Class 2 DBP Registered · Licence 360636C
0410 515 509You’ve noticed damage — cracks, leaks, spalling concrete, a failing facade. Your instinct is to call a builder and get quotes. But if a builder quotes without a proper investigation, you’re comparing guesses, not solutions.
This page explains the investigation process — what an engineer does, what it costs, and why it protects your building and your committee from approving work based on incomplete information.
We see this regularly — a building gets three builder quotes without an engineer’s report, and the committee picks the cheapest one. Here’s what typically goes wrong.
Without an engineer defining the work, each builder is guessing what needs fixing. One quotes to patch the surface. Another quotes to strip back and rebuild. You can’t compare prices when the scope is different — and you won’t know which scope is right.
If the root cause wasn’t diagnosed, the repair treats the symptom. Water continues to track. Steel continues to corrode. The building is back to square one — with the added cost of undoing the failed repair before starting again.
Under the DBP Act, Class 2 building work requires declared designs and compliance documentation. If the builder works without an engineer’s specification, there’s no design declaration, no compliance pathway, and no protection for the owners corporation.
A builder who quoted without investigating will find surprises during the work. Every surprise becomes a variation. Budgets that looked competitive at tender stage can exceed the engineer-specified quote by 30–50% once variations are added.
You wouldn’t send a football team onto the pitch without a game plan. The coach watches film, studies the opposition, identifies weaknesses, and builds a strategy before the players take the field. Without that preparation, eleven players are just running around reacting to whatever comes at them.
A building investigation is your game plan. The engineer studies the building, diagnoses what’s failing, and writes the strategy. The builder executes it. Skip the game plan and you’re paying eleven tradesmen to react to whatever they find behind the tiles.
A building investigation isn’t just a site visit with a clipboard. Here’s the typical process for a strata or commercial building.
The engineer inspects the affected areas, takes core samples, conducts moisture mapping, and may use non-destructive testing (ground-penetrating radar, cover meters) to assess the condition of concealed elements — reinforcement, membranes, substrates. This is the scouting report — understanding what you’re actually dealing with before committing resources.
They identify why the damage is occurring — not just what’s visible. Water ingress through a balcony might be caused by membrane failure, flashing detail failure, drainage design, or a combination. The diagnosis determines the scope. Without it, you’re treating symptoms — like icing an injury without knowing if the bone is broken.
The engineer produces a detailed report — the defects identified, the root causes, the recommended repair methodology, the applicable Australian Standards (AS 4654.2, AS 3600, NCC), and a specification that any qualified builder can price against. This is the playbook every player works from.
With a specification in hand, you send the same scope to multiple builders. Now you’re comparing apples to apples — same methodology, same materials, same standard. The committee can make an informed decision based on capability and price, not guesswork.
The investigation is a small, controlled investment that protects a much larger one.
The cost depends on building size, the number of defect types, and the extent of testing required. A targeted investigation on a single element — one leaking area or a section of spalling concrete — starts from $1,500. Multi-element investigations across larger complexes (facade + waterproofing + concrete + structural) typically range from $10,000 to $25,000.
Put it in perspective: what’s your property worth? A single unit in your building might be valued at $800K–$2M. The building itself could hold $10M+ in combined property value. An investigation starting from $1,500 is a fraction of a percent of what you’re protecting.
You already insure your property against fire, flood, and liability. An investigation works on the same principle — it protects you against approving the wrong scope, hiring the wrong builder, and paying twice when the first repair fails.
The difference? Insurance pays out after something goes wrong. An investigation prevents it from going wrong in the first place.
From one week for a targeted single-element investigation, up to 6–8 weeks for complex multi-element assessments on larger buildings. The timeline depends on building size, access requirements, and how many areas need testing. Your strata manager coordinates access with residents — each unit visit is typically 30–60 minutes.
A $1,500 investigation can prevent $100,000+ in failed repairs, scope variations, and repeat work. We’ve inherited projects where the previous builder worked without a specification and the repairs failed within two years. The owners corporation paid for the original work, then paid again to undo it, then paid a third time to do it properly. That’s like losing three matches in a row because you never studied the opposition — except each match costs six figures.
