Certifier ordered to pay $4,026 after approving outdated plans for the wrong house (ACAT, 2026)

What happened

The owner, a qualified engineer of about 40 years' experience, began a knockdown-rebuild on a block in Aranda as an owner builder from around 2020. The first plan was a straw-bale house. Those plans were approved by an earlier certifier and building approval was issued, with inspections carried out at the footings and pre-slab stages in December 2020 and May 2021. The owner then changed direction and decided to build a prefabricated house instead, with the components imported from Poland. Revised architect's plans were drawn up in April 2022, marked "For Client Approval". The first certifier withdrew from the project.

The owner met the respondent certifier on site in March 2023 and paid his quote of $3,300 in full and in advance. The quote was for "re-approval" of the existing project from 14 April 2023, and the certifier had advised by email that the earlier government approval fees would stay valid if he took over before mid-April. A change of certifier form was signed on 14 April 2023. There was no separate written contract. The certifier accepted he knew from this early stage that the straw-bale plan had been abandoned in favour of the prefabricated house.

On 5 May 2023 the certifier stamped the superseded straw-bale plans as approved and signed a site work notice and a building commencement notice. The owner said he only realised what had been approved when the documents were emailed to him on 1 June 2023, and said he raised it by phone several times and was told it could be "fixed up" later. The certifier then inspected the site on 22 June and 7 July 2023, filled out inspection records certifying that the work had been "generally constructed in accordance with the approved plans", and allowed building work to continue, even though the only approved plans were for the straw-bale house. He did not give copies of those records to the owner or to the ACT Government at the time. Their existence was not disclosed to anyone until he emailed them to the tribunal in September 2025.

Around September or October 2023 the certifier was told his professional indemnity insurance would not be renewed, and his licence as a certifier lapsed on 30 October 2023. He did not tell the owner. At that point no plans for the prefabricated house had ever been approved. The owner found out from Access Canberra by email on 8 December 2023. A further change of certifier form was later lodged naming a replacement certifier; the owner said he had never signed it. The Territory issued a stop work notice in July 2025, and the project remained stalled. The owner, who told the tribunal he wanted a "pathway to certification", lodged a civil dispute application in April 2025.

What each side wanted

Before the first tribunal the owner said the certifier had failed to provide the certification services he was engaged for, and that the work he did do was either done incorrectly or did not move the project towards certification. He itemised losses of $33,473, including the full $3,300 certification fee, engineering design certificates of $1,980, $330 and $550, $7,000 in project management fees, $4,261 in rates, $4,650 in insurance, $1,452 to another certification business and an estimated $10,000 for updated plans, and asked for the tribunal's then maximum civil award of $25,000. The certifier said he had retired from certification work and that another certifier had been arranged to take over. With the help of a person he put forward as an expert in the Building Act 2004, he argued that as a licensed owner builder the owner bore at least as much responsibility as he did for the building work and its progress. The first tribunal ordered a refund of 40 per cent of the fee, $1,320, and allowed none of the consequential losses; the owner appealed, again seeking $25,000.

What the tribunal decided

The appeal tribunal set aside the order of the original tribunal and ordered the respondent to pay the appellant $4,026 within 28 days.

The appeal tribunal also dealt with a naming problem. The respondent had been recorded as an individual "trading as" a company, which it said is not possible: a person can trade under a business name and a company can trade under a business name, but an individual cannot trade as a company. On the evidence the proper respondent was the individual certifier, and the tribunal said it would amend the respondent's name accordingly.

The appeal was run as a review of the first decision rather than a fresh hearing, with limited new evidence allowed. The $4,026 is more than the $1,320 ordered at first instance but well short of the $25,000 claimed. The published text stops part-way through the reasoning on the remaining grounds, so it does not show how the $4,026 was broken down.

Why the tribunal decided it that way

The appeal tribunal found the first tribunal had made a legal error by awarding damages without identifying or working through the cause of action. The owner's claim was a contract claim, and in substance it alleged breach of an implied term that the certifier would exercise due care and skill. To succeed on that kind of claim the appeal tribunal said the owner had to establish a contract, a breach of the duty of care and skill, loss or damage with each item quantified, causation, that the loss was reasonably foreseeable, and mitigation of loss where relevant. The first tribunal had instead reasoned mainly from the responsibilities the Building Act 2004 places on a licensed owner builder, which the appeal tribunal said was a correct description of the statutory scheme and of the owner's position towards third parties, but not a sufficient answer to the contract claim between these two parties.

On the content of the duty, the appeal tribunal followed a Supreme Court decision holding that what a certifier must do to exercise reasonable care and skill is shaped by the certifier's statutory duties under the Building Act 2004: reviewing and, if appropriate, approving plans before work starts; inspecting at the relevant stages to check that work complies with section 42 of that Act, meaning it accords with the approved plans and is done properly and skilfully; and, where not satisfied, refusing an inspection certificate and giving the builder reasonable directions to achieve compliance. Section 42 and the certifier's monitoring role matter because they protect public confidence in the building process.

Applied here, the appeal tribunal held it was beyond argument that the certifier breached that duty. He formally approved plans he knew had been superseded three years earlier; he inspected on 22 June and 7 July 2023 and verbally approved work continuing although he knew a prefabricated building was being built and that no plans for it had been approved; he completed inspection records certifying compliance with approved plans and then gave them to nobody; and he let work continue until his licence lapsed at the end of October 2023 while still not having approved the right plans. His explanation that he had intended to re-approve the old plans so the owner could avoid paying a second approval fee did not save him: whatever was discussed in March 2023, by early June the owner had raised the problem, and from the June inspection onwards the certifier had a continuing duty not to approve or permit work other than in accordance with properly approved plans. The appeal tribunal accepted the certifier was "endeavouring to assist" rather than acting on a frolic of his own, and declined to make any finding about whether a later inspection record or the second change of certifier form had been falsified, saying it was neither feasible nor safe to do so and not necessary to decide the appeal.

The appeal tribunal rejected two of the owner's grounds. The unusual role played by the certifier's helper at the first hearing was not, by itself, an error, because the tribunal may set its own informal and flexible procedures under sections 7, 23 and 26 of the ACT Civil and Administrative Tribunal Act 2008. It was also not unfair to look at the plans and inspection records the certifier produced late, which in fact helped the owner's case, although their disappearance for years added to the picture of a lack of professional competence. The appeal tribunal said the owner's own statutory duty as an owner builder not to carry out work except in accordance with approved plans was relevant to contributory negligence under Part 7.3 of the Civil Law (Wrongs) Act 2002 and possibly to causation, but did not reduce the force of the finding of breach. The published text ends part-way through the discussion of the remaining grounds, so the full reasoning on the consequential losses, contributory negligence and the make-up of the $4,026 is not available.

What this means if you are in a similar position

If you are in a similar position, this decision shows that paying a professional for certification work creates a contract, and that a court or tribunal will usually read into it an implied promise to exercise due care and skill, measured by what the relevant legislation requires that professional to do. It also shows that being an owner builder, with your own statutory duties, does not by itself answer a claim that the professional you paid failed to do their job. Those two questions are separate, and the decision shows a tribunal is expected to work through the contract claim element by element rather than deciding the matter on the statutory scheme alone.

The decision is also a plain illustration of the difference between proving a breach and proving a loss. The breach here was described as fundamental and beyond argument, yet the amount ordered was a small fraction of the $33,473 of losses listed, because each item of loss has to be quantified, caused by the breach and reasonably foreseeable, and the other side's conduct can be weighed against your own. Records matter too: inspection records that were never handed over, and plans that could not be found for years, were treated as part of the evidence about the standard of the work.

In disputes of this kind most people start by putting the problem in writing to the professional or business involved, setting out what was paid for, what was and was not done, and what they want fixed or refunded, with a deadline. If that written demand does not resolve it, the next step is usually an application to the tribunal that handles civil disputes in that state or territory.

How to apply: our step-by-step guide to a ACAT application. More decisions: ACAT cases and builders and building defects.

Source: MITCHELL v WARING (Appeal) [2026] ACAT 33 (read the full decision). This summary was prepared from the published decision for general information. It is not legal advice, and the tribunal’s own reasons are the authoritative record.