Why independent beats free
Underpinning companies offer free inspections, and an independent engineer charges $600–$1,200 for a report. It is tempting to take the free option, but the two products are not the same thing. The free inspection is a sales visit: the company profits only if you buy their repair, so the assessment leans, quite naturally, towards their repair. The engineer sells nothing but the opinion itself. They earn the same fee whether the answer is "monitor for a year", "fix your stormwater" or "underpin the south-east corner", which is precisely what makes the answer worth having before you commit to work that typically costs $10,000–$40,000.
What an engineer assesses
A structural engineer inspecting a moving house is answering four questions. What is the movement pattern: which parts of the building have moved, in which direction, and does the crack pattern match? What is the cause: reactive clay drying out, a leaking pipe, poor drainage, tree roots, or uncompacted fill? How severe is it: cosmetic, serviceability, or structural? And what should happen next: monitoring or action? On modest damage, a recommendation to monitor cracks for 6–12 months is common and sensible; our guide to whether you need underpinning at all explains why that patience usually pays.
Report and soil test costs
A standard inspection and written report runs $600–$1,200 for most homes. If the engineer goes on to design a remediation, specifying pile locations, depths and loads for a contractor to build from, design work can take the total to around $2,500. A geotechnical soil test costs $400–$1,000 and involves boring to sample the soil profile. You will not always need one, but expect it where the cause is unclear, where reactive clay depth matters to method choice, or where piles or new footings must be designed to a known soil classification. Against the price of the work itself, both are small numbers that stop expensive guessing.
What the report should contain
A useful report does three things. It attributes a cause: not just "the footing has moved" but why, because the fix depends on it. It recommends an action: monitor, repair the cause, or underpin, and if underpinning, which family of method suits the diagnosis. And it defines the scope: which walls or corners, over how many metres or how many piles, so a contractor can price it. A report that stops at describing the cracks you can already see, or that recommends "further investigation by a specialist contractor", has not finished the job; ask the engineer to complete the cause and scope before you pay contractors to interpret it for you.
Using the report and finding an engineer
The report is also your quoting instrument. Hand the same report to every contractor and ask each to price the same specified scope. Suddenly the quotes are comparable: same walls, same metres, same method family. Without it, one company quotes six piles, another quotes resin under half the slab, a third quotes the whole perimeter, and you are comparing three different jobs, not three prices.
Look for a structural or geotechnical engineer who is genuinely independent: not employed by, affiliated with or paid referral fees by a repair company. Search for consulting structural engineers in your area who offer residential inspections, ask directly whether they have any commercial relationship with underpinning contractors, and check they carry professional indemnity insurance. If the movement started with cracking in your brick walls, bring your dated monitoring photos; a record of how fast things are moving is the single most useful document you can give them, and it can shortcut months of the engineer's own monitoring of the symptoms.
One independent report given to three contractors produces three comparable quotes. Three free inspections produce three different diagnoses, each matching what that company sells.
Ready to find out what it'll cost?
Up to three quotes from licensed local firms. Free, no obligation.
Common questions
Do I really need an engineer before getting quotes?
You can get quotes without one, but they will be hard to compare and each will reflect what that contractor sells. A $600–$1,200 report defines the problem and the scope so quotes compete on price and workmanship, not on competing diagnoses.
Do I always need a soil test as well?
No. If the cause is obvious, such as a leaking pipe under a dropped corner, the engineer may not need one. Expect a soil test ($400–$1,000) where the clay profile matters to method choice or where piles and footings must be designed to a soil classification.
Will the engineer also supervise the underpinning work?
They can, usually for an additional fee, and on larger jobs it is worth it. Many engineers will design the remediation, then inspect at key stages so you have independent sign-off that the work matches the design rather than relying on the contractor's own word.
Can I use a building inspector instead of a structural engineer?
A pre-purchase building inspector can flag that movement exists, but diagnosing cause and specifying a fix is structural engineering. If a building inspection raises subsidence concerns, the next step is still a structural engineer's report.