119 In Sch 1, which is headed 'Reasons for Determination', the adjudicator included the following:[118]

1. On 31 December 2015, [Duro] issued its monthly progress claim seeking payment totalling $64,361,606.70 plus GST (Payment Claim).

1. [Duro] claims payment of $49,642,958.72 (plus GST) of the total amounts claimed in the Payment Claim in this application for adjudication made up as follows:

1. the amount certified as payable but 'set off' ($34,186,114.38) 2. the amount claimed in respect of the 'Car Dumper Claims' ($14,740,345.92); and

1. part of the amount claimed for commissioning of a control system ($716,498.42)

1. [Duro] seeks payment within 7 days of this determination of $49,642,958.72 plus GST for:

1. the amount certified as payable but 'set off' ($34,186,114.38); and 2. the amount claimed in respect of the Car Dumper Claims $14,740,345.92); and

1. that part of the amount claimed for Paradigm's commissioning works which had not been claimed prior to the Payment Claim ($716,498.42);

1. Pursuant to section 33 of the Act, interest on the above amount from the date the Payment Dispute arose, being 11 January 2016 until the date of payment, at the rate prescribed in section 8(1)(a) of the Civil Judgments Enforcement Act 2004 (WA), being 6% per annum; and that 2. all the costs of the adjudication be paid by [Samsung].

1. In summary, I determine that [Samsung's] set off from amounts it concedes are due to [Duro] is impermissible and that [Duro] is entitled to be paid $34,186,114.38 (plus GST) free of any set-off.

1. For the reasons set out in this Determination, I determine that the adjudicated amount is $49,642,958.72 (plus GST), and that this amount is to be paid by [Samsung] to [Duro] by 24 March 2016;
2. Pursuant to section 33 of the Act, interest on the above amount from the date the Payment Dispute arose, being 11 January 2016 until the date of payment, at the rate prescribed in section 8(1)(a) of the Civil Judgments Enforcement Act 2004 (WA), being 6% per annum.
3. I further direct that the sum of $23,980.00 be paid by [Samsung] to [Duro] by 24 March 2016 being 50% of my fees and disbursements on the basis that I propose to recover the full amount of my fees and charges from [Duro] as provided for in Section 44(5) of the Act.

SCHEDULE 2: CONFIDENTIAL INFORMATION

The following information is confidential:

(1) the identity of the parties;

(2) the identity of the individuals referred to in the Reasons;

(3) the location and nature of the works.

120 There followed the signature of Adjudicator Loots.

121 Severance is an application of a rule of construction derived from the common law: Attorney-General for the State of South Australia v Adelaide City Corporation.[119]

122 Under the common law, the presumption is that legislation is to be read as a whole and indivisibly, although that is not to deny that legislation affected by invalidity may have some valid area of operation if permissible: Harrington v Lowe;[120] Bank of New South Wales v The Commonwealth.[121]

123 Aside from a statutory provision such as s 15A of the Acts Interpretation Act 1901 (Cth),[122] legislation affected by invalidity may have a permissible field of operation by the common law's approach to severance: R v Commonwealth Court of Conciliation and Arbitration, Ex parte Whybrow;[123] Harrington.[124]

124 In Harrington,[125] Brennan CJ, Dawson, Toohey, Gaudron, McHugh and Gummow JJ said:[126]

As to the common law in Australia, the position, as established by the earlier decisions of this Court to which we have referred appears to be that a valid operation for the sub-rules might be preserved after textual surgery by operation of the 'blue pencil' rule so that the valid portion could operate independently of the invalid portion, or, failing that, by treating the text as modified so as to achieve severance. But this latter step may be taken only where in so doing there is effected no change to the substantial purpose and effect of the impugned provision, and, in particular, there is not left substantially a different law as to the subject-matter dealt with from what it would otherwise be. (emphasis added)

125 The position at common law applies equally to legislation and delegated legislation: Harrington;[127] Owners of SS Kalibia v Wilson.[128] In the latter case, Isaacs J said:

No distinction can be made in this respect between a bye-law and a Statute, because, although very different considerations apply in determining the extent of the power granted, when it is given to a municipal corporation, or a Parliament, yet once the limits of the power are ascertained the excess is as unlawful in the one case as in the other, and the partial validity of the act done must depend upon the same principles. (emphasis added)

126 His Honour's reference to the 'same principles' is a reference to the principles of severance under the common law. At that time, s 15A of the Acts Interpretation Act (Cth) had not been enacted.[129]

127 Although the common law presumption is that a statute is to be read as a whole and indivisibly, inferences of intended severability otherwise discernible may be confirmed by regard to the other general rule of construction. The court will endeavour, when more than one interpretation is possible, to adopt that interpretation which will ensure the statute's validity: Waterside Workers' Federation of Australia v J W Alexander Ltd.[130]

128 Where severance of an invalid law is permissible, there can be no reproach that 'the Court would, by sustaining the validity of what is left, be making a law which the Parliament did not make'.[131] On the other hand, where severance of an invalid law is not permissible, if the remaining part were to be upheld, it 'would ... be exceeding [the court's] functions as interpreter of the law to change the character of the legislation, and in effect to enact it separately': SS Kalibia.[132] It would, in that event, be 'to make a new law and not to enforce an old one': SS Kalibia.[133]

129 The common law's approach to severability in relation to legislation and delegated legislation has an analogous operation in other areas of the law including the law of trusts.[134] In Attorney General (New South Wales) v Perpetual Trustee (Co) Ltd, Dixon and Evatt JJ observed:[135]

The truth is that the time-honoured distinction between essential and accidental characteristics is at the root of the test provided by the modern law for ascertaining whether a trust for charitable purposes, found incapable of literal execution according to its tenor, is nevertheless to be administered cy-près. In other departments of the law, however, similar distinctions are in use. Analogies may be seen in the question whether a contractual provision is of the essence; whether a term is a condition or a warranty; in the question whether invalid provisions of a statutory enactment or other instrument are severable or form part of an indivisible whole; in the question whether a law is mandatory or directory, and perhaps in the question whether the substantial purpose of creating a special power of appointment was to ensure a benefit to the objects so that they take in default of its exercise by the donee. (emphasis added)

130 There is a fundamental distinction between a jurisdictional error, on the one hand, and a non-jurisdictional error of law, on the other. A decision tainted by jurisdictional error will, at least in the case of an administrative tribunal or decision-maker, be void. A decision tainted by non-jurisdictional error of law on the face of the record will be lawful and within jurisdiction, but be liable to be quashed, subject to the court's discretion, by a writ of certiorari.[136]

131 In Minister for Immigration and Multicultural Affairs v Bhardwaj,[137] Gaudron and Gummow JJ observed, in effect, that, under the general law, a decision involving jurisdictional error lacks legal foundation and is not properly regarded as a decision at all.[138] In the same case, Hayne J said, in effect, that the decision made purportedly in the pursuance of a duty under a statute which is affected by jurisdictional error is not authorised by the statute and does not constitute performance of a decision-maker's duty under the statute.[139]

132 Their Honours' observations in McBain and Bhardwaj were not, however, directed to the question of partial invalidity. In Plaintiff M 79/2012 v Minister for Immigration and Citizenship,[140] Hayne J (in dissent in the result and finding that the Minister's decision was affected by jurisdictional error) referred to a submission that the Decision Instrument approved by the Minister was severable either by application of s 46 of the Acts Interpretation Act 1901 (Cth), or by the application of general law principles.[141] His Honour did not determine whether the relevant ministerial instrument fell within the operation of s 46 of the Commonwealth Interpretation Act.[142] His Honour said:[143]

It is not necessary to decide whether s 46 of the Acts Interpretation Act applies to the Decision Instrument approved by the Minister. It is enough to observe that the decision recorded in the Decision Instrument was one composite decision: to effect the plaintiff's release from detention by granting him visas of two classes with identified conditions attached to one of those visas. ... [T]hat decision was legally flawed. It cannot be severed into two separate decisions without radically recasting its nature and effect. The whole of the decision relating to the plaintiff should be quashed. (emphasis added)

133 In Cheatley v The Queen,[144] a magistrate made certain orders against the masters of four foreign fishing vessels for fishing in an area contrary to a Commonwealth statute. The magistrate also made orders forfeiting the vessels to the Crown. The majority of the High Court held that the latter order, forfeiture, was within power. Walsh J dissented on that point and held that the order for forfeiture was made in excess of jurisdiction.[145] On the question of severance, his Honour said:[146]

I am of opinion that it is not a valid objection to the orders made by the Supreme Court that they did not relate to the quashing of the whole of the proceedings before the magistrate, but dealt only with the orders for forfeiture: see Reg. v. Lewes Justices; Ex parte Plumpton and District Club Trustees and see S. A. de Smith Judicial Review of Administrative Action 2nd ed. (1968), p. 442. (emphasis added)

134 In Re Skirving; Ex parte Forward (a case also concerning an excess of jurisdiction),[147] Anderson J (Kennedy & Murray JJ relevantly agreeing) said:

The general rule is that where part only of a decision of an administrative tribunal is beyond power, the Court may quash that part without interfering with the remainder: Cheatley v The Queen [1972] HCA 63; (1927) 127 CLR 291 at 308 - 309. Of course, the impugned parts must be capable of severance from the unexceptionable parts. As the learned authors of Wade and Forsyth 'Administrative Law' (7th ed) say at page 329:

'If the bad can be cleanly severed from the good, the court will quash the bad part only and leave the good standing ... [the] cases depend not upon rigid rules but upon the balance of advantage as perceived by the court.'

135 Re Skirving was applied by this court in Re Narula, Ng & Hammersley; Ex parte Atanasoski,[148] although that case concerned an error of law on the face of the record and not jurisdictional error.[149] See also R v Hannan; Ex parte Abbott.[150] In that case, Kearney J referred to Cheatley for the proposition that certiorari may issue to quash a penalty only, leaving a finding of guilt to stand.[151] His Honour said, however, that in the type of case before him, 'in general, the whole conviction of the prosecutor - in the combined sense of the finding that the charge was proved and the penalty imposed - should be quashed'.[152]

136 The case of Coco v The Queen[153] concerned a purported approval by a judge of the installation of a listening device under invasion of privacy legislation. Mason CJ, Brennan, Gaudron and McHugh JJ said:[154]

It follows from what we have already said that [the judge] misapprehended the nature and scope of the power. By so doing, he misconstrued the statute which gave him jurisdiction, addressed an irrelevant consideration and exceeded his jurisdiction. This error might also be characterized as an error on the face of the record.

The extraneous factor to which [the judge] had regard, namely, the perceived necessity to approve entry on to private property for the purpose of installing, maintaining, servicing and retrieving listening devices, not only contributed to the making of the decision to approve the use of the listening devices but it also took the form of an invalid authorization to enter on to private property. No doubt in some circumstances it is possible to disregard that part of the decision that goes beyond power and treat as valid that part of the decision which is within power. But that must become a much more contentious exercise when the invalid part of the decision has influenced the making of the valid part of the decision. In this case, the approval is expressed in such a way as to make it appear that authorization to enter private property was an integral and essential element in the approval to use the listening devices. So much is made clear by the reference to installation in both the paragraph which constitutes the approval and the first condition. In this situation there is no scope for speculation, on the assumption that speculation is legitimate, about what [the judge] would have done had he appreciated that authorization of entry on to private property was beyond power.

If it were necessary to consider the question from the viewpoint of severance, we would come to the conclusion that it is not possible to sever. The fact that what is bad is an integral and essential element of what is good leads to the conclusion that the approval is wholly void. (emphasis added)

137 In Re Media, Entertainment and Arts Alliance; Ex parte Arnel,[155] a decision of the Industrial Relations Commission was challenged on the basis that it was reached in breach of the requirements of procedural fairness. The High Court upheld the challenge. Mason CJ, Brennan, Dawson and Gaudron JJ said:[156]

The decision was ... reached in breach of the requirements of procedural fairness, which requirements are an essential feature of arbitral power. Accordingly, prohibition should issue to the members of the Full Bench directing them not to act on that decision so far as it affects the entitlement, if any, of the applicants to put a case for leave to intervene and, if granted, to put an argument with respect to differential rates for junior employees with twelve months service. To the same extent, certiorari should issue to quash the decision. (emphasis added)

138 The orders made by the court included the following:[157]

Order that a writ of certiorari issue to the first respondents quashing the decision of 19 May 1993 to the extent that that decision affected the entitlement of the applicants to put a case for leave to intervene with respect to differential rates for junior employees. (emphasis added)

139 In Buzzacott v Minister for Sustainability, Environment, Water, Population and Communities,[158] a condition imposed by a Minister on an approval was held to be unauthorised and invalid under (relevantly) the general law. The Full Court said:[159]

It is well established that an invalid condition may be severable where it is not fundamental to the whole of the approval, but where it is it cannot be severed and the whole of the approval is invalid: Kent County Council v Kingsway Investments (Kent) Ltd [1971] AC 72 at 90 per Lord Reid and 102-103 per Lord Morris; Parramatta City Council v Kriticos [1971] 1 NSWLR 140; Winn at [212] - [216] per Stein JA (with whose reasons for judgment Spigelman CJ at [1] agreed); Kindimindi at [56] per Basten JA.[160] (emphasis added)

140 In this case the question is not whether the Act, including having regard to the presumption referred to in [122] above, is to be read as a whole and indivisibly, but whether the Act, properly construed, reveals a legislative intention that an adjudicator's determination under s 31(2)(b) as recorded in or evidenced by his or her decision under s 36, is to operate as an organic and indivisible whole. There is no common law presumption that it does operate that way. Nor does the Act contain an express provision to that effect.

141 The question of legislative intention is to be understood in the manner explained by French CJ, Gummow, Hayne, Crennan, Kiefel and Bell JJ in Lacey v Attorney-General for the State of Queensland:[161]

The objective of statutory construction was defined in Project Blue Sky Inc v Australian Broadcasting Authority as giving to the words of a statutory provision the meaning which the legislature is taken to have intended them to have. ... The legislative intention there referred to is not an objective collective mental state. Such a state is a fiction which serves no useful purpose. Ascertainment of legislative intention is asserted as a statement of compliance with the rules of construction, common law and statutory, which have been applied to reach the preferred results and which are known to parliamentary drafters and the courts. ...

The application of the rules will properly involve the identification of a statutory purpose, which may appear from an express statement in the relevant statute, by inference from its terms and by appropriate reference to extrinsic materials. The purpose of a statute is not something which exists outside the statute. It resides in its text and structure, albeit it may be identified by reference to common law and statutory rules of construction. (footnotes omitted)

142 Similarly, in Saeed v Minister for Immigration and Citizenship,[162] French CJ, Gummow, Hayne, Crennan and Kiefel JJ said:

As Gummow J observed in Wik Peoples v Queensland, it is necessary to keep in mind that when it is said the legislative 'intention' is to be ascertained, 'what is involved is the "intention manifested" by the legislation.' (footnote omitted)

143 We are satisfied that the Act, on its proper construction, does not manifest an intention that an adjudicator's determination under s 31(2)(b), as recorded in or evidenced by his or her decision under s 36, is to operate (if at all) as an organic and indivisible whole. Our reasons are as follows.

144 First, the Act recognises that an adjudication of a 'payment dispute' may, and perhaps typically will, involve the determination of identifiable, divisible, amounts claimed. In other words, the essential statutory task of the adjudicator will commonly involve the adjudication and determination of divisible amounts.

145 Given that the statutory task will commonly involve the adjudication and determination of divisible amounts, and that where there is one final 'amount to be paid' (within the meaning of s 36(c)(i)), it is no more than the mathematical result of the determination of divisible amounts, it is, prima facie, doubtful that the legislature intended that the final, mathematical, result should itself be treated as an organic and indivisible whole.

146 In relation to this first point, the following matters seem to us to be of significance:

1. A 'payment dispute' includes, and will no doubt commonly apply to, a dispute in respect of a 'payment claim'.[163]
2. The definition of 'payment claim' includes the claim made under a construction contract for 'payment of an amount' in relation to the performance of the contractor's 'obligations'.[164]
3. The phrase 'payment of an amount' is apt to include a reference to payment of 'amounts',[165] particularly in this context where, it may be inferred, the legislature understood that itemised progress claims are typically submitted for multiple aspects of work done by a contractor.
4. Each itemised amount in a progress claim by a contractor may itself be a 'payment claim' as defined in the Act.[166] It is, however, doubtful that the Act requires (although it does not forbid) each such itemised amount to be treated as its own separate 'payment claim'. Were it otherwise, the contemporaneous adjudication of each such disputed amount in a progress claim would depend upon the operation of s 32(3)(b) and (c) of the Act. That would appear an unlikely intention to impute to Parliament. Rather, it appears that s 6(a) and pt 3 of the Act as a whole contemplate that a number of divisible amounts claimed for various aspects of work done in a progress claim may be added together and treated as part of the one 'payment claim', and thereby form part of the one 'payment dispute' if the progress claim is rejected by the principal.[167]
5. The foregoing conclusion does not mean that a 'payment dispute' involving an itemised progress claim is somehow to be determined by an adjudicator as a whole without regard to its divisible components. On the contrary, s 31(2)(b), in its ordinary meaning and context, requires the adjudication of each separate component of a 'payment dispute' involving unpaid amounts pursuant to a progress claim. The determination of the 'amount to be paid' within the meaning of s 31(2)(b)(i) in its application to a progress claim comprising divisible amounts, is a mathematical exercise involving the totalling of each component amount for which a party is found to be 'liable to make a payment' within the meaning of s 31(2)(b). It will also involve the mathematical exercise of netting off where divisible amounts are determined as flowing each way.

147 Secondly, other provisions of the Act operate on the basis that a determination may involve a determination of divisible amounts with different consequences. Under s 33, Parliament evidently contemplates that where individual amounts comprise the 'amount to be paid' in s 31(2)(b)(i), some may, and others may not, be appropriately the subject of an order for interest. Also, the reference to 'the amount to be paid and the date on or before which it is to be paid' in s 36(c)(i) is apt to refer to the 'amount or amounts' to be paid[168] and, for each such amount, the date on or before which it is to be paid. Section 36(c)(i) contemplates that different amounts the subject of a determination may have different payment dates.

148 Thirdly, the effective operation of s 38 - 43 of the Act does not depend upon the adjudicator's determination operating as an organic and indivisible whole. Each of those provisions operates effectively if a determination is confined to the amount or amounts properly determined by the adjudicator to be paid, excluding any severable amount or amounts purportedly determined in excess of jurisdiction.

149 Finally, and more generally, it is an Act, according to the long title, 'to provide a means for adjudicating payment disputes arising under construction contracts'. In relation to the adjudication of 'payment disputes' the Act is plainly beneficial legislation. Adjudicators may, but need not, be legally qualified and the prospect of jurisdictional error occurring at times is perhaps unavoidable. In this context, and given the relatively short time frames under which the adjudicator must work, and the 'primary aim of keeping the money flowing down the contractual chain',[169] the Parliamentary intention to be inferred is that decisions of adjudicators, to the extent that they deal with the adjudication of a 'payment dispute', within the meaning of s 31(2)(b), are to have the fullest operation.

150 In this case, Adjudicator Loots' determination that Samsung was liable to Duro in an amount of $34,186,114.38 is plainly severable, in accordance with the principles referred to earlier, from the other amounts the subject of his determination. The invalid part of the adjudicator's determination did not influence the making of the valid part of his determination. The invalid component was not an integral or essential element of the valid component or the determination as a whole. Certiorari is available to quash the determination to the extent that the amount of $49,642,958.72 includes the amount of $34,186,114.38. An order for mandamus would be an exercise in futility given the arithmetical nature of the correction involved.

151 An order to that effect involves, at most, a 'notional interference'[170] with Adjudicator Loots' Third Determination. In any event, as Deane J observed in Re Gray; Ex parte Marsh:[171]

Mandamus and prohibition involve no intermeddling in, or assumption of, the jurisdiction of the court to which they are directed. Where certiorari encompasses the making of an order which should have been made by a court to which the writ is directed, it involves the doing of what is within that court's jurisdiction. Even in the ordinary case where certiorari is directed merely to quash, it will commonly involve an element of interference with the actual exercise of jurisdiction conferred on a court to which the writ is directed if that court is empowered to determine questions of law: eg certiorari to correct an error of law on the face of the record even though it does not go to jurisdiction. (emphasis added)

152 An order to the above effect, in substance, gives effect to Adjudicator Loots' own determination of what was in law the relevant (and only) 'payment dispute' before him.[172]

154 The set-off issue relates to what the primary judge described as the 'Second Determination', concerning the 'November NC Progress Claim'.[173] The 'Second Determination' is a determination of Adjudicator Machell on 10 February 2016.[174]

155 In these reasons we refer to the 'November NC Progress Claim' as the 'November NC Claim' for greater ease of differentiation from what the primary judge described as the 'Main November Progress Claim'.[175]

156 We agree with the Chief Justice, generally for the reasons he gives, that the primary judge erred in finding that Adjudicator Machell exceeded his jurisdiction in finding that Samsung was not entitled to set off, as against the amounts claimed by Duro in the November NC Claim, an amount in respect of an advance payment of $6.66 million. We would also make the following specific observations on this aspect of the appeal.

157 For present purposes, the material facts may be summarised as follows. Prior to Duro's November NC Claim, Samsung had certified in earlier Progress Certificates that Duro was liable to pay it $64.2 million for liquidated damages.[176]

158 The sum of $64.2 million comprised two amounts. One was for $51 million arising in the month of October 2015 which remained unpaid.[177] The other was for $13.2 million which had been withheld and applied by Samsung in the past against amounts otherwise due to Duro.[178]

159 Further, Duro had a liability to Samsung for $6.66 million in respect of a payment in advance on account.[179]

The adjudicator's decision and Samsung's challenge

160 In the 'Second Determination' Adjudicator Machell found, in effect, the following:

1. Samsung is prima facie entitled to set off an amount of $6.66 million in respect of an advance payment made on account, against any money otherwise found to be due to Duro in its November NC Claim.[180]
2. Samsung has no contractual entitlement to liquidated damages under the interim contract, and Samsung has no entitlement to set off the sum of $51 million allegedly remaining outstanding for liquidated damages.[181]
3. Further, Samsung had incorrectly withheld $13.2 million for liquidated damages under previous Progress Certificates.[182]
4. Despite Samsung's prima facie entitlement, Samsung had no actual right to set off the sum of $6.66 million against Duro's November NC Claim. That was because, in effect, Samsung already owed Duro $13.2 million by reason of the wrongful set off of liquidated damages in the earlier Progress Certificates.[183]

161 Samsung alleged in the primary proceedings that by bringing to account Samsung's liability of $13.2 million (as found by the adjudicator), the adjudicator had exceeded his jurisdiction.[184]

162 The issue before the primary judge was whether Adjudicator Machell exceeded his jurisdiction under s 31(2)(b) of the Act by finding, in effect, that Samsung had no entitlement to set off the claim for $6.66 million against Duro's November NC Claim, because Duro had its own pre-existing entitlement to set off, as against its $6.66 million liability to Samsung, an amount of $13.2 million unlawfully withheld by Samsung for liquidated damages pursuant to earlier Progress Certificates.

163 The primary judge held that Adjudicator Machell's decision was affected by jurisdictional error. His Honour said:[185]

In the adjudication, Samsung claimed that it was entitled to set-off an amount for liquidated damages against amounts it owed to Duro in relation to the [November NC Claim]. The adjudicator determined that Samsung was not entitled to such a set-off. In so determining, the adjudicator was performing his statutory function under s 31(2)(b). What the adjudicator was not empowered to do was to apply his conclusion that Samsung was not entitled to a set-off for liquidated damages to Samsung's response to an earlier, separate payment claim, and then to credit Duro with the amount of that 'wrongful' set-off against Samsung's right to credit for its payment on account.

The scheme of the Act is founded on the fact that contractors under construction contracts will often make regular claims for progress payments. Generally, each progress claim will be a separate payment claim, the rejection or non-payment of which gives rise to a separate payment dispute. It is an element of the scheme of the Act that disputes in respect of each payment claim are kept separate; each dispute has its own time limit under s 26(1) and each is to be the subject of a separate adjudication, unless the parties consent under s 32(3)(b). It is not open to an adjudicator to find that the amount payable by a party in relation to the payment claim before the adjudicator is to be increased (or decreased) on the ground that the adjudicator considers that a party wrongfully denied liability (or wrongfully made a claim) in relation to an earlier, different payment claim. That is what the adjudicator did in this case.

...

For the reasons I have given, the adjudicator's statutory function under s 31(2)(b) did not empower him to bring to account an amount in favour of one party on the ground that the other party had wrongfully claimed a set-off in its response to an earlier and separate payment claim. (emphasis added)

164 In our respectful view, the primary judge erred in this regard.

165 As part of the determination under s 31(2)(b), the adjudicator was required to determine whether Samsung was entitled to set off Duro's liability of $6.66 million against the amounts claimed by Duro in the November NC Claim.

166 Even if Samsung's (asserted) entitlement to withhold $13.2 million for liquidated damages under previous Progress Certificates had not been challenged previously, all that meant was that Duro had not previously sought repayment of that money, or a credit for that money, in earlier payment claims.

167 If Samsung did not subsequently assert an entitlement to credit for other amounts, against which Samsung's (alleged) liability to Duro for having incorrectly withheld $13.2 million could be set off, then the risk to Duro for not previously challenging Samsung's retention of $13.2 million would be that Duro's cash flow would remain reduced by $13.2 million.

168 However, the Act does not, in terms or by necessary implication, preclude in these circumstances a contractor from raising an (alleged) existing liability of the principal in respect of the performance of the contractor's obligations, by way of set off, against a sum to which the principal, in response to a subsequent payment claim, alleges it is entitled to by way of a credit.

Samsung's notice of contention Ground 1

169 By ground 1 of its notice of contention, Samsung refers to findings by the primary judge to the effect that the 'Second Determination' involved the determination of claims for work which are excluded from the definition of 'construction work' by s 4(3)(c) of the Act.[186] The relevant findings relate to claims for amounts of €182,690.45 and $AUD333,119.[187]

170 Samsung contends that, even if Duro succeeds on ground 1 of the Duro Appeal, if Samsung succeeds in its appeal (ie, the Samsung Appeal), Adjudicator Machell's adjudication is affected by jurisdictional error and is void in any event.

171 Duro does not challenge the primary judge's findings referred to above. Nor does Duro contend that Adjudicator Machell's decision is severable. Given that Samsung should, in our view, succeed on ground 2 in the Samsung Appeal, we would uphold ground 1 of Samsung's notice of contention.

172 By ground 2 of its notice of contention Samsung contends that if Duro succeeds on ground 2 in Duro's Appeal as to severance, and Samsung succeeds in the Samsung Appeal, then, even if there can be severance of the kind contended for in ground 2, 'there can be no severance to deal with the extent to which the subject of the Third Determination [by Adjudicator Loots] concerned a claim for payment that included work excluded under s 4(3) of the [Act] and the court should find that the work the subject of the Third Determination included a substantial part that was not capable of giving rise to a payment claim at all'.[188]

173 The notice of contention in this regard proceeds on the assumption that Samsung succeeds on ground 1 of the Samsung Appeal, and that Adjudicator Loots was required to dismiss Duro's application for adjudication under s 31(2)(a)(ii) of the Act.[189]

174 As Samsung has not succeeded on that point in the Samsung Appeal, this aspect of the notice of contention should be dismissed.

175 The parties should be heard on the question of final orders conformable with these reasons.

The long title provides that it is (amongst other things):

• to provide a means for adjudicating payment disputes arising under construction contracts ...

determination means a determination, made on an adjudication under Part 3, of the merits of a payment dispute[.]

Section 6 defines 'payment dispute' as, relevantly:

For the purposes of this Act, a payment dispute arises if -

(a) by the time when the amount claimed in a payment claim is due to be paid under the contract, the amount has not been paid in full, or the claim has been rejected or wholly or partly disputed[.]

payment claim means a claim made under a construction contract -

(a) by the contractor to the principal for payment of an amount in relation to the performance by the contractor of its obligations under the contract[.]

The object of an adjudication of a payment dispute is to determine the dispute fairly and as quickly, informally and inexpensively as possible.

(2) An appointed adjudicator must, within the prescribed time or any extension of it made under section 32(3)(a) -

...

(b) otherwise, determine on the balance of probabilities whether any party to the payment dispute is liable to make a payment, ... and, if so, determine -

(i) the amount to be paid or returned and any interest payable on it under section 33; ...

(a) with the consent of the parties, extend the time prescribed by section 31(2) for making a determination;

(b) with the consent of the parties, adjudicate simultaneously 2 or more payment disputes between the parties;

(c) with the consent of all the parties concerned, adjudicate the payment dispute simultaneously with another payment dispute.

(4) If an appointed adjudicator adjudicates simultaneously 2 or more payment disputes, the adjudicator may, in adjudicating one, take into account information the adjudicator receives in relation to the other, and vice versa.

(1) If an appointed adjudicator determines that a party to a payment dispute is liable to make a payment, he or she may also determine that interest is to be paid -

(a) if the payment is overdue under the construction contract, on the payment in accordance with the contract; or

(b) otherwise, on the whole or a part of the payment from the date the payment dispute arose at a rate not greater than the rate prescribed under the Civil Judgments Enforcement Act 2004 section 8(1)(a),

(2) Subsection (1) does not authorise the awarding of interest upon interest.

(1) A party that is liable to pay an amount under a determination must do so on or before the date specified in the determination.

(2) Unless the determination provides otherwise, interest at the rate prescribed under the Civil Judgments Enforcement Act 2004 section 8(1)(a) is to be paid on such of the amount as is unpaid after the date specified in the determination.

(3) The interest to be paid under subsection (2) forms part of the determination.

(4) If under s 43(2) a judgment is entered in the terms of a determination, interest under subsection (2) ceases to accrue.

(1) If on the adjudication of a payment dispute the appointed adjudicator makes a determination -

(a) the adjudicator cannot subsequently amend or cancel the determination except with the consent of the parties; and

(b) a party to the dispute may not apply subsequently for an adjudication of the dispute.

(2) Despite subsection (1)(a), if an adjudicator's determination contains -

(a) an accidental slip or omission; or

(b) a material arithmetic error; or

(c) a material mistake in the description of any person, thing or matter,

the adjudicator, on the application of a party or, after notifying the parties, on the adjudicator's own initiative, may correct the determination.

1. Non-compliance by principal, contractor may suspend its obligations

(1) If a determination requires the principal to pay the contractor an amount and the principal does not pay in accordance with the determination, the contractor may give the principal notice of the contractor's intention to suspend the performance of its obligations.

(2) The notice must -

(a) be in writing; and

(b) be prepared in accordance with, and contain the information prescribed by, the regulations; and

(c) state the date on which the contractor intends to suspend the performance of its obligations; and

(d) be given to the principal at least 3 days before that date.

(3) If on the date stated under subsection (2)(c) in the notice the principal has not paid the contractor the amount in accordance with the determination, the contractor may suspend the performance of its obligations until no longer than 3 days after the date on which the amount is paid.

(4) Subsection (3) does not prevent the contractor from at any time resuming the performance of its obligations.

(5) A contractor that suspends the performance of its obligations in accordance with this section -

(a) is not liable for any loss or damage suffered by the principal or by any person claiming through the principal; and

(b) retains its rights under the contract, including any right to terminate the contract.

1. Determinations may be enforced as judgments

court of competent jurisdiction, in relation to a determination, means a court with jurisdiction to deal with a claim for the recovery of a debt of the same amount as the amount that is payable under the determination.

(2) A determination may, with the leave of a court of competent jurisdiction, be enforced in the same manner as a judgment or order of the court to the same effect, and if such leave is given, judgment may be entered in terms of the determination.

(3) For the purposes of subsection (2), a determination signed by an adjudicator and certified by the Building Commissioner as having been made by a registered adjudicator under this Part is to be taken as having been made under this Part.

I certify that the preceding paragraph(s) comprise the reasons for decision of the Supreme Court of Western Australia.

[1] For the purposes of this appeal, the applicable version of the CCA is that which preceded the amendments made in November 2016.

[2] Which relates to Mr Machell's determination.

[3] Which relates to Mr Loots' determination.

[4] Samsung C&T Corporation v Loots [2016] WASC 330 (primary reasons).

[5] There were two progress claims made by Duro with respect to November 2015 - the claim the subject of the 'Second Determination' is the later of the two.

[6] Samsung contends that, in fact, the amount of $13,171,349 was withheld against Duro's April progress claim, but nothing turns upon the identification of the particular previous claim from which this amount was deducted.

[11] Alliance Contracting Pty Ltd v James [2014] WASC 212 [60] (Alliance Contracting).

[17] Applications for adjudications must be brought within 28 days after a payment dispute arises - CCA, s 26(1).

[18] Respondent's submissions [10] - [13] (WAB 77 - 78).

[20] Put in quaint legal terms, the adjudicator only allowed Duro to use Samsung's wrongful withholding of $13.1 million as a shield to Samsung's claim to set off $6.6 million - not as a sword.

[21] Alliance Contracting [60].

[30] Part 5 of the submissions - GAB 2, 137 - 156.

[33] As required by s 31(2)(a)(iv) of the CCA.

[37] GAB 2, 221, relying upon Zurich Bay Holdings Pty Ltd v Brookfield Multiplex Engineering and Infrastructure Pty Ltd [2014] WASC 39 [22] (Le Miere J) and EC & M Pty Ltd v CTEC Pty Ltd [2013] WASAT 114 [11], [13] (Senior Member Raymond).

[42] Zurich Bay Holdings Pty Ltd v Brookfield Multiplex Engineering and Infrastructure Pty Ltd [2014] WASC 39 [22] (Le Miere J); Alliance Contracting [50] - [76] (Beech J); Cooper & Oxley Builders Pty Ltd v Steensma [2016] WASC 386 [22] (Le Miere J) (Steensma).

[43] Alliance Contracting [50] - [76] (Beech J); Steensma [21] (Le Miere J).

[46] In this case being those parts of the determination relating to the car dumper claims and the amount claimed for commissioning of a control system - together amounting to approximately $15.4 million.

[51] Alliance Contracting [84] - [91].

[52] Multiplex Constructions Pty Ltd v Luikens [2003] NSWSC 1140 [92] (Multiplex Constructions Pty Ltd), at primary reasons [417].

[53] Trysams Pty Ltd v Club Constructions (NSW) Pty Ltd [2007] NSWSC 1298 [16]; Anderson Street Banksmeadow Pty Ltd v Helcon Contracting Australia Pty Ltd [2013] NSWSC 657 [9].

[54] Thiess Pty Ltd v Warren Brothers Earthmoving Pty Ltd [2012] QSC 373 [61]; Thiess Pty Ltd v Warren Brothers Earthmoving Pty Ltd [2013] QSC 141 [28] - [29]; James Trowse Constructions Pty Ltd v ASAP Plasterers Pty Ltd [2011] QSC 145 [55].

[55] BM Alliance Coal Operations Pty Ltd v BGC Contracting Pty Ltd [2013] QCA 394; [2015] 1 Qd R 228 (BM Alliance Coal Operations Pty Ltd).

[56] With whom Holmes JA and Lyons J agreed.

[57] BM Alliance Coal Operations Pty Ltd [71].

[58] Gantley Pty Ltd v Phoenix International Group Pty Ltd [2010] VSC 106 (Gantley).

[59] Building and Construction Industry Security of Payment Act 2002 (Vic), s 10B, s 23(2A) and s 23(2B).

[61] Re Narula, Ng & Hammersley; Ex parte Atanasoski [2003] WASCA 156 (Re Narula) referred to in primary reasons at [421] - [424].

[65] Primary reasons [423] - [424].

[67] To which I have already referred - see [48] - [50] above.

[68] M+W Singapore Pte Ltd v Anstee-Brook [2016] WASC 310 (M+W Singapore Pte Ltd).

[69] M+W Singapore Pte Ltd [43].

[70] M+W Singapore Pte Ltd [44].

[71] Syntech Resources Pty Ltd v Peter Campbell Earthmoving (Aust) Pty Ltd [2011] QSC 293 [44].

[72] Maxcon Constructions Pty Ltd v Vadasz (No 2) [2017] SASCFC 2 (Maxcon).

[73] Maxcon [222] (Lovell & Hinton JJ agreeing).

[74] Although the case went on appeal to the High Court, because that Court concluded that the adjudicator had not erred, no question of severance of a partially valid award arose - see Maxcon Constructions Pty Ltd v Vadasz [2018] HCA 5.

[75] At least all those which I have been able to identify.

[76] Re Media, Entertainment & Arts Alliance; Ex parte Arnel [1994] HCA 1; (1994) 179 CLR 84 (Ex parte Arnel).

[78] Roads and Traffic Authority in New South Wales v Higginson [2011] NSWCA 151.

[79] Director of Public Prosecutions (Cth) v Ede [2014] NSWCA 282.

[80] Or, with respect, the question for determination in Maxcon.

[86] Interpretation Act 1984 (WA), s 3(1)(b).

[87] Director of Public Prosecutions (Cth) v Ede; Bros Bins Systems Pty Ltd v Industrial Relations Commission of New South Wales [2008] NSWCA 292; (2008) 74 NSWLR 257; Roads and Traffic Authority of NSW v Higginson.

[88] INPEX Operations Australia Pty Ltd v JKC Australia LNG Pty Ltd (No 2) [2017] NTSC 61.

[90] Metacorp Australia Pty Ltd v Andeco Construction Group Pty Ltd [2010] VSC 199; (2010) 30 VR 141; Maxstra Constructions Pty Ltd v Joseph Gilbert [2013] VSC 243; SSC Plenty Road v Construction Engineering (Aust) (No 2) [2015] VSC 680.

[91] Richard Crookes Construction Pty Ltd v CES Projects (Aust) Pty Ltd (No 2) [2016] NSWSC 1229 (McDougall J).

[92] Plaintiff M 79/2012 v Minister for Immigration and Citizenship [2013] HCA 24; (2013) 252 CLR 336 (Plaintiff M 79/2012).

[93] Plaintiff M 79/2012 [83]. The issue of severance was not considered by the other members of the court.

[94] Cheatley v The Queen [1972] HCA 63; (1972) 127 CLR 291, 308 - 309.

[95] Australian Securities Commission v Marlborough Goldmines Ltd [1993] HCA 15; (1993) 177 CLR 485.

[96] Maxcon and BM Alliance Coal Operations Pty Ltd.

[97] Samsung C&T Corporation v Duro Felguera Australia Pty Ltd [2018] WASCA 27.

[98] Samsung C&T Corporation v Loots [2016] WASC 330 (primary decision).

[99] Samsung C&T Corporation v Duro Felguera Australia Pty Ltd [2018] WASCA 27.

[100] Primary decision [26] - [27].

[101] Primary decision [144], [166]; GB 479.

[102] Primary decision [187] - [189], [199]. All figures in these reasons are approximate.

[103] Primary decision [205] - [228].

[104] Primary judge's orders, par 7, BB 2 - 3.

[105] Primary decision [416] - [418].

[106] Alliance Contracting Pty Ltd v James [2014] WASC 212.

[107] Multiplex Constructions Pty Ltd v Luikens [2003] NSWSC 1140.

[108] Although the legislation in other States is not the same as the Act.

[109] BM Alliance Coal Operations Pty Ltd v BGC Contracting Pty Ltd [2013] QCA 394; [2015] 1 Qd R 228.

[110] Maxcon Constructions Pty Ltd v Vadasz (No 2) [2017] SASCFC 2; (2017) 127 SASR 193.

[113] Maxcon [145] - [148], [155] - [156].

[114] See Maxcon Constructions Pty Ltd v Vadasz [2018] HCA 5.

[116] Samsung C&T Corporation v Duro Felguera Australia Pty Ltd [2018] WASCA 27.

[119] Attorney-General for the State of South Australia v Adelaide City Corporation [2013] HCA 3; (2013) 249 CLR 1 [7].

[120] Harrington v Lowe (1996) 190 CLR 311, 326.

[121] Bank of New South Wales v The Commonwealth [1948] HCA 7; (1948) 76 CLR 1, 370 - 371.

[122] See also Interpretation Act 1984 (WA), s 7.

[123] R v Commonwealth Court of Conciliation and Arbitration, Ex parte Whybrow [1910] HCA 33; (1910) 11 CLR 1, 26 - 27, 45, 54 - 55.

[127] Harrington (329, fn (50)).

[128] Owners of SS Kalibia v Wilson [1910] HCA 77; (1910) 11 CLR 689, 713.

[129] Pidoto v The State of Victoria [1943] HCA 37; (1943) 68 CLR 87, 107.

[130] Waterside Workers' Federation of Australia v J W Alexander Ltd [1918] HCA 56; (1918) 25 CLR 434, 465, 470 (Isaacs & Rich JJ).

[134] Attorney General (New South Wales) v Perpetual Trustee (Co) Ltd [1940] HCA 12; (1940) 63 CLR 209. See also Lewski v Commissioner of Taxation [2017] FCAFC 145 [122].

[135] Perpetual Trustee (226 - 227).

[136] See Re McBain; Ex parte Australian Catholic Bishops Conference [2002] HCA 16; (2002) 209 CLR 372 [276] - [277] (Hayne J).

[137] Minister for Immigration and Multicultural Affairs v Bhardwaj [2002] HCA 11; (2002) 209 CLR 597.

[139] Bhardwaj [148] - [149].

[140] Plaintiff M 79/2012 v Minister for Immigration and Citizenship [2013] HCA 24; (2013) 252 CLR 336.

[141] Plaintiff M 79/2012 [82] - [83].

[142] Acts Interpretation Act 1901 (Cth), s 46 provides, relevantly, in effect, that there are certain instruments to which the Act applies and that, if such an instrument is construed as being in excess of power, it is taken to be a valid instrument to the extent to which it is not in excess of power.

[143] Plaintiff M 79/2012 [83].

[144] Cheatley v The Queen [1972] HCA 63; (1972) 127 CLR 291.

[147] Re Skirving; Ex parte Forward (Unreported, WASC, Library No 980737, 18 December 1998).

[148] Re Narula, Ng & Hammersley; Ex parte Atanasoski [2003] WASCA 156 [49] - [51].

[150] R v Hannan; Ex parte Abbott [1986] NTSC 22; (1986) 83 FLR 177.

[152] Hannan (182); see also Anderson v Judges of the District Court of New South Wales [1992] 27 NSWLR 701, 712 - 713.

[153] Coco v The Queen [1994] HCA 15; (1994) 179 CLR 427.

[155] Re Media, Entertainment and Arts Alliance; Ex parte Arnel [1994] HCA 1; (1994) 179 CLR 84.

[158] Buzzacott v Minister for Sustainability, Environment, Water, Population and Communities [2013] FCAFC 111; (2013) 215 FCR 301 [253] - [256].

[160] Kindimindi Investments Pty Ltd v Lane Cove Council [2006] NSWCA 23.

[161] Lacey v Attorney-General for the State of Queensland [2011] HCA 10; (2011) 242 CLR 553 [43] - [44].

[162] Saeed v Minister for Immigration and Citizenship [2010] HCA 23; (2010) 241 CLR 252 [31].

[165] Interpretation Act 2004 (WA), s 10(c)

[166] Paragraph (a) of the definition of 'payment claim'.

[167] cf O'Donnell Griffin Pty Ltd v John Holland Pty Ltd [2009] WASC 19 [76] - [80].

[168] Interpretation Act 2004 (WA), s 10(c).

[170] Adopting the language of Basten JA (McColl and Simpson JJA agreeing), albeit in a different context, in Torbey Investments Corporated Pty Ltd v Ferrara [2017] NSWCA 9 [101].

[171] Re Gray; Ex parte Marsh [1985] HCA 67; (1985) 157 CLR 351, 386.

[172] cf the observations in SS Kalibia referred to in [128] above.

[173] Primary decision [23] - [25], [260] - [262].

[176] See the October Progress Certificate GB 437 and the November Progress Certificate GB 451.

[177] Primary decision [182]; GB 437.

[178] Primary decision [267]; GB 437.

[179] Primary decision [266]; GB 354.

[180] Primary decision [266]; GB 354 - 355.

[184] Primary decision [38(h)], [260], [273] - [274]. It is not contended by Samsung that as a matter of fact, the parties' submissions to the adjudicator only addressed the outstanding sum of $51 million for liquidated damages, and did not extend to the question of any liability of Samsung for the repayment of the amount of $13.2 million previously withheld.

[185] Primary decision [280], [281], [284].

[186] Samsung's amended notice of contention, pars 1, 3 - 6, WB 89 - 90.

[187] Primary decision [25], [387] - [392].

[188] Samsung's notice of contention, par 2, WB 89.

[189] Samsung's submissions, par 11, WB 91.