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Ontario Court Of Appeal Holds That The Doctrine Of Mistake Does Not Apply To A Tender

In Asco Construction Ltd. v. Epoxy Solutions Inc., the Ontario Court of Appeal recently held that the doctrine of mistake did not apply to an invitation to tender. In doing so, the court provided a useful reminder of the limited circumstances in which the law of mistake can apply to building contracts.


Asco was hired by the City of Kingston to renovate a theatre. Epoxy was the successful bidder for the subcontract work to install flooring. Epoxy’s bid was based on a sketch provided by Asco during the tender process. The sketch depicted the elevations of the theatre. After the bid was accepted, but before commencing its work, Epoxy’s surveyor found that the elevations in the survey were inaccurate. Epoxy asked for an increase in the contract price which Asco refused, insisting that the work be done in accordance with the contract and that any adjustment to the price could be made later. Epoxy refused to do the work without an assurance that the contract price would be adjusted. Asco sued for breach of contract and damages and Epoxy counter-claimed for loss of profits.

The trial judge found that the error in elevation was the contractor’s fault and awarded damages in favour of Epoxy. On appeal, the Divisional Court found that the contract between the parties was void for mistake. Epoxy appealed to the Court of Appeal.

Decision of the Ontario Court of Appeal

For three reasons, the Ontario Court of Appeal held that the doctrine of mistake could not apply.

First, the trial judge had held the mistake was the fault of Asco. The Court of Appeal held that a “party at fault cannot rely on its own mistake to avoid a contract.” Accordingly, the doctrine of mistake could not apply.

Second, Asco’s tender documents represented “an implied representation to compliant bidders that the work described in the tender documents could be built as described. Those bidders are entitled to rely upon the accuracy of design information prepared by the owner or its engineers. A bidder does not have to duplicate design and analysis prior to submitting a bid.” In arriving at this conclusion, the court relied upon the decision of the Supreme Court of Canada in Edgeworth Construction Ltd. v. N.D. Lea & Associates Ltd., [1993] 3 S.C.R. 206.

Third, Asco could not rely on the doctrine of mistake because, “by asserting its claim for damages against [Epoxy], [Asco] elected to affirm the contract and thereby disentitle itself from relying on the doctrine of common mistake.”


This decision re-affirms the narrow application – or perhaps inapplicability – of the doctrine of mistake to the tender process. When a contract is made through an invitation to tender, it is only in very unusual circumstances that one party can assert to the other that it was mistaken about the contract. The parties have explicitly stated the basis of the contract, in either the invitation to tender or the response (being the bid) to that invitation. In those circumstances, the existence of a mistake seems very improbable. Either the tender and the bid have made the resultant contract clear. Or one of the parties is responsible for any mistake. In either event, the contractual doctrine of mistake cannot apply. Any difficulties in interpreting the invitation and the bid do not mean that the doctrine of mistake applies.

However, the Court of Appeal’s second proposition – that the invitation to tender contains an implied statement that the work can be built in accordance with the tender documents – seems more problematic. The Supreme Court of Canada stated that proposition in Edgeworth Construction, but where does that principle come from, and what is its ambit? The traditional rule is that an owner does not represent that a work can be built in accordance with its proposal and that a contractor takes on the “buildability” risk and must itself determine that the work can be built in accordance with its bid. Does the use of the tender process eliminate that traditional rule?

The decision in Asco v. Epoxy may reflect a general proposition that tendered contracts contain a representation that the project can be built as described in the invitation to tender. If it does, then it represents a wake-up call for owners and contractors issuing those invitations, and the consultants preparing the plans and specifications used in those invitations. They may wish to insert a specific warning into the invitation to tender that there is no representation that the building can be built as shown in the attached plans and specifications, and that it is up to the tendering contractor or subcontractor to determine that issue. If there is no such warning then the result in Asco v. Epoxy may well apply.

Asco Construction Ltd. v. Epoxy Solutions Inc., 2014 CarswellOnt 9200, 2014 ONCA 535, 242 A.C.W.S. (3d) 76

Building Contracts – Tenders – Subcontracts – Implied Representations and Conditions

Thomas G. Heintzman O.C., Q.C., FCIArb                                           September 14, 2014