Sader v Renbar Construction Pty Ltd

1. The appellants lodged a Notice of Appeal on 10 July 2025, which is within the time provided by r 25(4)(c) of the Civil and Administrative Tribunal Rules 2014 (NSW).
2. The Notice of Appeal identified six grounds of appeal. However, the only grounds of appeal that were pursued at the appeal hearing were as follows."

Ground 1: The Tribunal erred in Law by rejecting the [appellants'] claim pursuant to s 18E (2) of the Home Building Act 1989 (NSW) (HB Act) in relation to the waterproof roof membrane and related waterproofing measures when the Tribunal positively found that the defects were of a different kind and the applicants did not know of the other deficiency when the warranty was previously enforced.

Ground 2: As to the water leak from the bedroom 1 ensuite affecting study and internal areas below, the Tribunal erred in law in finding that the [appellants'] expert knew what the cause of the leak was when the available evidence of both experts was that the defect comprised a defective "0" ring and in consequence of which s 18E(2)(b) of the HB Act was not engaged to preclude the claim.

Ground 4: The Tribunal erred in law by failing to find that the respondent was estopped from relying on a defence of res judicata in connection with the water leak from the bedroom 1 ensuite to the study below when there was an express representation made by counsel for the respondent that the applicants could commence proceedings to address the issue in another jurisdiction in the event that it eventuated that both experts were wrong as to the cause of the water leak.

1. On 2 October 2025, the appellants filed a 2,189 page three volume Court Book.
2. Helpfully, at the appeal hearing the appellants provided a bundle of relevant documents being pages 148 - 49, 234 - 235, 348, 356 - 357, 364, 375, 388 - 392, 542 - 544 together with selected pages of the transcript of the Tribunal proceedings and selected pages of the Primary Decision.

1. The appellants relied on submissions filed on 17 October 2025, and undated submissions titled Further Outline of Submissions on Ground 4.

1. The respondent did not file a Reply to Appeal.
2. On 25 November 2025, the respondent filed:

(1) a Response to Amended Grounds of Appeal; and

(2) lengthy submissions.

1. Suffice it to say, the respondent submits that the appeal should be dismissed, with costs.
2. In its Response to Amended Grounds of Appeal, the respondent:

(1) denies that any ground raises a question of law; and

(2) submits that leave to appeal is required and that leave should be refused.

1. We will set out the substance of the respondent's submissions later in these reasons.

1. Section 80 of the Civil and Administrative Tribunal Act 2010 (NSW) (NCAT Act) sets out the basis upon which appeals from decisions of the Tribunal may be brought. That section states that an appeal may be made as of right on any "question of law" (that is, not an "error of law"), or with leave of the Appeal Panel on any other grounds (s 80(2)(b)).

1. In Prendergast v Western Murray Irrigation Ltd [2014] NSWCATAP 69 at [13], the Appeal Panel set out a non-exhaustive list of possible questions of law giving rise to an appeal as of right:

(1) whether there has been a failure to provide proper reasons;

(2) whether the Tribunal identified the wrong issue or asked the wrong question;

(3) whether a wrong principle of law had been applied;

(4) whether there was a failure to afford procedural fairness;

(5) whether the Tribunal failed to take into account relevant (that is, mandatory) considerations;

(6) whether the Tribunal took into account an irrelevant consideration;

(7) whether there was no evidence to support a finding of fact;

(8) whether the decision was so unreasonable that no reasonable decision-maker would make it.

1. These matters were clarified and expanded by the Appeal Panel in Unique Commercial Group Pty Ltd v Cusumano [2024] NSWCATAP 204 (Unique). Relevantly, the Appeal Panel stated:

35 It has become commonplace for parties, and their lawyers, to simply copy from various items listed in Prendergast as questions of law and present them in a Notice of Appeal, without modification of clarification to meet the circumstances of the relevant appeal.

36 Commonly, that will be wrong.

37 What constitutes a question of law is vexed and context dependent in the sense that the distinction between matters of fact and of law may turn on the circumstances in which the question arises: Targeted Property Investments Pty Ltd v Look Up Technologies Pty Ltd (No 2) [2023] NSWSC 416 at [33(4)], citing Thomas and Naaz [2023] NSWCA 40 at [52] and Da Costa v The Queen [1968] HCA 51; (1968) 118 CLR 186 at 194; [1968] HCA 51.

...

39 Therefore, discernment and care must be taken to ensure the grounds relied upon by the appellant, properly understood, raise questions of law and arise in the proceedings; or whether leave is required.

40 In light of the above authorities, a question of law should be articulated with sufficient precision to allow an Appeal Panel to identify it as a pure question of law.

1. Clause 12 of Sch 4 of the NCAT Act provides that, in an appeal from a decision of the Consumer and Commercial Division of the Tribunal, an Appeal Panel may grant leave to appeal only if satisfied that the appellant may have suffered a substantial miscarriage of justice because:

(1) the decision of the Tribunal under appeal was not fair and equitable; or

(2) the decision of the Tribunal under appeal was against the weight of evidence; or

(3) significant new evidence has arisen (being evidence that was not reasonably available at the time the proceedings under appeal were being dealt with).

1. The principles to be applied by an Appeal Panel in determining whether or not leave to appeal should be granted are well settled. In Collins v Urban [2014] NSAWCATAP 17_,_ the Appeal Panel conducted a review of the relevant cases at [65] - [79] and concluded at [84](2) that ordinarily it is appropriate to grant leave to appeal only in matters that involve:

(1) issues of principle;

(2) questions of public importance or matters of administration or policy which might have general application; or

(3) an injustice which is reasonably clear, in the sense of going beyond merely what is arguable, or an error that is plain and readily apparent which is central to the Tribunal's decision and not merely peripheral;

(4) a factual error that was unreasonably arrived at and clearly mistaken; or

(5) the Tribunal having gone about the fact finding process in such an unorthodox manner or in such a way that it was likely to produce an unfair result so that it would be in the interests of justice for it to be reviewed.

1. Even if an appellant establishes that they may have suffered a substantial miscarriage of justice in the sense explained above, the Appeal Panel retains a discretion whether to grant leave under s 80(2) of the NCAT Act. An appellant must demonstrate something more than that the Tribunal was arguably wrong: Pholi v Wearne [2014] NSWCATAP 78 at [32].
2. As the Appeal Panel stated in Unique:

41 Where the ground of appeal does not raise a pure question of law, the appellant may seek leave to appeal.

42 The principles governing an application for leave to appeal under the NCAT Act are well‑established and are repeated in many decisions of the Appeal Panel, often quoting Collins v Urban [2014] NSWCATAP 17. They are the same principles applied by the courts. It is enough, as a summary, to refer to Secretary, Department of Family and Community Services v Smith (2017) 95 NSWLR 597; [2017] NSWCA 206 at [28], where Gleeson JA (on behalf of the bench) said:

Only if the decision is attended with sufficient doubt to warrant its reconsideration on appeal will leave be granted. Ordinarily, it is only appropriate to grant leave where there is an issue of principle, a question of general public importance, or an injustice which is reasonably clear, in the sense of going beyond what is merely arguable. It is well established that it is not sufficient merely to show that the trial judge was arguably wrong.

(Citations omitted)

43 Further, as Basten JA said (White JA agreeing) in Hungry Jack's Pty Ltd v Fourtounas [2020] NSWCA 325 (Hungry Jack's) at [9]:

... more is required than identification of error on the part of the trial judge, even if it can be said that the error is reasonably clear. Generally, the court will also need to be satisfied that there is a matter of some public importance engaged and that the costs of further litigation are not disproportionate to the amount in issue. Further, it should be established that, to leave any putative error uncorrected, would give rise to a substantial miscarriage of justice." (Citation omitted)

1. The appellants say that the appeal raises important questions of principle and public policy concerning the proper interpretation of s 18E(2) of the Home Building Act 1989 (NSW) (HB Act), in particular the operation of s 18E(2)(b) regarding "statutory knowledge".
2. Section 18E(2) provides:

(2) The fact that a person entitled to the benefit of a statutory warranty specified in paragraph (a), (b), (c), (e) or (f) of section 18B has enforced the warranty in relation to a particular deficiency in the work does not prevent the person from enforcing the same warranty for a deficiency of a different kind in the work (the other deficiency) if -

(a) the other deficiency was in existence when the work to which the warranty relates was completed, and

(b) the person did not know, and could not reasonably be expected to have known, of the existence of the other deficiency when the warranty was previously enforced, and

(c) the proceedings to enforce the warranty in relation to the other deficiency are brought within the period referred to in subsection (1).

1. The appellants submit the Primary Decision gives rise to an injustice that is plain, material, and apparent on the face of the record, with the Tribunal's reasons disclosing internally inconsistent findings and a misapplication of s 18E(2)(b) of the HB Act that undermine the beneficial intent of the statutory scheme.
2. The appellant submit that one of the core issues in this appeal is whether, in cases where experts for both parties agreed on the cause of a defect, here a faulty "O-ring", and that opinion later proved incorrect, it is lawful to conclude that the appellants "could reasonably have expected to have known" of some other deficiency when the warranty was previously enforced. The appellants submit that that reasoning conflicts with the purpose and wording of s 18E(2)(b).
3. The appellants submit that it would be unjust for the decision to stand. They submit that Grounds 1, 2 and 4 all raise questions of law. Alternatively, they submit that leave should be granted under cl 4 of Sch 4 cl 12 of the NCAT Act on the basis of a substantial miscarriage of justice; the Primary Decision being (a) not fair and equitable, (b) against the weight of evidence, or (c) attended by legal error.
4. The respondent submits that the appeal is an attempt to disturb factual findings made by the Tribunal will respect to three items of alleged building defects being
   • Item 1: defective waterproofing of the roof membrane and related waterproofing measures;
   • Item 2: water ingress from inadequate falls in drainage lines;
   • Item 3: a water leak from the first bedroom ensuite.
5. The appellants submit that the Tribunal found each defect to be a deficiency "of a different kind" for the purposes of s 18E(2) of the HB Act, yet "nevertheless dismissed all claims on [the] grounds that the [appellants] had actual or constructive knowledge". The appellants submit that that approach was legally and logically erroneous.
6. The respondent submits that as the appellants had brought proceedings previously against it in the Supreme Court of New South Wales (Supreme Court Proceedings) for defective works, they needed to establish those matters in s 18E(2) of the HB Act to be able to pursue a further claim for defective works.
7. The respondent submits that s 18E(2) requires the appellants to demonstrate four matters:

(1) first, that the defect they now seek to enforce is of a different kind (the other deficiency) than that pursued in the Supreme Court Proceedings;

(2) secondly, that the other deficiency existed when the work was completed by the respondent: s 18E(1)(a);

(3) thirdly, that the appellants did not know, and could not reasonably be expected to have known, of the existence of the other deficiency when the warranty was previously enforced (that is, when the matter was before the Supreme Court: s 18E(1)(b); and

(4) fourthly, the proceedings brought in the Tribunal to enforce the other deficiency are brought within time: s 18E(1)(c).

1. The respondent submits that the appellants failed to demonstrate the third matter referred to above (that is, that they did not know, and could not reasonably be expected to have known)of the existence of Items 1 - 3 when the matter was before the Supreme Court) being a question of fact, (the Primary Factual Finding) and accordingly were precluded from pursuing them in the Tribunal: Primary Decision at [57], [60], [65] - [66].
2. In addition, the respondent submits that:

(1) the appellants also failed on Item 2 because they failed to establish the existence of the defect;

(2) the appellants failed on Item 3 because:

(a) they failed to establish that there was a defect in the waterproof membrane;

(b) they failed to establish that the existing remediation was not sufficient;

(c) the respondent established that the cost of the total ensuite replacement propounded by the appellants was disproportionate beyond the invoiced cost of $5,656.20 for the current remediation, which was accepted by the Tribunal.

1. The respondent submits that as no challenge is made to the Ancillary Factual Findings, any error(s) with respect to the Primary Factual Finding (if established) are not material to the outcome with respect to Items 2 and 3, in the sense that any error is not capable of affecting the outcome of the appeal: Bimson, Roads & Maritime Services v Damorange Pty Ltd [2014] NSWSC 734 at [41] per Beech-Jones J citing Australian Broadcasting Tribunal v Bond [1990] HCA 33; (1990) 170 CLR 321 at 353 per Mason CJ; Barefoot Timber Pty Ltd v Wright [2024] NSWCATAP 252 at [30] - [31].
2. In addition, the respondent submits that none of the Grounds raise pure questions of law, with all grounds as formulated relying on:
   • questions of fact alone, including facts not found: Orr v Cobar Management Pty Ltd [2020] NSWCCA 220 at [48], [109].
   • mixed questions of fact and law: Bimson at [39].
3. Finally, the respondent submits that the appeal attempts to challenge factual findings, all of which were available to the Tribunal on the materials before it, and that no basis for leave is articulated or established.
4. For the reasons that follow, we consider that the respondent's submissions to be persuasive.

1. In brief written submissions, the appellant says that Ground 1 constitutes a manifest error on the face of the record. The claimed error is said to be an internal inconsistency between pars [54] and [96] of the Primary Decision.
2. The oral submissions of the appellants' counsel did not expand on the written submissions in any meaningful way.

1. In summary, the respondent makes the following submissions.
2. First, the appellants have not raised a question of law.
3. Secondly, there is no error:

(1) in simply making a wrong finding of fact, unless there is no evidence to support that finding; and

(2) if the finding of fact, or the inference (or the refusal to make a finding of fact or draw an inference) is perverse, in the sense that it is contrary to

the overwhelming weight of evidence;

1. Thirdly, the gravamen of the appellants' complaint appears to be directed to the Tribunal's comments at [96] concerning the appellants not having the requisite knowledge as found at [56], but the factual finding at [56], which is the dispositive finding, is not challenged in this appeal by the appellants.
2. Fourthly, When the reasons are read in their entirely there is no inconsistency between [56] and [96] because the Tribunal was carrying out two separate tasks.
3. The first task the Tribunal conducted was to

(1) correctly identify the two part test required by s 18E(2): Primary Decision at [45];

(2) correctly identify each part of the test is objectively assessed: Primary Decision at [51];

(3) making a factual finding with respect to the first part of the test that the defect with respect to Item 1 constitutes a deficiency of a different nature under s18E(2): Primary Decision at [54);

(4) making a further factual finding that this defect ought reasonably to have become aware to the appellants to the Supreme Court Proceedings: Primary Decision at [56]; and

(5) concluding that as the appellants had not satisfied the requirements of s 18E(2), they cannot bring a claim in these proceedings: Primary Decision at [57], [70].

1. The second task undertaken by the Tribunal was:

(1) having already dismissed the appellants' claim for the reasons expressed in above, the Tribunal then made findings on the merits of the alleged defects on an "if found" basis: Primary Decision at [71];

(2) when determining Item 1 on an "if found" basis, the Tribunal:

(a) found that the appellants had established the existence of the defect;

(b) rejected the respondent's s18F defence; and

(c) accepted the appellants' evidence as to quantum.

1. It is while carrying out the second task that the Tribunal made the comments at [96]. The respondent submits that those comments are not a new factual finding inconsistent with the dispositive factual findings made at [56] - [57)], and so much is clear from the language used at the very start of [96]:

In the circumstances that the merits of the defects are being considered, it follows that a finding has been made ... to the effect that ...

1. Fifthly, the respondent submits that the appellants have raised no question of law, therefore that the appellants require a grant of leave in relation to Ground 1, and that leave should not be granted.

1. It is appropriate to briefly summarise the Primary Decision.
2. The background is that the appellants own land in Connells Point. On 1 July 2014, the first appellant entered into a costs plus contract for an initial contract sum of $1,650,000, with the respondent to demolish an existing dwelling and construct a new house.
3. On 23 January 2018, a final occupation certificate was issued, with handover of the construction taking place on 14 April 2018.
4. On 22 November 2019, the respondent commenced proceedings in the Supreme Court of NSW in respect of unpaid works.
5. After a hearing held from 14 - 17 February 2022, the Supreme Court published its judgment, finding that the respondent was entitled to be paid the unpaid balance of the total cost of works as found by its expert Mr Madden. From that amount damages to which the first appellant was entitled arising from delay and the defective works was to be deducted. The Court directed the parties to confer and agree on the resultant figure and on the orders to be made to give effect to its reasons.
6. On 27 March 2022, final orders were entered.
7. The appellants filed the present proceedings in the Tribunal on 18 January 2024. They sought a money order in the sum of $222,315.46 for alleged breaches of s 18B of the HB Act, and alleged breaches of the respondent's duty of care under s 37 of the Design and Building Practitioners Act 2020 (NSW).
8. At [6] - [29] of the Primary Decision, the Tribunal sets out the background to the dispute, the procedure to be followed, found it was satisfied that it had jurisdiction to hear and determine the matter, and summarised the issues in dispute.
9. At [30] - [70], the Tribunal considered the appellants' entitlement to bring the proceedings in the Tribunal. At [31], the Tribunal states:

In relation to the claim for breach of statutory warranty ... the builder submitted that the owners fell outside the statutory exception in HBA s 18E(2) to the general law that there was one claim for breach of contract and were precluded by the general law from litigating the matters in the current proceedings. The defects alleged in the current proceedings were said to be of the same "kind" as those litigated in the earlier proceedings. Further, the owners clearly had knowledge or ought to have known from the owners' expert's reports in the earlier proceedings about the defects now sought to be litigated - for example, the roofing defects now referred to were readily detectable by the owners' expert and formed part of his instructions to investigate and report on in the earlier proceedings. The owners made a forensic decision not to reserve a potential for expansion of item 12 in the earlier proceedings; that decision was not dependent on the builder's conduct. There was no appeal of any decision in the earlier proceedings.

1. At [32] - [43] the Tribunal explores the items claimed by the respondent to have been considered in the Supreme Court Proceedings before setting out s 18E(2) at [44]. At [45] - [47] the Tribunal sets out the relevant principles governing s 18E(2), noting that:

45 The principles were not in issue, rather, their application to the facts. HBA S18E(2) expressly contemplates that an owner (or relevant subsequent owner) can bring separate claims for distinct alleged defects - "deficiency of a different kind"- that allegedly breach the same set of statutory warranties. Whether or not the requirements of s 18E(2) are met, particularly paras (b) and (c), are questions of fact: Shousha v Habuco Projects PL [2020] NSWCATCD, unreported, 14 April 2020, at [55]. Those requirements, especially para (b) which relates to the knowledge of the claimant at time of previous enforcement of warranty, are expressly inconsistent with the general law that there is one cause of action for breach of a contractual promise to carry out works in a good and workmanlike manner expounded in Conquer v Boot [1928] 2 KB 336, а decision which was approved and followed in Onerati v Phillips Constructions PL (1989) 16 NSWLR 730 in a general law context independent of s 18E. A claim for breach of contractual requirements concerning all alleged detects must be brought in the one proceeding. The general law was confirmed to apply to HBA Pt 2C as it then stood in Honeywood v Munnings [2006] NSWCA 215; (2006) 67 NSWLR 466 esp at 470, [2006] NSWCA 215. According to the explanatory note to the Home Building (Statutory Warranties) Bill 2006 (NSW), the amendments to HBA s 18E in Pt 2C (together with amendments to s 18D) were made to overcome that decision.

46 The foregoing was extensively analysed, in the context of amendments adding further alleged breaches of statutory warranty in Parkview Constructions P/L v Owners SP 90018 [2023] NSWCA 66 ...

1. In light of the "historical, current and legal" context set out earlier in the primary Decision, the Tribunal then considers Item 1, commencing at [49]. The Tribunal states (paragraph breaks added to [54] for ease of understanding):

54 I am prepared, with significant hesitation, to accept (for the purposes of considering the knowledge element below) that, in the circumstances of this case and despite the owners' expert's answers in cross-examination and the ambiguities in his evidence in the earlier proceedings described above, it was established that the defects alleged in the current proceedings constituted a deficiency of a different kind" from the defect alleged and found in the earlier proceedings, as required to satisfy HBA s 18E(2).

Although instructed to identify all defects, apparently carrying out an investigation to do so on a roof which did not appear different at the time of the assessment for the current proceedings and referring in general terms to cracks and other failures in the membrane, the expert focused in his costings in the earlier proceedings on a particular defect in a particular part of the roof which had similar consequences and effect in terms of water penetration but required a different manner and scope of remediation. The localised nature of the identified defect resolved in the earlier proceedings made it a distinctive component within the waterproofing protection structures. That will not always, or perhaps even often, be the case.

One can easily envisage an integrated waterproofing system comprising all the elements which were the subject of complaint in the current proceedings. If I am later found to be wrong on the knowledge element for this alleged defect, my acceptance should not be treated as positive finding and would need to be revisited for a finding on the matter.

55 Turning to the knowledge element in HBA s 18E(2)(b), it may be that the extent of consequences and effect of the roof membrane and related defects as now identified, and the required manner and scope of remediation, could reasonably have become known to the owners, not through their own observation, but only through expert evidence that it was not reasonable to expect to have been obtained with the original manifestation of the roof membrane defect being focused in a small roof area.

56 However, the expert's answers in cross-examination in the current proceedings set out above clearly indicated that his expertise was instructed to be applied and was applied to all defects that could be reported at the time and that his 2019 scope of remedial work included rectification of the same photographed areas as those photographed for his 2023 report. The non-localised references to membrane cracking and failings also set out above indicated that he had identified a broader set of defects than his rectification costing focused on. On that evidence the defects now complained of ought reasonably to have become known to the expert and through the expert's knowledge to the owners for the purposes of and prior to the earlier proceedings. The owners' evidence in the current proceedings confirmed their knowledge of the owners' expert's report of 21 February 2022 for the purposes of the earlier

proceedings.

57 Accordingly, even if the evidence was sufficient to establish that "a deficiency of a different kind" was in issue in the current proceedings, the owners did not establish the required absence of actual or constructive knowledge under HBA s 18E(2)(b) for the dispensation to apply. Absent such exception, there was no independent cause of action.

(emphasis added)

1. At [70], the Tribunal concludes that the appellants' claims must be dismissed.
2. Then, the Tribunal states:

71 In the event that I am later found to be wrong on my conclusions concerning the owners' preclusion from litigating all or some of the matters the subject of these proceedings, I turn to consider the concurrent expert evidence, the conclave report and the experts' reports and make findings on the merits of the owners' claims in the current proceedings.

72 The owners' preclusion from bringing these claims is, I have found, by reason of principles of law applied to the facts and not because the Tribunal lacked jurisdiction to determine the claim (a matter discussed earlier in these reasons), so it seems apposite to proceed to make findings on the merits of the claims.

(emphasis added)

1. At [73] - [81], the Tribunal then sets out the relevant principles governing loss arising from defective and incomplete building works, referring to well-known authorities such as Bellgrove v Eldridge (1954) 90 CLR 613; [1954] HCA 36, Tabcorp Holdings Ltd v Bowen Investments Pty Ltd (2009) CLR 272; [2009] HCA 8 and various decisions of the Tribunal and the Appeal Panel.
2. At [82] - [105], the Tribunal then considers the "Alleged defective works - consideration and conclusions", including Item 1 at [83] - [96]. The Tribunal concludes at [96]:

In the circumstance that the merits of the defects are being considered, it follows that a finding has been made (going further than my assumption described earlier) to the effect that the award in the earlier proceedings was for a defect of a different kind from those litigated in the present proceedings, and that the owners did not have the requisite knowledge, despite the ambiguity in the owners' expert's report and evidence described earlier. That cuts the ground from under the builder's submission that no compensation should be awarded in the current proceedings because the compensation awarded in the earlier proceedings covered the complete scope of roof waterproofing defects.

1. We have set out the parties' submissions above. In summary, the appellants claim that the inconsistency between [54] and [96] resulted in some (unarticulated) error on a question of law.
2. We reject that proposition. In our view, it is clear that the appellants are challenging factual findings in [54] and [56] of the Primary Decision, which findings were readily available to the Tribunal, and made out in the Tribunal's lengthy and considered reasons for decision on the issue.
3. We see no inconsistency at all between [54] or [56] and [96]. As the Tribunal stated, the language used by the Tribunal [71] and in [96] make it clear that the Tribunal is simply considering the counter-factual in the event the Appeal Panel or the Supreme Court concluded that it was in error in reaching those findings. We put this proposition directly to the appellants' counsel at the appeal hearing. He could not persuade us that the Tribunal's remarks at [96] were anything other than the Tribunal's conclusions on alleged defects were the Tribunal in error in concluding that the appellants' claims should be dismissed by reason of the application of s 18E(2) of the HB Act.
4. We see no question of law having been raised by the appellants, less still any error on a question of law. This ground of appeal is dismissed.
5. Nor would we grant leave to appeal. We see no substance in any argument that the Primary Decision was not fair and equitable, against the weight of evidence, or otherwise attended by legal error.

1. The appellants note that, "for context", it can be observed that in the Supreme Court Proceedings, the experts for the appellants and respondent met on site to discuss and further assess the root cause of this defect and to ascertain why there was continued water ingress. At that time, both experts agreed that the likely cause was a faulty or damaged O-ring. The cost to repair was said to be minimal, and both experts agreed that the O-ring should be replaced. It was on this basis that Defect 12 was not pressed, and this was communicated to the trial judge.
2. In summary, the appellants submit that:

(1) the Tribunal erred in law by concluding that the appellants expert "knew or could reasonably have known" of the true cause of the leak [Primary Decision at [65], when the uncontroverted evidence was that both experts agreed the cause was a faulty O-ring and that repair had been implemented during the Supreme Court proceedings;

(2) at [102], the Tribunal acknowledged that the O-ring was not the true cause of the water escape, yet still found against the appellants on the basis of knowledge. This reverses the "temporal logic" of s18E(2)(b):, as the appellants cannot "know" what the experts and the Court also did not know at the time;

(3) given the beneficial consumer purpose of the HB Act and "critically" s 18E(2), the Tribunal should have found that the appellants satisfied the statutory test and were entitled to recover for the ensuite/study defect.

(1) no question of law is raised;

(2) the appellants' submissions mischaracterise the Tribunal's findings at [65]; even if the appellants can establish an error on a question of law, such an error cannot be material because the Tribunal made various other unchallenged factual findings which separately and independently disposed of the appellants' claim for Item 3;

(3) leave to appeal should not be granted as the appellants:

(a) have made no effort to identify that the Tribunal's findings were against the weight of the evidence , and the factual finding made by the Tribunal at [65] was open to it;

(b) the issues does not involve any issue of principle, or a question of public importance or matters of administration or policy that might have general application.

1. As noted, this ground deals with Item 3, being the water leak from the first bedroom ensuite. The Tribunal considered this defect at [61] - [66] of the Primary Decision.
2. At [61] - [63], the Tribunal summarised the appellants evidence on the issue, stating:

61 ... The owners' expert said that the origin of the leak was defective ensuite waterproofing in the form of waterstops, undersized shower outlet and membrane failure. The owners alleged that extensive damage had occurred to the rooms below the ensuite, specifically a study.

62 [In the Supreme Court Proceedings] the "O" ring solution had been pursued by the owners as the simplest and cheapest if in fact that was the cause and the remediation worked. The owners adopted and carried forward (with their own plumber) that solution and, when it did not resolve water penetration and damage to the study and other areas on the building level below, implemented a further solution with their own remedial builder at an invoiced cost of $5,656.20, which was to seal with silicon sealant the hole in the upper floor concrete slab and divert any water to the exterior through a drainage pipe which was also silicon-sealed in. ...

63 The owners' expert said that the potential failure of sealant meant that the sealant was not a final solution (which again was contested and is dealt with below). The owners relied upon quotations from the remedial builder who had performed what the owners contended were the interim measures that had been put in place to date. The remedial builder quoted $121,176.62 for the complete remediation which substantially involved wholesale removal of the ensuite bathroom and reinstatement after repair of the leak source and the water-affected areas below. The owners' expert had assessed the cost of such complete remediation at $134,998.86 and pointed to the customised features in the bathroom as producing a markedly higher cost than standard bathroom. ...

1. The Tribunal then notes at [64] that this was submitted to constitute an acute difference from the solution (replacement of an O-ring to prevent leaking from the floor-mounted bath tap) that was stated as the cause by the respondent. As recorded in the conclave report in the Supreme Court Proceedings, the appellants' expert had costed the O-ring repair at $1,248.00 and the respondent at $710.00.
2. The Tribunal considered at [65] that the difficulty with this contention is that it avoids the central issue in respect of seeking to use 18E(2) of the HB Act to escape preclusion from bringing the claim. The Tribunal stated:

The "deficiency" in waterproofing, even if it was of a different "kind" from a leaking tap which it appears to be because of its different origin, was clearly known, or could reasonably be expected to be known, to the owners in the earlier proceedings because their expert identified the source or origin of the water leak and damage (the result of the deficiency) as at least requiring further investigation, in his report of 21 January 2022 for the earlier proceedings. It is a reasonable inference that, if the experts had carried out at the time of the earlier proceedings the investigation that the owners' expert carried out which produced his conclusion on source in his report for the current proceedings, then the owners would have known from their expert that conclusion and litigated it in the earlier proceedings. It was apparently not pursued in the earlier proceedings while a minimalist solution was investigated and implemented, but the position to contend for further investigation and reporting was not reserved or, if a mechanism for such reservation was not available or was refused by the builder or the Court, pressed for determination prior to judgment. Rather, the testing of the minimalist solution extended into mid-2023 when judgment in the earlier proceedings was delivered in early 2022.

1. Consequently, the Tribunal found that the appellants had failed to satisfy the requirement in18E(2)(b).
2. As with Ground 2, we see no question of law having been raised by the appellants, less still any error on a question of law. This ground of appeal is dismissed. It appears to us that the appellants are seeking to challenge a factual finding of the Tribunal which was plainly available to the Tribunal on the materials before it.
3. Accordingly, the appellants require a grant of leave. We do not grant that leave, as we do not consider that any ground advanced warrants a grant of leave. Leave is only usually granted where these matters involve an issue of principle, a question of public importance, an injustice which is reasonably clear or that the Tribunal has gone about its factfinding process in such an unorthodox manner that it is likely to have produced an unfair result. We are not satisfied that any of those factors are established.

1. In its submissions dated 17 October 2025, the appellants submit:

(1) the Tribunal erred in law by failing to find that the respondent was estopped from relying on res judicata in relation to the ensuite leak claim;

(2) the respondent's counsel expressly represented in written submissions dated 23 March 2022 that "[i]n the event the [first appellant] wishes to pursue the Item, then there is nothing stopping the [first appellant] from pursuing this claim (which is not otherwise statute-barred) in a Court or Tribunal of appropriate jurisdiction";

(3) judgment was entered in the Supreme Court on 27 March 2022 without that representation being withdrawn. The appellants were entitled to rely on it and did so. It was therefore unconscionable for the respondent to assert res judicata later. The Tribunal should have found the respondent is estopped from doing so.

1. In the appellants' Further Outline of Submissions on Ground 4, the appellants set out what they describe as "the factual circumstances that resulted in [the appellants] withdrawing this defect "as distinct from the expanded defect 12" in the Supreme Court Proceedings.
2. In conclusion, the appellants submit:

(1) in the factual circumstances of the matter, it cannot be said that it was unreasonable to omit the item in the earlier proceedings because the respondent invited the omission by saying the claim could be pursued elsewhere. Anshun estoppel cannot succeed where the respondent induced the very conduct that gives rise to the alleged omission;

(2) although the Tribunal concluded that it was not satisfied the appellants had established a defect in the ensuite waterproof membrane, or that remediation undertaken was inadequate, they submit that the Tribunal ought nonetheless to have found that they were entitled to recover the reasonable out of pocket expenses incurred in engaging a third party contractor to address the ensuite leak affecting the study, being $5,142.00.40;

(3) leave to appeal should be granted and the Tribunal decision should be set aside.

1. Apart from submitting that Ground 4 does not state with precision a question of law (including that the reasons for decision were inadequate), the respondent submits that the appellants' estoppel argument cannot succeed for some nine reasons. These are as follows.
2. First, the statement was made by the respondent's counsel, not the respondent.
3. Secondly, the submission was nothing more than a written submission made to the trial judge, Stevenson J, which his Honour ultimately rejected.
4. Thirdly, the appellants' legal representatives are obliged to make their own independent enquiries, form their own independent view and provide independent advice to their client rather than simply relying on statements contained in written submissions made by opposing counsel in adversarial proceedings that raise issues of law.
5. Fourthly, reliance and detriment are for the appellants to establish, they are not presumed: Kramer v Stone [2023] NSWCA 270 at [91] and [95]. It was necessary for the appellants to establish that they would have acted differently, but for their assumption. The appellants gave no evidence on these "central matters" at all: Kramer v Stone at [92].
6. Fifthly, in order for the representation to be made by the respondent, the appellants have to demonstrate that their counsel had authority on behalf of the respondent to waive any rights the respondent may have had under the contract or at law generally.
7. Sixthly, the onus lies on the appellants to demonstrate the existence and terms of any agency as between the respondent's legal representatives and the respondent: Pavolovic v Universal Music Australia Pty Ltd [2015] NSWCA 313 at [21], [150], [154] and [162].
8. Seventhly, there was no evidence before the Tribunal establish the existence and terms of any agency as between the respondent's legal representatives and the respondent. At the very least:

(1) questions would have had to have been asked of the respondent's director on this issue. This did not occur; and/or

(2) documentary evidence would have been needed to be tendered on this issue. There was no such evidence.

1. Eighthly, to the extent there was a waiver (which is denied), any waiver would be a variation of the respondent's rights under the contract and accordingly would need to be signed and in writing by both parties (as required by s 7E and P 1 of Sch 2 of the HB Act) in order to be enforceable pursuant to s 10 of the HB Act.
2. Ninthly, as Stevenson J properly pointed out, the situation the appellants find themselves in today is a matter that the appellants, through his legal advisors, brought upon themselves.

1. During the course of the Supreme Court Proceedings, on 22 February 2022, the appellants' solicitors wrote to the respondent's solicitors informing them that the appellants' expert was unable to provide a definitive opinion regarding the cause of the ensuite water issue, and indicated that a further investigation would be required which could not be done at short notice. The email continued:

In those circumstances, where there is the possibility that this is a major defect, we propose that we should inform his Honour of the above, and we intend to withdraw our clients' claim for this item, subject to the right for Dr Sader's to take this matter further, if so advised.

1. In an affidavit before the Tribunal, the first appellant relevantly stated that:

... Given the cause of defect 12 had not been properly identified, and a proper rectification methodology being able to be agreed or even determined, this defect was withdrawn because it could not be properly dealt with by the Court, given the hearing of the matter had concluded at that time. ...

1. At [31] of the Primary Decision, the Tribunal noted that:

The owners made a forensic decision not to reserve a potential expansion of Item 12 in earlier proceedings; that decision was not dependent on the [respondent's] conduct. There was no appeal of any decision in the [Supreme Court Proceedings].

1. At [43] of the Primary Decision, the Tribunal further noted that:

Further argument on the "Item" referred to, being the expanded item 12, was not permitted by the Court when it was raised by 25 March 2022; the owners conceded that the drainage defect was not pressed. Near the conclusion of the discussion on expanded item 12, the following exchange occurred between the Court and the owners' counsel (it was extracted as part of the documents attached in the opening outline for the owners that marked MI1):

Counsel: Can I assume that there will be - do I assume that there is no estoppel issue or res judicata that arises with respect to item 12 if it's dealt with elsewhere?

His Honour: I don't propose to say anything about that. Of course not. This is yet another matter that Dr Sader, through his legal advisers, has brought upon himself, to be frank."

1. Having observed at [65] that the appellants had failed to satisfy the requirement of s 18E(2)(b) in relation to Item 3, the Tribunal states, in relation to Item 12 (being Protective covers for floors and decks):

On the same factual matrix [the appellants] are precluded from raising the expanded item 12 in the current proceedings.

1. The matter complained of by the appellants is the "express representation made by counsel for the respondent that the [appellants] could commence proceedings to address [Item 12] in another jurisdiction in the event that it eventuated that both experts were wrong as to the cause of the water leak".
2. At [183] of the judgment in the Supreme Court Proceedings, the Court stated:

During the hearing it was agreed that it was necessary for [the parties' experts] to investigate this matter further. The parties have agreed that, if this defect is to be pressed, I may deal with this matter on the papers once Mr Hall's and Mr Finnane's further views are known.

1. The appellants submit that when the respondent filed submissions as to the orders it sought after the Supreme Court's judgment was published on 25 February 2022, the respondent's submissions stated that:

In the event the [first appellant] wishes to pursue the Item, then there is nothing stopping the [first appellant] from pursuing this claim (which is otherwise not statute barred) in a Court or Tribunal of appropriate jurisdiction.

1. The appellants further submit that when the matter returned before Stevenson J on 25 March 2022 for consideration of the competing proposed orders the Court directed following publication of the reasons, the following exchange then occurred:

His Honour: The judgment will reflect that, that is the first thing. Mr Hyde, defect 12 is not pressed, even though you have spent half a page discussing it.

Mr Hyde: It is pressed in this sense: if Your Honour has my submissions there, issue two, defect 12, essentially what has happened is Your Honour directed the two experts to go away and look at the leak, they did, they attended the site together. They initially thought it was an O Ring on a tap that was causing the leak, they replaced that in the hope it would solve the problem, it did not solve the problem. Mr Hall went back to plan A, which was his assessment of the value of that defect."

1. The appellants say that during the hearing on 25 March 2022, their counsel expressly raised the assumption that they would not face any estoppel argument in future proceedings relating to item 12, and that while Stevenson J declined to comment, this was the appropriate juncture for counsel for the respondent to correct his representation that the matter could be pursued elsewhere, no such correction being made.
2. We consider that there is substances in the respondent's position that there was no evidence to support the proposition that its counsel had authority to make the representation he did such that it bound the respondent. In Pavlovic, relied on by the respondent, the Court of Appeal, per Beazley P at [150], with whom Bathurst CJ and Meagher agreed, citing Lucke v Cleary (2011) 111 SASR 134 stated:

(1) as a general proposition, a solicitor does not have ostensible authority to bind his or her client to a contract.

(2) that general proposition, however, is subject to the qualification that, in the context of litigation, a legal practitioner has ostensible authority to bind his or her client to a contract which relates to and, in particular, compromises that litigation. In CIC Insurance Ltd v Bankstown Football Club Ltd [1994] NSWCA 359; 8 ANZ Insurance Cases 61-232], Kirby P drew a clear distinction between ostensible authority in litigious and non-litigious matters;

(3) even so, in the context of litigation the practitioner's authority to bind his or her client to a contract is confined to a contract that actually and genuinely relates to the litigation.

I agree with what was said by the President in relation to the question of ostensible authority. A solicitor's ostensible authority to bind his or her client to an agreement, in the context of litigation conducted on the client's behalf, does not extend to agreements resulting from negotiations, which if unsuccessful, may or may not end up in litigation.

1. To similar effect, see Meagher JA at [160], "[t]he appellant's solicitor ... did not have actual or ostensible authority to bind his clients to some other course, and did not purport to do so".
2. Given those principles, we see no error by the Tribunal. We are fortified in that view by recognising that reliance and detriment are for the appellants to establish, they are not presumed: Kramer v Stone at [91] and [95], and that it was necessary for the appellants to establish that they would have acted differently, but for their assumption. The appellants gave no evidence on these matters: Kramer v Stone at [92].
3. We discern no question of law having been raised by the appellants. Indeed, the appellants put the error squarely as a factual one, submitting that "in the factual circumstances of the matter", it cannot be said that it was unreasonable to omit the item in the earlier proceedings because the respondent invited the omission by saying the claim could be pursued elsewhere.
4. We do not consider that this ground warrants a grant of leave. We are not satisfied that this ground involves an issue of principle, a question of public importance, an injustice which is reasonably clear or that the Tribunal has gone about its factfinding process in such an unorthodox manner that it is likely to have produced an unfair result.

1. As the Appeal Panel noted recently i_n Tanwar Institute of Professional Studies Pty Ltd v Ruggeri_ [2025] NSWCATAP 326, and in words which we adopt in this appeal, it is difficult to escape the conclusion that the appellants are simply seeking to reagitate factual findings of the Tribunal that were available to it.
2. As the Appeal Panel has stated on many occasions, an appeal does not simply provide a losing party in the Tribunal with the opportunity to run their case again: Ryan v BKB Motor Vehicle Repairs Pty Ltd [2017] NSWCATAP 39 at [10]; Nguyen v Nguyen [2025] NSWCATAP 238 at [40].
3. As the Tribunal Guideline, Internal Appeals (November 2023) states at [4], generally, an appeal is not an opportunity to have a "second go" at a hearing.
4. The application for leave to appeal is refused with the consequence that the appeal is otherwise dismissed.

1. The appellants have been unsuccessful on all grounds of appeal. If the respondent seeks its costs of the appeal, it should file and serve an application for costs and evidence in support within 14 days of the date of these orders.
2. If the appellants oppose an order for costs, the appellants should file and serve submissions and evidence in response within a further 14 days.
3. The appellants may reply within a further seven days.
4. The submissions on costs should include a submission as to whether the Appeal Panel may determine costs on the papers and thereby dispense with a further hearing.
5. Submissions are to be limited to five pages.

1. The issue of the costs of the Tribunal proceedings was raised by the appellants. As we understand matters, orders for submissions on costs were made by the Tribunal, and submissions made. If that is correct, we do not propose to deal with the costs of the Tribunal proceedings. That issue should be taken up with the Tribunal through the Registry.

(1) Leave to appeal is refused and the appeal is otherwise dismissed.

(2) If the respondent seeks its costs of the appeal, it is to file and serve any submissions (and if necessary evidence) as to costs within 14 days of the publication of these reasons.

(3) The appellants may respond within 28 days of the publication of these reasons.

(4) The respondent may reply within 35 days of the publication of these reasons.

I hereby certify that this is a true and accurate record of the reasons for decision of the Civil and Administrative Tribunal of New South Wales.

13 April 2026 - Respondent's representation amended from Hooks Lawyers to New South Lawyer's on the coversheet