timber sleeper walls under 1 m can often be built without a contractor, but it’s important to follow drainage and bracing requirements for safety.

Which retaining wall is best for sloped blocks?

Cantilever and reinforced soil walls work well on sloped blocks, as they provide strong structural support and can be adapted to variable site conditions.

What is the cheapest type of retaining wall?

Timber sleeper and unreinforced gravity block walls are typically the cheapest to build, especially for small, non-load-bearing landscaping applications.