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A Subcontractor Recovers Against The Owner In Unjust Enrichment

A subcontractor who fails to register a construction lien faces an uphill battle in asserting a claim in unjust enrichment against the owner. That is because the owner will rely upon its contract with the contractor for any benefit that the owner has obtained from the subcontractor’s work. The owner will also assert that there is no equitable reason to grant an unjust enrichment remedy to a subcontractor who could have asserted a construction lien remedy but failed to do so.

Sometimes, however, the subcontractor’s unjust enrichment claim fits within the narrow opening between the owner’s contractual and construction lien defences, and N.K.P. Painting Inc. v. Boyko 2016 CarswellOnt 7332, 2016 ONSC 3016 was such a claim.


The owner contracted with the prime contractor for the refurbishment of the corridors of the building. The prime contractor retained NKP as the subcontractor to supply painting and wallpapering material. During the project, the owner issued progress payments to the general contractor, less the applicable statutory holdback. NKP completed its work and invoiced the prime contractor. A total of $28,928.00 was not paid by the prime contractor to NKP, and the prime contractor became insolvent. Neither NKP nor the prime contractor registered liens. The owner held back a total of $23,893.74 under the prime contract.


The Superior Court judge held that there “is no reason to deny the appellant access to the common law remedy of unjust enrichment because it did not avail itself of potential statutory remedies,” as long as the ingredients of the unjust enrichment remedy were satisfied.

The court found that the owner had retained the 10 percent holdback, and that there was no claim against that holdback for deficiencies. While there was evidence of a claim by another subcontractor, there was no evidence about the status or disposition of that claim and no evidence to suggest that anything other than the full amount of the holdback remained available and under the control of the owner.

The court therefore concluded that “it would appear clear that [the owner] has been enriched in the sense that it has received 100% of the benefit of the invoiced renovation work performed but has only paid 90% of the invoiced amounts” and that “the enrichment corresponds to the efforts of NKP through the renovation work performed for which it has received no compensation.”

The court then considered the third element in the claim for unjust enrichment, namely whether there was a juristic reason for the benefit and corresponding deprivation. While that juristic reason may be a contract, that reason could only apply:

“where the party advancing the claim for unjust enrichment is a party to the contract, as is the party against whom the claim is advanced. On the facts of the case before me, that would require a contract between NKP and [the owner]. There is no such contract. In other words [the owner’s] enrichment and NKP’s deprivation did not arise in the context of a contract between these two parties…I therefore conclude that there is no established category of juristic reason to deny recovery to the Appellant.”

The court then considered the reasonable expectations of the parties and public policy and found that neither factor should deprive NKP from a remedy in unjust enrichment:

“In my view it cannot have been within the reasonable expectation of the parties that [the owner] would receive a 100% benefit of renovation work invoiced, including NKP’s efforts, while paying only 90% of the cost of those efforts. [The owner’s] statutory obligation to retain the holdback has expired and had expired at the time of trial. There was no legal requirement at trial for [the owner] to retain the funds by way of holdback, nor did [the owner] retain any legal entitlement to those funds….The purpose of the holdback funds is to represent a potential source of funds from which to compensate unpaid providers of service and materials to the improvement of a property. It is remedial in nature….Thus [the owner] could not reasonably have expected to retain the funds and indeed were it to do so it would represent a windfall.”

The court held that the owner’s enrichment was the amount of the holdback held by the owner, and granted judgment for that amount in unjust enrichment in favour of the subcontractor.


The court arrived at a fair result but, it is submitted, the court’s conclusion is incorrect that a contract must be between the claimant and the defendant before it can be a defence to a claim in unjust enrichment.

There are many cases in which a contract has been held to be a defence to an unjust enrichment claim even though the contract was not between the unjust enrichment claimant and defendant. In most cases, the contract was between the defendant and a third party. For example, if an owner enters into a prime contract with a contractor and pays the contractor in full, including the holdback, then that prime contract is a juristic reason why the owner should not have to pay the subcontractor, which has been unpaid by the contractor but has not filed a construction lien. Requiring the owner to pay twice is not fair, either from a contract or construction lien perspective.

There are even some cases in which the contract between the claimant and a third party has been held to be a juristic reason for the claimant being denied an unjust enrichment remedy against the defendant. For example, a subcontractor has been denied an unjust enrichment remedy against an owner due to the subcontract between the subcontractor and contractor. However, unless the claimant has been paid in full under the subcontract, it is harder to justify that conclusion since there seems to be no good reason why the owner should be entitled to rely upon a subcontract to which it is not a party as a juristic reason for not paying the unpaid subcontractor.

However, the present case fits within the crack between the owner’s juristic reason defences, both based upon its prime contract with the contractor and upon the construction lien regime. The work under the prime contract had been entirely completed but the owner had not paid out the holdback under that contract. So there was no juristic reason under that contract why it should not be compelled to pay the holdback to the subcontractor.

And under section 8 of the Construction Lien Act, the holdback was held in trust “for the benefit of subcontractors and other persons who have supplied services or materials to the improvement who are owed amounts by the contractor…”. Therefore, even though the subcontractor had not filed a lien, there was a good juristic reason why the owner should pay to the subcontractor the monies in its hands that were due under the prime contract.

The validity of the subcontractor’s unjust enrichment claim extended to the amount held back by the owner, not the amount which the subcontractor had not been paid by the contractor. Payment of the former amount did not penalize the owner under the prime contract nor over-stretch the statutory trust fund remedies, while payment of the latter amount would have.

Another fact to note in this case is that the prime contractor’s trustee in bankruptcy did not assert a claim to the holdback. Accordingly, whether such a claim could have been asserted, in view of the trust fund provisions of the Construction Lien Act, was not considered.        

See Heintzman and Goldsmith on Canadian Building Contracts, 5th ed., chapter 10, part 4.

N.K.P. Painting Inc. v. Boyko 2016 CarswellOnt 7332, 2016 ONSC 3016

Building contracts – construction and builders’ liens – unjust enrichment – juristic reason defence

Thomas G. Heintzman O.C., Q.C., LL.D. (Hon.), FCIArb                                   August 20, 2017