Ware v Pacific Hydro Portland Windfarm Pty Ltd [2025] VSC 558

1. The power to order the engagement of a single joint expert is found in s 65L of the CPA, which provides:

(1) A court may order that an expert be engaged jointly by 2 or more parties to a civil proceeding.

(2) A court may make an order for the engagement of a single joint expert at any stage of the proceeding.

(3) In making an order to engage a single joint expert, the court must consider -

(a) whether the engagement of 2 or more expert witnesses would be disproportionate to -

(i) the complexity or importance of the issues in dispute; and

(ii) the amount in dispute in the proceeding;

(b) whether the issue falls within a substantially established area of knowledge;

(c) whether it is necessary for the court to have a range of expert opinion;

(d) the likelihood of the engagement expediting or delaying the trial;

(a) by agreement between the parties; or

(b) if the parties fail to agree, by direction of the court.

(5) A person must not be engaged as a single joint expert unless he or she consents to the engagement.

(6) Any party who knows that a person is under consideration for engagement as a single joint expert -

(a) must not, prior to the engagement, communicate with the person to obtain an opinion on the issues concerned; and

(b) must notify the other parties to the proceeding of the substance of any previous communications on the issues concerned.

(7) Unless the court orders otherwise, a single joint expert's report may be tendered in evidence by any of the parties to the proceeding.

1. In assessing how to apply this section to the circumstances of a particular case, the parties referred to a ruling I made in another proceeding involving a similar application in a claim concerning a wind farm_, Baxter v Berrybank Development Pty Ltd ('Baxter')_.[2]
2. In that proceeding, relevantly to the present circumstances, I stated at paragraphs 56 to 60:

Despite the age of the Civil Procedure Act at this stage, there appear to be few authorities considering the use of a single joint expert under s 65L specifically. Most of the directly applicable guidance identified by the parties was drawn from judgments in other jurisdictions, where comparable or equivalent language is used in similar provisions, such as those concerning the use of a court-appointed expert or referee.

The principles used in considering and applying provisions such as s 65L flow from the overarching purpose in the Act. There is no pre-defined test for the section to be directly applied, and the matters set out in s 65L(3) are not a set of criteria to be checked off or counted against one another. Rather, the Court's task appears to be to evaluate the full range of considerations present in a particular case, having specific regard to the items set out in s 65L(3), and form a conclusion as to whether the use of a single joint expert is more consistent with the overarching purpose and effective case-management of the proceeding than the alternative.

There is plainly a traditional presumption in favour of a party being given the opportunity to call all of the evidence in support of its position that it wishes to in respect of a disputed area of a case, and the just and fair conduct of a proceeding will no doubt often require that to occur. However, that position is not absolute - the Act has been described as having 'changed the litigation landscape',[3] and it includes a requirement for parties to seek directions about expert evidence in a proceeding at an early opportunity,[4] as well as provisions for the use of joint and court-appointed experts.[5]

In considering similar provisions to s 65L in New South Wales, in Walker Group Constructions v Bluescope Steel and QBE Insurance, McDougall J stated:

I would be the first to agree with WGC's position that where there are detailed allegations of disputes and those detailed allegations are denied, the appointment of a single expert is unlikely to be productive of any real saving in time or costs. It may readily be conceded that the usual case where a single expert ought be appointed is the one where the matters calling for expert opinion are either essentially uncontentious or relatively uncomplicated, or (in some cases at least) relate only to the assessment of damages. Of course, the general discretion given by r 31.37 [similar to s 65L of the Civil Procedure Act] is not to be read as being, in some way, constrained by those typical situations where it is engaged. Nor can it be suggested that the general discretion conveyed by the rule can only be exercised where those considerations are engaged.[6]

Case-management purposes, and the utility of joint processes in assisting (if not forcing) parties to confer and ultimately clarify or narrow the issues in dispute, have been highlighted as particular advantages of the use of joint experts (or experts appointed independently of parties, in other contexts).[7]

1. It seems that the position in terms of published authorities concerning the use of s 65L has remained unchanged since that time, as the parties did not point to any other published decisions concerning the section since my ruling in the Baxter proceeding. For my part, I have also not identified any further decisions since that time that address the section. As such, I will proceed in the same manner identified in Baxter.
2. In terms of the factors identified for consideration in s 65L(3), I am not satisfied that it could be said that the engagement of two or more expert witnesses to collect noise data would be disproportionate to either the complexity or importance of the issues in dispute, or the amount in dispute in the proceeding.
3. The existence and nature of the alleged noise is clearly a central issue in dispute in the proceeding. Given it is the foundation of the loss and damage claimed by Ms Ware, it seems reasonable to conclude that it is of particular importance to the parties, and also appears likely to be complex in nature, requiring specialised expertise and equipment to measure it for the same reasons that arose in Baxter. Multiple experts would not appear to be disproportionate in that setting, however equally given the approach the parties have agreed on, they would also not seem to be necessary.
4. There is no evidence available in this application concerning the likely cost of the noise data collection exercise. The suggestion from counsel for MDA in the course of the hearing was that the cost was likely to be 'significant' or 'not nothing', however, it appears to be accepted that there is no specific evidence available about this point. There is also no evidence available about the amounts in dispute in the proceeding. It is therefore not possible to form a view about proportionality in this regard.
5. As to whether the issue falls within a substantially established area of knowledge, the parties were not in dispute about this issue. I note that in the Baxter ruling, I concluded based on the material available in that proceeding, that the same issue being addressed in the present application (ie, the measurement of wind farm noise in accordance with the applicable technical standard) did fall within a substantially established area of knowledge. Given the issue is common between the two proceedings and there was nothing identified in the course of the present application that would cause me to doubt the result reached in Baxter, I adopt that conclusion here.
6. As to whether it is necessary for the court to have a range of expert opinions available, this factor has been largely addressed by the fact that all parties agree to the proposed single joint expert approach. Beyond that, the benefit to be gained by having a range of experts performing data collection work concerning the alleged noise appears to be very modest, if it exists at all. The work is essentially technical data collection in nature, resulting in a common set of measurements taken in accordance with the applicable standard, that other experts can then analyse and opine on. The analysis that might be done subsequently may well benefit from a range of expert opinions that can engage with one another. However, that work will be made more efficient and useful by having all parties able to work from the same set of noise data, which the proposed approach allows. Any disagreements between the parties as to the appropriate methodologies for recording that data, or interpretation of the standard, will be able to be addressed in the course of providing joint instructions to the expert selected. There appears to be a particular benefit in allowing such issues to be identified early in the life of the proceeding, when there will be time available to explore and address them, rather than leaving that potential problem to be addressed close to or at trial.
7. There is no real prospect that the proposed approach will delay the trial. Ms Ware's amended writ and statement of claim were filed on 28 March 2025, and the proceeding has not yet been allocated a trial date as there are still a number of interlocutory steps to be completed. There is a prospect that the single joint expert approach will expedite the trial somewhat, as it will largely remove the potential for disputes and delays that might arise from differences in noise data or approaches to data collection between the parties, which would complicate subsequent expert evidence. On balance I consider this is a neutral consideration, however.
8. As to any other relevant considerations, as noted above, I place significant weight on the fact that the parties have agreed to the proposed course, and indicated in the course of the hearing that they consider the matters in s 65L(3) support the making of the order sought.
9. Taking those factors together, I am satisfied that (consistent with the approach taken in Baxter) it is appropriate to make an order under s 65L(1) of the CPA as sought by the parties.

1. The joint position of Ms Ware, Pacific Hydro and Resonate was that all parties should contribute to the single joint expert process, including in relation to the selection of the expert, briefing and provision of instructions, and payment of the cost of that expert process. In contrast, MDA's position was that it did not seek to participate in the single joint expert process and therefore did not believe it should be required to contribute to those aspects of the work involved, and in particular to the up-front cost.
2. The only evidence relied upon in relation to the application was an affidavit of the Pacific Hydro's solicitor, Philip Andrew Stefanovski, sworn 6 June 2025. The affidavit exhibits the history of correspondence between the parties concerning the 'single joint expert' issue, however for the purposes of the present application it is not necessary to address this in any detail.
3. MDA's position is that the expert evidence concerning noise was only relevant to Ms Ware's nuisance claim (which is pleaded against Pacific Hydro) and not to any allegations made against it. As such, it does not wish to participate in and incur the up-front costs of an expert process concerning an issue that it says will not be relevant to its position in the litigation.
4. Further, MDA notes that the CPA is silent on the question of who bears the costs of a joint expert. It argues that, where the costs of that process will ultimately form part of the costs of the proceeding, MDA may still be required to pay some of the costs involved depending on the outcome of the litigation, and the other parties would not be prevented from seeking those costs at that point in time.
5. Finally, MDA says that s 65L does not limit the Court to only ordering a single joint expert in relation to all parties to a proceeding. The section permits an order requiring the engagement of an expert jointly by '2 or more parties'. MDA considers that any interpretation of that provision implying a requirement that the expert be engaged by all parties would unnecessarily fetter the Court's powers in relation to expert evidence under this section.
6. In the course of the hearing, counsel for Resonate indicated that the consent that Resonate had provided to the single joint expert process was predicated on all parties to the litigation being involved in the process. If MDA was permitted not to be involved, then Resonate would also seek to take the same approach and, presumably, reserve its ability to obtain its own evidence about noise data if required.
7. In considering the appropriate outcome to this application, it is useful to note some preliminary matters concerning the language of the CPA. The following passages are of particular present relevance:

(a) As above, s 65L(1) does not expressly require that a single joint expert be engaged by all parties to a proceeding. It provides that 'A court may order that an expert be engaged jointly by 2 or more parties to a civil proceeding'.

(b) Section 65L(7) provides that 'Unless the court orders otherwise, a single joint expert's report may be tendered in evidence by any of the parties to the proceeding.' The use of 'any of the parties' here may be contrasted with the use of '2 or more parties' in sub s (1). It appears clear from this section that, unless the Court makes an order to the contrary, any party can tender a single joint expert's report at trial, regardless of the configuration of parties involved in engaging the expert under sub s (1). Further, if the report is tendered, then any party would be able to make use of it at trial.

(c) Section 65O(1) provides that where a single joint expert has been engaged in relation to an issue, 'a party to a proceeding may not adduce evidence of any other expert witness' on that issue . Once again, the language used is directed at all parties to the proceeding, rather than only the parties involved in jointly engaging an expert.

(d) Section 65N requires 'the parties to the proceeding' to endeavour to agree on instructions, facts and assumptions to be provided to an expert where a single joint expert is engaged, and to seek directions from the Court where agreement cannot be reached.

1. There was some discussion in the hearing about whether the differing references to '2 or more parties' or 'any of the parties' (or similar phrases) in the above provisions connotes some suggestion that s 65L(1) is to be read as including a requirement that a single joint expert must be jointly engaged by all parties to a proceeding (though in fairness, none of the parties pressed this point particularly emphatically).
2. Having regard to the language of the above provisions and the scheme of the CPA as a whole (in particular, Part 4.6, concerning expert evidence) I am satisfied that it is unnecessary to read s 65L(1) as containing any additional limitations beyond what is apparent in the text of the section itself. The sections of the CPA addressing the use of single joint experts are capable of operating harmoniously as they are expressly written.
3. For an expert to be 'joint' they would obviously need to be engaged by two or more parties, but there is no requirement in the CPA that all parties must engage that expert. There appears to be good reason for the section not to be overly expansive in this regard, as it is easy to foresee situations in which an order covering all parties would not be appropriate or desirable. For example, this may be the case where a particular issue only affects a subset of the parties and will clearly not be used by or in relation to certain other parties at trial, or where an issue only arises in a third party claim but does not affect issues between plaintiffs and defendants.
4. Where a single joint expert is engaged, however, limitations are placed on parties' ability to call their own expert evidence on that issue by s 65O. This furthers the objects of ensuring the efficient and cost-effective conduct of the proceeding if the Court has already been satisfied that the engagement of multiple experts on the issue may be disproportionate (s 65L(3)(a)) and/or it is not necessary for the Court to have a range of expert opinions available on that issue (s 65L(3)(c)), for instance. The complement of that restriction is the ability for any party to seek to tender or use the joint expert report at trial, per s 65L(7).
5. Given the presumption that there will only be one expert called on the issue in question, to avoid undermining the utility of the 'single joint expert' process, s 65N requires all parties to endeavour to reach agreement about instructions, facts and assumptions to be provided to the expert. The objects of the CPA and Part 4.6 in particular (noting particularly the object in s 65F(b) of the Part of 'restricting expert evidence to that evidence which is reasonably required to resolve a civil proceeding') are best served by having all parties sign up to the approach that will be taken to a joint expert report in this way, even if all parties are not involved in engaging the expert. This removes, or at least substantially reduces, the prospect of subsequent disputes or disagreements about briefing material and assumptions provided to experts, methodologies used, and the applicability of the expert's results to the issues in the proceeding. It also limits the prospects of parties seeking leave to adduce their own, separate expert evidence on the same topic. In essence, if it is considered appropriate for a single joint expert to be used, then if all parties are required to have some input into how that process will work and seek to reach agreement, they most likely cannot complain about it later on.
6. This approach can operate consistently with the '2 or more parties' language in s 65L(1) relatively easily, since if a party is not involved in engaging an expert on the basis that the area of expert evidence will not affect them at all, they could presumably simply consent to the position reached by the other 'engaging' parties, or at least indicate they have no opinion to offer on the topic of instructions, facts and assumptions. The requirements of the CPA would seem to be satisfied if all parties have the chance to have their input concerning those topics, given they will presumptively be bound by the results.
7. Having concluded that there is no particular requirement in the CPA to approach the application one way or the other, the question becomes whether it is more consistent with the objects of the Part and the overarching purpose in s 7 of the CPA to require that MDA be involved in engaging the expert, including by sharing in the up-front cost.
8. In this regard, I note that s 65H(1) of the CPA provides that 'A court may give any directions it considers appropriate in relation to expert evidence in a proceeding.' Further, as noted above, s 65L(1) provides that 'A court may order that an expert be engaged jointly by 2 or more parties to a civil proceeding.' These powers are broad enough to encompass making orders to provide for either of the two options presented in this application, including in relation to the costs of the expert.
9. On balance, having regard to the above considerations and the circumstances of this proceeding and application, I consider that the approach most consistent with the objects of the CPA is that all parties, including MDA, should share in the cost of the joint expert to be appointed. My reasons for this are as follows.
10. First, this proceeding is different from the kind of case I referred to above where it is clear that an area of expert evidence will not affect some parties at all. I note MDA's position as raised in its correspondence and in the hearing, that it considers the noise data is not relevant to the claim being made against it, and that at this stage it does not propose to seek to adduce any evidence on this issue. However, I consider the other parties' arguments on this issue are well founded, as the question of the existence and extent of the noise is formally in issue amongst all parties.
11. In this regard, Ms Ware's claim pleads that the alleged fraud or improper representations by MDA caused the loss and damage she has suffered that flowed from the nuisance arising from the noise,[8] and her claim in deceit alleges that she has suffered loss and damage by having to experience the nuisance for years in a manner that could have been avoided.[9] MDA denies each of those allegations.[10] Clearly enough, Ms Ware will have to establish the nuisance alleged in order to succeed in her claim, which will involve the use of the noise data under consideration. It would be open to MDA on the current state of the pleadings to seek to establish at trial that there is no nuisance, or that if the nuisance is established, any loss or damage suffered by Ms Ware is minimal or even non-existent. These allegations are not admitted in MDA's defence.[11] As the other parties noted, if the expert process produces data that is favourable to the defendants on this question, one might well expect that MDA would wish to refer to that evidence once it was available at trial.
12. As such, notwithstanding MDA's position that the noise data is not relevant to it and that it does not presently intend to obtain expert evidence on this point, I consider it is a matter that is formally in issue between all parties, including MDA.
13. Second, as above, the CPA provides that all parties to a proceeding may seek to tender or make use of a single joint expert's report at trial. Whether or not MDA wishes to participate actively in the process of engaging the expert, it is clear that the benefits of that process will be available to it to make use of. Further, as counsel for Pacific Hydro noted, the 'issue' being addressed by the proposed joint expert is only the collection of noise data, not its analysis. There would seem to be nothing in the CPA or elsewhere preventing MDA from seeking to adduce its own expert evidence analysing noise data in this proceeding. In circumstances where the issue in question is a live one on the current pleadings between Ms Ware and MDA, I am not satisfied that it would lead to an unjust result to require MDA to contribute to the cost, as well as the process of settling instructions, facts and assumptions involved in that process where it stands to benefit from doing so just as much as the other parties will.
14. Third, it seems to me that there are other benefits that would accrue from the single joint expert process, beyond simply the availability of the common set of noise data. MDA would also benefit (as would the other parties) from a likely smoother, faster and more efficient interlocutory process and trial, where the prospect of disputes arising from differences in assumptions and methodologies between experts are reduced or removed. Similarly, the potential complications arising from the need to harmonise or comparatively assess expert opinions that might have resulted from very different approaches being taken could be largely avoided, compared to the prospect of such difficulties in expert evidence not becoming apparent until close to (or even at) the trial, such as the situation that arose in Uren v Bald Hills Wind Farm Pty Ltd.[12]
15. In a case that appears likely to involve a considerable number of complexities and a significant investment of time and other resources by all parties, the prospects of a smoother identification of the real issues in dispute and potentially a shorter trial are of themselves significant potential savings to the parties. Looking at the case holistically, I think any up-front cost to a potentially unwilling party like MDA should be considered in light of the real potential for reduced costs overall later on.
16. Fourth, the costs involved with the single joint expert exercise will form part of the costs of the proceeding, so they will presumably be recoverable by any successful party or will be borne in any event by any unsuccessful party. The difference here is simply the question of who should carry those costs from now until the point at which the proceeding is finalised. Further, although there is no evidence about the specific costs involved, there is some benefit to all parties in having those costs shared. Even if the amount is a material one, as was suggested, each party will only have to bear 25% of it.
17. Fifth, although I accept it is somewhat unusual to require a party to engage an expert unwillingly, I note that this does appear to be a pathway envisioned by the CPA. In particular, s 65L(4)(b) notes that a single joint expert is to be selected by direction of the Court if the parties fail to agree on the selection. It would seem to follow from this inclusion that there is no guarantee that the parties will have complete control over the joint expert process if an order is made under s 65L(1), including in relation to the costs they might be required to incur (if different experts have different costs and the Court is required to select one, for example). In this regard I do not consider the outcome in this application to be inconsistent with the operation of the CPA.
18. Further, it is trite observe that defendants by definition incur costs in relation to litigation unwillingly. They are rarely parties to court proceedings voluntarily, and defending claims regrettably involves expense. Viewed through this lens, an outcome requiring all parties to incur some cost in a proceeding, where doing so is consistent with the overarching purpose of the CPA and furthers the progress of the litigation, does not appear to be particularly anomalous.
19. Sixth, it bears observing that the scheme of the CPA overall operates to put aspects of the use of expert evidence in civil proceedings much more in the control of the Court, sometimes at the expense of the freedom that parties might previously have had in this regard.[13] In the present circumstances, where the use of a single joint expert is otherwise justified, the CPA would seem to place somewhat less prominence on the individual wishes of the parties, and more on the Court's case-management functions, with a view to best giving effect to the overarching purpose of the CPA.
20. Overall therefore, I consider that this is a situation where it is appropriate to order that the proposed expert be jointly engaged by all parties, with all parties contributing to the cost of doing so equally. This approach best serves the overarching purpose of facilitating the 'just, efficient, timely and cost-effective resolution of the real issues in dispute' having regard to the factors identified in s 9 of the CPA.
21. In particular, I am satisfied that the noise data is relevant to all parties' positions in the litigation and may be taken advantage of by any party at trial, and it is fair that all parties should contribute to the costs of obtaining it.
22. This approach enhances the ability of the parties and the Court to manage the proceeding in a way that limits potential areas of complexity or dispute, by ensuring that all parties work off a common set of data for which they have all had the opportunity to contribute to the relevant instructions and briefing materials. I accept that there is some prejudice to MDA in this setting, in that it is being required to contribute to the up-front cost of an expert that it currently says it does not need or wish to engage. However, I consider that prejudice is outweighed here by the fact that it will gain the benefit of that expert's work in relation to issues that remain in dispute between it and Ms Ware, and by the fact that the use of the single joint expert is likely to lead to broader savings to the parties in an already complex proceeding.

1. For the above reasons, I propose to make orders in the form foreshadowed by Ms Ware, Pacific Hydro and Resonate. I will ask the parties to prepare a form of order reflecting that outcome and submit it within 14 days.
2. The parties did not address the question of the costs of the application in the course of the hearing. Given the issue appears not to have been addressed before, and ultimately the process of authorising a single joint expert under s 65L(1) would have required an application or hearing in any event, I express a provisional view that it is appropriate for the costs of this dispute to be costs in the proceeding.
3. However, in the event any party disagrees with that approach and a consent position cannot be reached, I will ask the parties to file short submissions of no more than two pages on the question of appropriate costs orders, within 14 days.

[1] The application was referred to me for hearing and determination by an order of Goulden AsJ pursuant to r 84.04(1) of the Supreme Court (General Civil Procedure) Rules 2015 (Vic) dated 10 June 2025.

[2] (Supreme Court of Victoria, Baker JR, 12 June 2024).

[3] Mandie v Memart Nominees Pty Ltd [2016] VSCA 4, [42].

[4] Civil Procedure Act 2010 (Vic) ('CPA') s 65G.

[5] Ibid ss 65L-65M.

[6] [2017] NSWSC 678, [10].

[7] See, eg, Wu v Statewide Developments Pty Ltd [2009] NSWSC 587, [11]; Spralja v Bullard & Ors (No 2) [2019] VCC 1799, [11].

[8] Amended Statement of Claim in Melissa Ann Ware v Pacific Hydro Portland Windfarm Pty Ltd & Ors (S ECI 2024 04644, 28 March 2025) [109], [115].

[10] Defence filed on behalf of the second defendant in Melissa Ann Ware v Pacific Hydro Portland Windfarm Pty Ltd & Ors (S ECI 2024 04644, 20 November 2024) [106], [109], [115].

[12] [2022] VSC 145.

[13] See, eg, CPA (n 4) ss 65F(1), 65G(1), 65H, 65I.