Garden & terracing walls
Low walls that level a yard, create garden beds or step a slope into usable terraces. Usually the simplest engineering and the biggest visual change.
Sandstone retaining walls
Sandstone Block Retaining Walls — Hawkesbury & Hills District
A sloping block becomes usable land once it’s held back properly. We handle the excavation, the drainage and the sandstone, then pour what goes in front, so you get a finished area, not a to-do list.
- Licensed NSW concreting contractor
- Public liability & home warranty insured
- 13+ years on the tools
- ABN 55 852 128 340
How long does a sandstone retaining wall last?
Properly built, longer than almost anything else you can put in a garden — sandstone block walls are still standing on properties around the Hawkesbury a century after they went in. What kills a wall is never the stone. It is an undersized footing, no drainage behind it, or blocks set on fill that was never compacted.
- WhereHawkesbury, the Hills District and surrounding acreage
- WhatSandstone block walls, from garden terracing to large batter walls
- Who does itWe excavate, form the footing, drain it and place the blocks ourselves
- AlsoConcrete and core-filled block walls where sandstone is not the right answer
The complete package
What Goes Into A Sandstone Wall
Most of a retaining wall is invisible once it is finished. That is exactly why it is the job most often done badly — nobody can see what was skipped until the wall moves.
Levels and set-out
We survey the fall, work out the wall height and alignment, and check what the wall is actually holding back — soil, a driveway, a structure or a slope above it.
Excavation and batter
Our own machines cut the batter behind the wall line and strip back to firm ground. Spoil is removed or reused on site.
Footing
A compacted or concrete footing sized to the wall, sitting on undisturbed ground rather than on fill. This is the single biggest difference between a wall that lasts and one that leans.
Drainage
Ag line laid behind the wall in aggregate, wrapped in geotextile, with an outlet that actually goes somewhere. Water pressure behind a wall is what pushes it over.
Block placement
Blocks set with a machine, levelled, stepped and battered back into the slope. Faces dressed where the wall is on show.
Backfill and finish
Backfilled in layers with free-draining material, topped and tidied, and the surrounding ground graded so water runs where it should.
Types
Retaining Walls We Build
A garden terrace and a wall holding up a driveway on an acreage block are different engineering problems, even though both look like stacked stone.
Driveway & access walls
Walls holding up or holding back a driveway. These carry vehicle loads, which changes the footing and the drainage requirements completely.
Acreage batter walls
The big rural work. Long runs of large blocks cut into a slope to create a level building pad, shed site or house platform.
Shed & building pad walls
Where a pad has to be benched into a hill before anything can be built. We retain it, drain it and then pour the slab — see shed slabs.
Pool & entertaining walls
Walls that form the backdrop to a pool or outdoor area. Height and position here can affect pool barrier compliance, so the levels get checked first.
Concrete block walls
Where height, load or budget makes sandstone the wrong choice, we build core-filled or interlocking concrete block walls to the same standard.
Our standard
What We Build To
Two walls that look identical from the front can be completely different behind. Here is what is in a Southo wall as standard — if a cheaper quote does not mention these, it is not the same wall.
| Engineering | Walls retaining more than 600mm, or carrying a driveway, pool or building above them, are built to a structural engineer’s certification. We will tell you when your wall needs one. |
|---|---|
| On your quote | Footing, drainage, backfill and block spec written down before you accept, so you can compare like for like. |
Pricing
What Affects The Cost Of A Retaining Wall
Retaining wall quotes vary more wildly than any other concrete job, because there is so much a contractor can leave out and still produce something that looks finished on day one.
- HeightCost per metre climbs steeply with height. A wall twice as tall holds back far more than twice the load and needs a bigger footing to match.
- LengthTotal run of wall, and whether it is a straight line or steps, returns and curves.
- What it holds backGarden soil is one thing. A driveway, a pool or a building above the wall is another, and triggers engineering.
- Block size and typeLarger sandstone blocks cost more and need bigger machines, but go up faster and hold more.
- ExcavationHow much has to be cut out behind the wall, whether rock is hit, and where the spoil goes.
- Drainage and outletWhere the water behind the wall can actually discharge to. On flat or landlocked sites this can be the hardest part of the job.
- AccessWhether a machine can reach the wall line, or whether blocks have to be craned, walked in or placed from a distance.
- Engineering and approvalWalls over 600mm generally need certification and may need council approval, which adds cost and time.
Before you start
Approvals And Drainage Rules
Retaining walls are the concrete job most likely to get someone in trouble with a council or a neighbour. Two things are worth knowing before you commit.
The 600mm rule
Under the NSW Codes SEPP, support for earthworks more than 600mm above or below existing ground level must take the form of a retaining wall or structural support certified as structurally sound by a professional engineer.
Height is not the only condition. The exempt development standards also require the wall to sit a minimum distance from lot boundaries, to be separated from any other retaining wall, to have adequate drainage connected to stormwater, and to keep clear of easements, sewer and water mains. Heritage items, flood control lots and environmentally sensitive land are excluded entirely — which rules out a lot of the Hawkesbury floodplain.
We are concreters, not certifiers. Confirm your pathway with Hawkesbury City Council, The Hills Shire Council or a registered certifier before the first machine arrives.
Source: NSW State Environmental Planning Policy (Exempt and Complying Development Codes) 2008 — earthworks, retaining walls and structural support provisions. Checked 15 September 2026.
Water is the neighbour problem
The exempt development standards specifically require that earthworks and retaining walls must not redirect the flow of surface water or ground water, or transport sediment, onto an adjoining property.
This matters more than people expect. A wall that terraces your yard nicely can concentrate runoff and send it straight into next door’s shed. It is one of the most common sources of neighbour disputes on sloping blocks, and it is entirely avoidable at the design stage.
Every wall we build gets a drainage line with a real outlet, and the surrounding ground graded so water goes where it is supposed to.
Source: NSW State Environmental Planning Policy (Exempt and Complying Development Codes) 2008; design and construction of earth-retaining structures is covered by AS 4678 Earth-retaining structures. Checked 15 September 2026.
Recent work
Retaining Walls We’ve Built
Why Southo
Why Owners Use Us For Retaining Walls
We dig it ourselves
The excavation, the footing and the wall are one contractor’s job. Nobody to blame if the ground behind it was never right.
Drainage is not an extra
Ag line, aggregate and an outlet are in every wall we build. It is the first thing a cheap quote leaves out.
Machines that reach
Acreage walls a long way from the road, on slopes, with no hardstand. Our own plant means we can get the blocks where they need to go.
We say when you need an engineer
If your wall needs certification we will tell you at the quote, not after it is built and a certifier knocks it back.
Licensed and insured
Licensed NSW concreting contractor with public liability and home warranty insurance. Details supplied on request.
It still looks right
Faces dressed, courses level, stepping and batter consistent. A structural wall that also reads as landscaping.
Got a slope. Need it held.
Send us a photo of the slope and rough measurements and we’ll tell you what it needs.
Reviews
Our Customer Reviews
Service area
Where We Build Retaining Walls
Based in the Hawkesbury, working across the Hills, Sydney and the Central Coast.
Questions
Retaining Wall FAQs
Do I need council approval for a retaining wall?
It depends on height, position and what the wall supports. Under the NSW Codes SEPP, earthworks support over 600mm above or below existing ground level requires an engineer-certified wall, and the exempt development standards add conditions on boundary setbacks, drainage, easements and land type. Confirm your pathway with your council or a registered certifier before you start.
Sandstone or concrete block — which should I use?
Sandstone looks better and suits acreage and garden settings, and large blocks handle real height. Core-filled concrete block is often the better answer for tall walls, tight spaces, or where the wall will be hidden anyway. We will tell you which one fits your site rather than pushing one.
Why do retaining wall quotes vary so much?
Because most of the cost is buried. Footing depth, drainage, backfill material and compaction are invisible once the wall is finished, so they are the first things a cheap quote drops. Ask every quote to list them and the range narrows fast.
Can you build a wall on a boundary?
Sometimes, but it is the most constrained situation there is — setback rules, the neighbour’s ground, drainage, and often engineering all come into play. We will look at it and tell you honestly whether it works.
Will the wall affect my neighbour?
It can, and that is worth getting right. The rules require that a wall does not redirect surface or ground water or push sediment onto an adjoining property. We design the drainage and finished levels so runoff goes where it should.
Do you do the landscaping as well?
We do the structural work — excavation, wall, drainage and backfill — plus any concrete that goes with it. Planting and soft landscaping we leave to a landscaper, and we are happy to work in alongside one.
How long does a wall take to build?
A small garden wall can be a couple of days. A long acreage batter wall with significant excavation runs into weeks. We give you a realistic window at the quote, and we do not start a job we cannot finish.
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Accuracy note
Planning and engineering information on this page is general and was correct at the date checked against the sources named above. Rules change and every site is different — confirm your own situation with Hawkesbury City Council, The Hills Shire Council or a registered certifier. Spotted something out of date? Email southoconcrete2@outlook.com.
