Soil test cost by state: QLD, NSW, VIC, SA and WA

A residential soil test, meaning an AS 2870 site classification with a small number of boreholes, starts at about $700 across most of the country in 2026, runs $1,200 to $2,500 with footing design, and moves past $3,000 once a full investigation with laboratory testing is needed. The base price does not vary much between capital cities. What varies is how often a block needs more than the base scope, and that is set by the ground and the distance to the block.

This covers what pushes the price up in Queensland, New South Wales, Victoria, South Australia and Western Australia, so a quote can be judged against the state it was written in. For the national tiers by report type, see the geotechnical report cost guide.

Why the base price is similar and the final price is not

Three things sit in every quote: travel to the block, time on the hole, and whether the classification can be settled by identifying the profile or has to be measured in a laboratory. The first is geography. The second and third are geology and climate, and they are the reason two blocks 40 km apart in the same state attract different scopes.

The state sections below are about what commonly triggers the extra scope. Why the class letters themselves differ between cities is a separate question, covered in why the same clay classifies differently in Sydney, Melbourne and Adelaide.

State	What most often adds cost	What that means for the quote
QLD	Reactive clays inland and on the Darling Downs, soft coastal lowland deposits, acid sulfate soils, long travel outside the south-east	Laboratory testing more often, deeper holes on coastal fill estates
NSW	Which rock the lot sits on, shale against sandstone, plus rock refusal and steep sites	Shallow rock can end a hole early and force another; excavation risk moves to the builder
VIC	Basaltic clays west and north of Melbourne, and a climate that has been trending drier	Measured shrink-swell testing rather than profile identification
SA	Highly expansive metropolitan clays with deep seasonal drying	Deeper holes and testing, heavier footing design
WA	Dune sands and limestone on the Swan Coastal Plain, clays through the Darling Range	Fewer reactive-clay questions, more density, cavity and groundwater questions

Queensland

Base pricing applies across Brisbane, Logan, Ipswich, the Gold Coast and the Sunshine Coast, where borehole coverage is dense, the geology is well mapped and mobilisation is short. Costs rise on three fronts: the basalt-derived clays around Toowoomba and the Darling Downs, which are frequently reactive enough that a laboratory shrink-swell test settles the class rather than an identification; the coastal lowland estates, where soft compressible deposits, shallow groundwater and acid sulfate soils turn a two-hole classification into a deeper investigation; and regional travel, which dominates a quote outside the south-east. Fox (2002) mapped the Thornthwaite Moisture Index across Queensland, which is what sets the design drying depth used in the classification and part of why inland results sit higher than coastal ones. The detail is in soil test cost in Queensland.

New South Wales

Sydney quotes sit at or slightly above the Queensland figures, driven by travel time across the basin and rig availability rather than a different scope. The ground question in Sydney is which rock the lot is on: the shale country through the western growth corridors weathers to reactive clay, the sandstone suburbs are often benign, and the Newcastle coal measures are more reactive again. Chan and Mostyn (2009) mapped climate factors across 64 NSW weather stations so the zone for a lot can be read from a published map before anyone visits.

Two things add cost in NSW more than elsewhere. Shallow rock ends a borehole early, which can mean another hole, and it moves the risk to the excavation budget rather than the footing budget. Steep sites through the northern beaches, the Illawarra and the Blue Mountains often cannot take a truck-mounted rig, so the work is done by hand auger or a tracked rig at a higher rate.

Victoria

The base classification price in Melbourne is comparable to Brisbane and Sydney. What lifts the average is the basaltic clay of the Newer Volcanics west and north of the city. Li et al. (2016) tested 47 sites across 37 Melbourne suburbs and found shrink-swell indices above 6 percent strain per pF common in the west and north, with the Newer Volcanics alone ranging from about 1.1 to 11, and large scatter inside a single mapped unit. Scatter of that size is the argument for measuring the index rather than identifying the profile, so laboratory work appears in Melbourne quotes more often than in the sandstone suburbs of Sydney.

South Australia

Adelaide is the case where the ground, not the travel, sets the price. The Keswick and Hindmarsh clays under much of the metropolitan area are highly expansive, and the climate is semi-arid, so seasonal drying reaches deep. Jewell and Mitchell (2009) measured how strongly vegetation and ground cover changed seasonal movement at reactive sites near the city. Practically, more Adelaide blocks need holes deeper than a standard suburban two, more need laboratory testing, and more end in a class that carries a heavier footing design fee. Regional South Australia is a travel story again, with the Adelaide Hills adding access constraints on top.

Western Australia

Much of the Swan Coastal Plain is dune sand: the Bassendean, Spearwood and Quindalup systems described by Wyrwoll (2003), with Tamala Limestone beneath parts of the coastal strip. Sand is not reactive, so the expensive question in Perth is usually not clay movement. It is density and compaction, cavities and dissolution features in the limestone, and shallow groundwater, all of which are investigation questions rather than classification questions. Through the Darling Range the profile changes to clays and weathered granite, and the classification question returns.

What to do with a quote before you accept it

1. Check the scope against the state's usual triggers. A Melbourne quote with no laboratory allowance on basalt clay, or a coastal Queensland quote scoped as a standard two-hole suburban job, is worth a question.
2. Ask what happens on refusal. In shale, sandstone and limestone country, the answer decides whether a second visit gets billed.
3. Group lots into one mobilisation where more than one block is being tested. Travel is the line item that does not scale with hole count.
4. Screen the block first. Mapped geology, terrain, nearby borehole logs, groundwater records and hazard mapping are all available before the rig is booked, and they are what tells you which of the triggers above applies to your lot.

No desktop assessment, ours included, produces the classification a certifier will accept. AS 2870 requires site-specific investigation, and the letter has to come from an engineer who has seen the profile. The desktop work sets the scope; the fieldwork settles it.

Common questions

How much does a soil test cost in Australia?

From about $700 for a standard AS 2870 site classification with two boreholes in 2026, $1,200 to $2,500 with footing design, and from about $3,000 for a full investigation with laboratory testing. The base price is similar across the capital cities; the state differences show up in how often a block needs more than the base scope.

How much does a geotechnical report cost in Sydney?

Sydney sits at or slightly above the Queensland figures for the same scope, driven by travel and rig availability. The larger variable is the ground: a sandstone lot may need nothing beyond the standard scope, while a shale lot in the western growth corridors or a steep site that cannot take a truck-mounted rig will cost more.

Why is a soil test more expensive in Adelaide than Brisbane?

Not because the hourly rates differ. Adelaide's metropolitan clays are highly expansive and the semi-arid climate dries the ground deeply, so more blocks need deeper holes, laboratory testing and a specifically designed footing system than a typical suburban Brisbane lot does.

Does the soil test price change between states?

Not by much for the same scope. The published price tiers are close across the capitals. What differs is how often the standard scope is enough, which is set by local geology, climate and how far the rig has to travel.

To see which of these triggers applies to a specific block before you request quotes, generate a desktop report for the address, or see a sample report.

LayeredGeo compiles geology, soils, groundwater and site data into an automated geotechnical desktop report for any address in Queensland, New South Wales or Victoria.

Sources

• Chan, I. and Mostyn, G. (2009). Climatic factors for AS2870 for New South Wales. Australian Geomechanics, Vol 44 No 2. geomechanics.org.au
• Fox, E. (2002). Development of a map of Thornthwaite Moisture Index isopleths for Queensland. Australian Geomechanics, Vol 37 No 3. geomechanics.org.au
• Jewell, S. A. and Mitchell, P. W. (2009). The Thornthwaite Moisture Index and seasonal soil movement in Adelaide. Australian Geomechanics, Vol 44 No 1. geomechanics.org.au
• Li, J., Zou, J., Bayetto, P. and Barker, N. (2016). Shrink-swell index database for Melbourne. Australian Geomechanics, Vol 51 No 3. geomechanics.org.au
• Wyrwoll, K-H. (2003). The geomorphology of the Perth region, Western Australia. Australian Geomechanics, Vol 38 No 3. geomechanics.org.au

About this article. Published by LayeredGeo and written from the published research cited in the Sources section above. It is general information about how property and ground conditions are assessed in Australia, not engineering, planning, legal or financial advice, and it is not specific to any property. Check anything that matters against the source dataset or a suitably qualified professional before you rely on it. If you spot something wrong, tell us at hello@layeredgeo.com.au and we will fix it.

← All articles