The price of a retaining wall comes down to how high it is, what it is built from, what is in the ground and how easy it is to get machinery and materials onto your block. Across the Blue Mountains and Penrith, our retaining walls start from $900 per square metre of wall face, installed, for Keystone concrete block and sleeper walls, and from $1,000 to $1,300 per square metre for sandstone and ironstone. All prices in this guide exclude GST.
This guide sets out what we charge for each material, what pushes the price up or down on a real site, and when your wall will need council approval. The figures come from walls we have built across the Blue Mountains, Penrith and the Central West rather than national averages.
Prices last reviewed October 2026.
Retaining wall cost at a glance
These are our starting prices per square metre of wall face, installed and excluding GST. To work out the area of your wall, multiply its length by its height, so a wall 10 metres long and 1 metre high is 10 square metres.
Each rate is all inclusive and covers the job from excavation through to completion. The final price depends on access to your block, as well as the wall’s height, what is in the ground and drainage, so treat these as starting points.
| Wall type | Installed price per m2 (excl. GST) | Where it suits |
|---|---|---|
| Keystone concrete block | From $900 | Straight, even walls for gardens, driveways and boundaries |
| Hardwood sleepers | From $900 | Lower garden walls away from the house |
| Concrete sleepers | From $900 | Straight garden and boundary walls |
| Sandstone logs (B grade) | From $1,000 | Larger walls on open sites and natural bushland settings |
| Sandstone ballast | From $1,100 | A rougher, textured stone face for garden and boundary walls |
| Ironstone | From $1,300 | Lower garden walls with a rustic look |
What affects the cost of your retaining wall
Two walls of the same size can be priced very differently. These are the factors that make the difference on Blue Mountains and Penrith blocks.
Wall height
Height has the biggest effect on price. A taller wall holds back more soil, so it needs deeper footings, more material per metre and better drainage behind it.
Once your wall is higher than 600mm, or sits within a metre of your boundary, it will usually need council approval and an engineer’s design as well, which we explain in the council section below.
The material you choose
Sandstone, concrete block, ironstone and sleepers all sit at different price points, from $900 per square metre for Keystone concrete block and sleepers up to $1,300 for ironstone. The cheapest material per square metre is not always the cheapest wall, though. On larger walls with good access, B grade sandstone logs can work out more affordable than block overall, because each log covers a lot of wall face and goes in quickly with an excavator.
If you are leaning towards sandstone, our guide to the benefits and uses of sandstone retaining walls covers where it works best.
Rock and excavation
Much of the Blue Mountains sits on sandstone, so hitting rock when digging footings or cutting into a slope is common. Rock has to be hammered or broken out before your wall can go in, which adds machine time to the job, and the soil and rock that come out have to be trucked away.
We carry out our own excavation and rock removal, so the digging, the footings and the wall are all handled by the same team.
Access to your block
The size of machine that can reach your wall makes a big difference to cost. On an open block, a larger excavator can place heavy sandstone logs quickly, while a steep driveway or narrow side access means smaller machines, more trips and more handwork.
At Tennyson Cottage, a narrow road and tight access close to the house meant using 5 tonne and 1.7 tonne excavators and bringing in only a few sandstone logs at a time. The project took about three weeks.
Drainage behind the wall
Every retaining wall needs a way for water to get out from behind it. That usually means a slotted ag pipe at the base, clean gravel backfill and geofabric to stop soil clogging the gravel.
Drainage is part of every wall we build, and it is what keeps water pressure off your wall on sloping blocks that take heavy rain.
Bushfire-prone blocks
If your block is bushfire-prone, it is worth considering stone or concrete over timber for walls close to the house, since they do not burn. That can change which material fits your budget.
Where your property is
We build retaining walls across the Blue Mountains, Penrith and the Central West, including Lithgow, Bathurst, Orange and Oberon. For jobs in the Central West, a travel fee is added to the quote. Every quote is based on your site, so the best first step is a site inspection.
Which retaining wall material suits your block
Sandstone logs and ballast
Sandstone suits the Blue Mountains landscape and it is our speciality. Large B grade sandstone logs, from $1,000 per square metre, suit bigger walls on open sites. Sandstone ballast, from $1,100 per square metre, uses rougher quarry-cut blocks in random, squarish shapes, which gives the wall a more textured, natural face.
Keystone concrete block
Keystone is a modular concrete block system that interlocks as it is laid, giving a straight, even wall with a clean, modern finish. From $900 per square metre, it suits garden walls, driveways and boundaries, and taller walls are built to an engineer’s design.
Ironstone
From $1,300 per square metre, ironstone gives a rustic, textured look and works well for lower garden walls and garden bed edges.
Hardwood sleepers
Hardwood sleepers start from $900 per square metre and suit shorter garden walls away from the house. On bushfire-prone blocks, stone or concrete is the better choice close to the house.
Concrete sleepers
Concrete sleepers also start from $900 per square metre. They suit straight garden and boundary walls, and unlike timber they will not burn or rot.
What a 10 metre retaining wall costs
A wall 10 metres long and 1 metre high is 10 square metres of wall face. At our starting prices, excluding GST, that wall would start from around:
- $9,000 in Keystone concrete block, hardwood sleepers or concrete sleepers
- $10,000 in sandstone logs
- $11,000 in sandstone ballast
- $13,000 in ironstone
Those figures assume an open block with good access. The same wall on a steep block with tight access and rock in the footings will cost more, mostly because of the extra machine time and handwork, which is why we look at your site before giving a firm price.
Do you need council approval for a retaining wall in NSW?
In NSW, a small retaining wall can be built without council approval as exempt development if it meets the state rules. Among them, your wall must be no higher than 600mm above existing ground level, at least one metre from any boundary, at least two metres from any other retaining wall on the site and at least 40 metres from a natural body of water.
It also must not redirect surface water or groundwater onto a neighbouring property, must be structurally adequate and must not be built on a heritage item. The full list is on the NSW Planning Portal.
A wall outside those limits needs approval, through either a complying development certificate or a development application, and usually an engineer’s design. We can talk you through whether your wall is likely to need approval when we look at your site.
How to keep your retaining wall cost down
- Price the whole job together. If you also need excavation, drainage, a driveway or paving, having one team do it all avoids paying for machinery to come back twice.
- Choose the material for your site, not just the price per square metre. On a larger wall with good access, sandstone logs can come in under block.
- Where your levels allow, two lower walls stepped at least two metres apart can sometimes avoid the approval and engineering costs of one tall wall.
How we price your retaining wall
01. Tell us about your wall. Let us know where it is going and roughly how long and high it needs to be. If you have plans or photos, send them through.
02. We inspect your site. We visit your block to check the height, soil, rock, drainage and access.
03. You get your quote. We give you a price and talk you through the material options, including any approvals your wall may need.
04. We build it. Our team handles the excavation, footings, drainage and retaining wall construction, and leaves your site tidy.
For builders, developers and councils, we can price retaining walls from plans and drawings. See our commercial sandstone walls for larger projects.
Retaining wall cost FAQs
How much does a retaining wall cost per square metre?
Our retaining walls start from $900 per square metre of wall face, installed, for Keystone concrete block, hardwood sleepers and concrete sleepers. Sandstone logs start from $1,000, sandstone ballast from $1,100 and ironstone from $1,300 per square metre. All prices exclude GST and cover the job from excavation through to completion. Height, rock, access and drainage move the final price up from these starting points.
Is sandstone more expensive than concrete block?
Not always. Sandstone logs start from $1,000 per square metre, compared with $900 for Keystone concrete block. On larger walls with good access, though, B grade sandstone logs can work out more affordable overall, because each log covers a lot of wall face and goes in quickly.
Do I need council approval for a retaining wall?
Not if your wall meets the NSW exempt development rules, which include being no higher than 600mm above existing ground and at least one metre from any boundary. A taller wall, or one closer to the boundary, needs approval and usually an engineer’s design.
What should a retaining wall quote include?
A complete quote should cover excavation, spoil removal, footings, drainage, backfill and the wall itself, plus any engineering or approvals. If a quote leaves any of these out, ask whether they are extra. Our rates are all inclusive from excavation through to the finished wall, with the final price depending on access to your site.
How long does it take to build a retaining wall?
It depends on the size of your wall, the access and what is in the ground. As an example, the sandstone retaining walls at Tennyson Cottage, on a tight site close to the house, took about three weeks.
Ready to price your retaining wall?
Book a free site inspection and quote, and we will look at your block, talk you through the materials and give you a clear price. One team handles your excavation, drainage and wall construction, backed by ISO 9001, 14001 and 45001 certification.
Call Andrew on 0435 355 975 or book a free site inspection and quote.
