Introduction
When something goes wrong with building or renovation works, most homeowners assume the problem will be simple to prove: the work is defective, so the builder must fix it. But construction disputes are rarely that straightforward. Whether the issue involves water ingress, structural cracking, incomplete works, poor workmanship, or cost blowouts, you will almost always need an independent expert to establish what has actually happened, why, and what it will cost to fix.
Expert evidence sits at the centre of almost every building dispute in Victoria. Courts and VCAT rely heavily on experts because construction issues are technical and specialised, and – as the label suggests – requires expert appraisal to acquire correct specifications of defects and suggested fixes. The quality of your expert report, and how well your lawyer manages the expert process, can make or break your claim.
Below is a clear guide to what expert evidence is, why it matters, and how the expert process works in building cases.
What Is Expert Evidence?
Expert evidence is the independent opinion of a qualified specialist (usually a building consultant, structural engineer, quantity surveyor or other construction professional) engaged to assess the building work and provide unbiased conclusions.
In building disputes, an expert’s job is to:
- Identify defective or incomplete work
- Explain the cause of each issue
- Recommend how to rectify it
- Estimate the cost of rectification
An expert must not give an opinion about who is legally responsible for the defect, as that is a matter for the tribunal or court to determine. The expert’s primary duty is not to you, but to the court or VCAT.
Why Expert Evidence Is Critical in Building Disputes
- You cannot prove defects without technical evidence
Most defects, such as slab movement, waterproofing failure, poor drainage, structural misalignment or non-compliant workmanship, require specialist expertise to properly identify and analyse. Courts expect expert evidence to clarify exactly what the defect is, whether it is minor, major, structural or merely aesthetic, what caused it (for example, poor construction, design failure or inadequate maintenance), and whether further investigation is required. Experts also explain what rectification work is necessary. Without this technical foundation, even seemingly obvious issues cannot usually be proven.
- You need costings,and they must be credible
To claim compensation or rectification, you must be able to demonstrate what the defect will cost to fix, and this must be supported by credible costings. Experts provide detailed estimates that include labour rates, material costs, quantities, contingencies and the appropriate builder’s margin. Both sides are expected to provide costings, even for items they dispute, so that the tribunal has more than one methodology and valuation to consider. Accurate and transparent costings help the court assess the true financial impact of the defects.
- Expert evidence shapes negotiation and settlement
Expert reports often drive whether a dispute resolves early or becomes protracted. A clear, well-prepared expert report can narrow the issues, eliminate misunderstandings, reduce time and cost, and give both parties a realistic appraisal of the risks. Once the experts outline what the defects are and how they should be rectified, builders and owners frequently reach agreement because the technical dispute becomes clearer and more grounded in objective analysis.
- The court will expect expert evidence
In Victoria, both the County Court and VCAT place significant weight on expert evidence in building matters. For example, VCAT has a Practice Note so that all expert evidence will be made in accordance with their requirements (Expert Evidence Practice Note (PNVCAT 2). Expert input is essential to resolving questions of liability, assessing quantum (the cost of rectification), determining causation and evaluating whether the proposed rectification methodology is reasonable. Because these issues are technical, a case without proper expert support is almost always on unstable ground. Courts and tribunals rely on experts to guide their findings, making expert evidence one of the most important components of any building claim.
What It Must Include
A compliant expert report includes:
- details of the expert’s qualifications, experience, and instructions and a statement confirming this
- date and location of inspections
- photographs
- identification of each defect or incomplete item
- recommended rectification or completion
- costings for both parties’ proposed scopes of work
Experts must also clearly distinguish between:
- defects vs incomplete works
- technical vs aesthetic issues
- major vs minor defects
If further investigation is needed (e.g., moisture testing, invasive inspection), the expert must say so.
Expert Conclaves
After each party provides its own expert report, the tribunal or court will typically order an expert conclave. This is a private meeting of the experts, supervised by an independent facilitator, aimed at narrowing the issues. During the conclave, experts discuss what they agree on, what they disagree on, reasons for their views, and recommended methods and costings.
The process is strictly confidential except for the signed joint report and Scott Schedule produced at the end. Experts cannot communicate with clients or lawyers during the conclave. A conclave is not a negotiation – experts are not there to push their client’s position. Their only task is to express their honest, professional view.
The Joint Report / Scott Schedule
The joint report is one of the most influential documents in a building dispute. It sets out, item by item, the areas where the experts agree and disagree, along with each expert’s comments and costings. It also includes any recommendations from the facilitator and notes where the experts have agreed to split the difference on particular issues. Because the joint report presents the technical matters in a structured and objective way, courts rely on it heavily. It distils the true points of dispute, and provides a clear roadmap for settlement discussions or, if needed, the hearing itself.
Concurrent Evidence
In many building cases, the experts give evidence concurrently. This method allows the experts to explain their reasoning directly to the court, while the judge or VCAT member can ask questions in real time. The experts are also able to question each other, which helps clarify technical disagreements and highlight points of consensus. The result is evidence that is clearer, faster to present, and far more transparent. This approach has been shown to significantly reduce hearing time and help decision-makers quickly get to the heart of the technical issues.
What Happens If You Don’t Have Expert Evidence?
Without expert evidence, your claim is significantly weakened. You cannot reliably prove technical defects, establish what caused them, or substantiate the cost of rectification. In the absence of your own expert report, the court may simply accept the other side’s expert as the more credible source of information. Failing to obtain expert evidence early can lead to claims being dismissed, compensation being reduced, and the dispute becoming more drawn-out and expensive. It can also place you at a serious strategic disadvantage during negotiation.
When Should You Engage an Expert?
It is best to engage an expert as early as possible. You should do so when you first discover defects, experience delays or incomplete work, receive an allegation of defective work from your builder, or begin preparing to issue or respond to a claim. Expert involvement is also crucial before negotiation or mediation, as an early report can prevent misunderstandings, narrow the issues, and stop the dispute from escalating unnecessarily.
Choosing the Right Expert
Selecting the right expert is critical. Your lawyer can help identify an expert who has the appropriate building expertise, relevant litigation experience, and a strong record of recent site inspections. A strong, well-prepared expert adds significant weight to your case. Conversely, a poorly chosen or inexperienced expert can undermine your position and weaken your claim.
Conclusion
Expert evidence is the backbone of building disputes. Whether you are a homeowner, builder, developer, or contractor, an independent expert report gives you clarity, credibility, and the technical foundation required to resolve your matter.
If you need assistance with a building issue, obtaining expert evidence, or navigating the dispute process, our construction team can guide you every step of the way.
Please get in touch with Warlows Legal today with any queries, using our contact information below.
