How much does a soil test cost? 2026 prices by state

A soil test for a house costs from about $700 in 2026 for a standard AS 2870 site classification with two boreholes on a suburban lot. Adding footing design takes it to roughly $1,200 to $2,500, a full investigation with laboratory testing starts around $3,000, and complex or disputed sites run higher. An automated desktop report is $119, but it scopes the job; it is not a classification.

The base price barely moves between Brisbane, Sydney, Melbourne and Adelaide. The minimum job does. Ground and climate set the scope, travel sets the rest, and that is what separates a quote in one state from a quote in another.

How much does a soil test cost?

What you commission	Indicative cost	Turnaround
Automated desktop report	$119	Minutes
Desktop assessment by a consultant	$800 to $1,200	1 to 2 weeks
Site classification, 2 boreholes	from $700	1 to 3 weeks
Site classification with footing design	$1,200 to $2,500	2 to 4 weeks
Full investigation, drilling and laboratory	$3,000+	3 to 6 weeks
Complex, disputed or large sites	$3,000 to $10,000+	Varies

The "soil test" is the site classification: someone drills the lot, logs the soil and assigns the class (A, S, M, H1, H2, E or P) the slab is designed to. AS 2870-2011 asks for at least one hole per building site, to at least 0.75 times Hs (the depth to which the soil wets and dries with the seasons) and never shallower than 1.5 m unless it hits rock. Hs is 1.5 to 2.3 m for Brisbane and Ipswich, 1.5 to 1.8 m for Sydney and 4.0 m for Adelaide, so the minimum job differs a lot between cities. Most firms drill two holes on a suburban lot. What a full geotechnical report adds, and what each line in a quote pays for, is in the geotechnical report cost guide.

What adds cost in each state?

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	At least three holes to at least 3 m in Adelaide under AS 2870, more 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

Two blocks 40 km apart in the same state can attract different scopes for the same reasons. Why the class letters themselves differ between cities is covered in why the same clay classifies differently in Sydney, Melbourne and Adelaide.

Soil test cost in Queensland and Brisbane

Base pricing applies across Brisbane, Logan, Ipswich, the Gold Coast and the Sunshine Coast, where the geology is well mapped and travel is short: from about $700 for a two-hole classification on a suburban lot. With Hs of 1.5 to 2.3 m for Brisbane and Ipswich and 1.8 to 2.3 m for Toowoomba, the minimum hole on most Queensland lots is about 1.5 to 1.7 m. What differs is how often a lot needs more than the base job, and the reasons are usually visible before anyone drills.

Why is laboratory testing an extra on a Queensland quote?

Because South East Queensland has long classified sites without it. Bruce Hargreaves, a Brisbane geotechnical engineer, kept more than 300 site classification reports from eleven consultants dated 1999 to 2001. Those firms did well over 80 percent of the region's classifications for project builders and owners, and only one of them ran a shrink-swell test (Iss, the lab measure of how much a clay swells and shrinks with moisture). The rest identified the soil profile and relied on experience of how it performs (Hargreaves 2005).

AS 2870 still allows that, and it is what the base price assumes. When the profile cannot be settled by identification, samples go to the lab and the testing goes on the quote. Expect that more often on the basalt clays around Toowoomba and the Darling Downs, which frequently come back at the H and E end. Fox (2002) mapped the climate index that sets drying depth across Queensland from weather records averaging 88 years, and showed how far short records can mislead.

What else pushes a Queensland quote up?

Fill, and the paperwork for it. Under AS 2870-2011, uncontrolled fill makes a site Class P unless every footing goes through it to natural soil, and controlled fill other than sand deeper than 0.4 m is Class P unless an engineer reclassifies it. "Controlled" means placed and tested to AS 3798, the earthworks standard. Hargreaves wrote that on single house lots, whoever tested the compaction rarely certified the fill as good enough to build on without piers, which left the classifier treating it as uncontrolled. If your lot has been filled, find the earthworks testing records before the soil test. Uncontrolled fill covers how to tell.

Deeper drying west of the range. Hargreaves also pointed out that the published climate maps put country just west of Toowoomba in a zone where Hs reaches 3 m. There, AS 2870-2011 asks for at least three holes rather than one, and the class carries a "-D" suffix for deep-seated movement. The engineer decides the zone, so ask which one the quote assumes.

Soft coastal ground. On the coastal lowlands, soft compressible clay, shallow groundwater and acid sulfate soils turn a two-hole job into a deeper investigation. Flood and acid sulfate mapping usually show this before you book. Site classification in Brisbane and SEQ explains what those estates involve.

Distance and access. Regional towns and outer growth corridors carry travel costs. Steep lots, narrow side setbacks and soft wet ground can rule out a truck-mounted rig, and hand augering or a tracked rig costs more and reaches less.

A Class P result. The footing is then designed specifically, with more investigation and design fees. Class P sites lists the triggers.

New South Wales

Sydney quotes sit at or slightly above Queensland's for the same scope, mostly because of travel across the basin and rig availability. The ground question is which rock the lot sits on. The shale of the western growth corridors weathers to reactive clay, the sandstone suburbs are often close to benign, and the Newcastle coal measures are more reactive again. Chan and Mostyn (2009) mapped climate factors from 64 NSW weather stations, so a lot's zone can be read off a published map before anyone visits.

Two things add cost more in NSW than elsewhere. Shallow rock ends a borehole early, which can mean another hole and moves risk into the excavation budget. And steep sites in 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 tracked rig at a higher rate.

Victoria

The base price in Melbourne is much the same as Brisbane's and Sydney's. What lifts the average is the basalt clay of the Newer Volcanics west and north of the city. Li et al. (2016) tested 47 sites across 37 Melbourne suburbs. On that one geological unit, a sample from Tullamarine came back at about 1.1 percent strain per pF and one from Williams Landing at 11, a tenfold spread, and values above 6 were common in the west and north. With a spread like that, identifying the profile is not enough, so lab work appears in Melbourne quotes more often than in sandstone Sydney.

South Australia

Adelaide is where the ground, not the travel, sets the price. The Keswick and Hindmarsh clays under much of the city are highly expansive, and the semi-arid climate dries them deeply. Jewell and Mitchell (2009) went back to movement records from two grassed sites on highly expansive black clay near Adelaide. At one, a paddock fenced off from stock in 1978 after a drought, the ground rose 82 mm over a single winter. It shrank fastest in late spring as maturing grasses drew the moisture out, and once the dried grass was left on the ground as mulch rather than grazed, movement almost stopped the following summer.

AS 2870-2011 builds that depth into the minimum scope. Wherever Hs is 3 m or more, the Standard asks for at least three boreholes per site, each to at least 0.75 Hs, which is 3 m in Adelaide, and the class carries a "-D" suffix for deep-seated movement (H1-D, for example). So an Adelaide quote starts from a bigger job, and more blocks end up needing lab testing and heavier footing design. Regional South Australia is a travel story again.

Western Australia

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

Can a desktop report replace the soil test?

No. No desktop study, including ours, gives a site classification a certifier will accept, and ours does not yet cover Western Australia. The site investigation decides the class.

What a desktop report gives you before anyone drills is the mapped geology, slope, nearby bore logs, groundwater, hazard overlays and an indicative reactivity range. That is enough to see which of the cost drivers above apply, compare lots and brief the engineer. If you already have lab Iss results, the free AS 2870 site classification calculator works out the class from them.

How do you keep the cost down?

1. Check the lot before booking the rig, so fill, soft ground or shallow rock is in the scope from the start rather than a second visit.
2. Check the scope against your state's usual triggers. A Melbourne quote with no lab allowance on basalt clay, or a coastal Queensland quote scoped as a standard two-hole job, is worth a question.
3. Ask what happens on refusal. In shale, sandstone and limestone country, the answer decides whether a second visit gets billed.
4. Get the classification and footing design quoted together, and send the site plan, footprint, known history and any earthworks testing records.
5. Test several lots in one mobilisation where you can, and book early. Travel does not scale with the number of holes, and rush jobs carry a premium.

Who to call is in how to get a geotechnical report.

Common questions

How much does a soil test cost?

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 soil test cost in Queensland?

A standard residential site classification with two boreholes starts at about $700 in 2026 for a suburban lot in Brisbane or elsewhere in Queensland. Classification with footing design typically runs $1,200 to $2,500, and a full investigation with laboratory testing starts around $3,000.

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. AS 2870-2011 lists Adelaide's design depth of moisture change as 4.0 m, which means at least three boreholes to at least 3 m on each site, and more blocks need laboratory testing and a heavier footing design than a typical suburban Brisbane lot.

Is a soil test the same as a site classification?

For a house, generally yes. The residential "soil test" is an AS 2870 site classification: limited drilling, logging of the profile, sometimes laboratory testing, and a class letter for footing design. A full geotechnical report is a larger scope with founding recommendations.

Can a desktop report be used for building approval?

No. A desktop assessment can indicate the likely reactivity and scope the investigation, but the classification used for footing design must come from site-specific investigation and testing.

How long does a soil test take?

Typically one to three weeks from booking to report, driven mostly by drilling availability rather than the assessment itself. Busy construction periods stretch that.

To check a lot before commissioning the fieldwork, generate a desktop report for the address, or see a sample report to check what it covers.

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

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
• Hargreaves, B. (2005). 20 years of AS 2870 in South East Queensland: a personal view. Australian Geomechanics, Vol 40 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.

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