FUNDAMENTAL BREACH AND REPUDIATION

Published: July 24, 2026 | By: Roger Baker 9 min read

A fundamental breach of contract deprives the innocent party of substantially the whole benefit of the bargain. Even a breach of that order ends the contract only when the innocent party accepts the repudiation. In Booster Juice Inc v West Edmonton Mall Property Inc, 2019 ABCA 58 ("Booster Juice"), a landlord's unilateral relocation of a mall kiosk was a repudiatory breach, and the lease ended when the tenant accepted that repudiation through its conduct. In Cubbon Building Centre Ltd v Gabrysh, 2020 ABQB 219 ("Cubbon"), a customer's complaints about renovation workmanship fell short of the threshold, and firing the contractor cost him the full unpaid balance with no set-off.

The third decision prices the breach itself. In Ruel v Rebonne, 2023 ABCA 156 ("Ruel"), a seller who competed against the business he had just sold paid expectation damages measured by his own sales. Read together, the three cases follow a broken deal from the moment one party wants out, through the steps the law requires, to the damages a court awards at the end. This article traces that thread for Alberta businesses.

The Breach That Goes to the Root

Not every breach ends a contract. Termination is reserved for a breach so serious that it "deprives that party of substantially the whole benefit of the contract" (Booster Juice at para 13). The same threshold governs performance contracts like renovations; a fundamental breach "must be a breach that goes to the root of the contract" and deprive the innocent party "of substantially the entire benefit of the very thing for which it contracted" (Cubbon at para 89, quoting 1314058 Alberta Ltd v Albers).

Even a breach of that magnitude does not end the contract by itself. The innocent party must accept the repudiation, because "[i]f the other party accepts the repudiation, the contract is terminated, and the parties are discharged from future obligations" (Booster Juice at para 19, quoting Guarantee Co of North America v Gordon Capital Corp). Until then, "an unaccepted repudiation is a thing writ in water" (Booster Juice at para 20, quoting Chitty on Contracts). Acceptance must be clear and unequivocal, though sufficiently unequivocal conduct can do the job (Booster Juice at para 20).

Booster Juice: The Relocated Kiosk That Ended a Lease

Booster Juice had run a profitable location in Phase III of West Edmonton Mall for over a decade and leased space for a second kiosk in Phase I, with a term commencing November 1, 2013 (Booster Juice at paras 2–3). On March 19, 2014, the landlord unilaterally changed the location and directional orientation of the planned kiosk when it approved the design (at para 14). The trial judge had heard evidence that Booster Juice agreed to the original spot because it sat close enough to the main corridor to draw mall traffic, and the Court of Appeal found no error in the conclusion that the location was fundamental to the lease (at paras 16–17). Moving the kiosk deprived the tenant of substantially the whole benefit of the contract (at para 17).

Booster Juice accepted the repudiation through conduct. It did not start construction as requested, it raised the new location as a problem at a meeting, and it kept not paying rent, which by April 30, 2014 amounted to acceptance (at paras 22–23). From that date the parties were discharged from their future obligations (at para 23). When the landlord later invoked a cross-default clause in the Phase I lease to terminate the profitable Phase III location, the move failed; the rights under that clause "would have been extinguished" once the Phase I lease was already dead (at para 26).

Termination did not erase what had already accrued. Booster Juice remained liable for six months of unpaid rent, judgment going against it for $64,572, while the landlord owed $30,738 for improperly closing the Phase III location (at paras 5 and 33–34). The landlord was entitled to nothing for the unexpired term after the repudiation was accepted (at para 35). Neither side left clean.

Can a Customer Fire the Contractor and Refuse to Pay?

Not unless the defects deprive the customer of substantially the entire benefit of the bargain, and, where the problems are capable of remedy, not without first giving the contractor a real chance to fix them. Cubbon opens with the question in plain terms, "whether a home renovation contractor's workmanship is so deficient that the customer is relieved of any obligation to pay" (Cubbon at para 1). The answer, on those facts, was no.

Cubbon, a Wetaskiwin building centre, contracted to renovate a farmhouse exterior with new siding, windows, doors, and stonework (at paras 2 and 11). By early January 2016 the work was substantially complete, a point both sides agreed on (at paras 30–31 and 99). At a site meeting the customer raised his concerns, and the contractor's representative recorded a 16-item list of fixes and undertook to send the installer back to finish everything (at paras 32–34). The next day, after receiving the labour invoice, the customer fired Cubbon by telephone, and neither the contractor nor its installer was allowed back on the property (at paras 39 and 43). Months later he and his son stripped the installed work "down to the plywood" and paid a replacement contractor $56,009.78 to redo it (at para 49).

The court found no fundamental breach. The work was substantially complete, and the concerns raised were capable of remedy had Cubbon been given the chance (at paras 99–100). A customer claiming a back-charge for defective work must, among other things, have "gave notice to the subcontractor of its default and a reasonable opportunity to cure it" (at para 95, quoting Impact Painting Ltd v Man-Shield (Alta) Construction Inc); here the customer "did not afford Cubbon a reasonable or any opportunity to cure" (at para 96). The set-off was denied in full. The court called the case "an extreme case of buyer's remorse" and gave judgment for the entire unpaid balance of $77,691.76, plus interest under the Judgment Interest Act (at paras 101, 107, and 115). As for the demolition, "[t]earing something down does not mean that it was not done in the first place" (at para 102).

One more feature of Cubbon deserves attention. The customer's version of events repeatedly conflicted with the contemporaneous documents, and the court expressly preferred the witnesses whose testimony matched the paper record (at para 54). The case was largely decided by faxes, statements, and handwritten site notes created years before anyone contemplated a trial.

Ruel: Damages Measured by the Breaching Party's Own Sales

Ruel is a damages decision, about pricing a breach rather than ending a contract. In 2014, Darren Ruel bought a home décor import business called Down the Beaten Path, and the sale agreement bound the seller to a five-year non-competition clause (Ruel at paras 2–3). The seller had incorporated a company in essentially the same business, assured the buyer it would sell only into the United States, and then, after the relationship broke down in 2017, sold directly to the purchased business's Canadian customers (at para 6).

The Court of Appeal upheld both the covenant and the finding of breach. A non-competition clause in a contract for the sale of a business "is lawful unless it can be established on a balance of probabilities that its scope is unreasonable" (at para 10, citing Payette v Guay inc). The clause here was reasonably limited in activity, territory, and duration, and it protected the buyer's legitimate interest in the value of what he had purchased (at para 11).

The damages analysis is the reason the case matters to anyone weighing a breach. The trial judge measured expectation damages by totalling the invoices the seller's new company issued to Canadian customers of the purchased business, discounted for the cost of goods, arriving at $83,266.05 (at para 16). The Court of Appeal approved. "[U]sing the appellant's gains as a means of measuring the respondent's losses is entirely supportable to achieve the compensatory purpose of expectation damages" (at para 16). A $30,000 award for mental distress was reversed. The trial judge never applied the test from Fidler v Sun Life Assurance Co of Canada, which requires that an object of the contract was to secure a psychological benefit and that the suffering was serious enough to warrant compensation (at paras 19–20). Damage awards otherwise attract deference on appeal, a standard Ruel stated citing Booster Juice (at para 14).

What Ties the Three Cases Together

In each case, the party who took matters into its own hands paid for it. The landlord that moved the kiosk without agreement lost the lease, lost its cross-default rights over a second location, and took judgment against it for the closure (Booster Juice at paras 5, 17, and 26). The customer who fired his contractor and demolished the work paid the full unpaid balance with no set-off (Cubbon at paras 100 and 107). The seller who competed in the face of his own covenant watched his sales ledger become the measure of the plaintiff's damages (Ruel at para 16).

The law's sequence runs through all three decisions. Termination requires a breach that goes to the root of the contract, and acceptance of the repudiation must be clear (Booster Juice at paras 13 and 19–20). Where defective work is capable of remedy, the customer must give notice and a genuine opportunity to cure before hiring a replacement and claiming the cost (Cubbon at paras 89 and 95–96). Termination then operates forward, not backward. Obligations that accrued before acceptance survive, which is why Booster Juice paid six months of rent on a lease its landlord had repudiated (Booster Juice at paras 23 and 33–34).

The damages principles are just as consistent. Expectation damages put the innocent party where performance would have left it, and no further; the repudiating landlord recovered nothing for the unexpired term after acceptance in Booster Juice, the customer got no set-off without a cure opportunity in Cubbon, and no mental distress award survived in Ruel without the findings Fidler requires (Booster Juice at para 35; Cubbon at paras 96 and 107; Ruel at paras 16 and 19–20). Findings of fact are reviewed only for palpable and overriding error, and damage awards only for errors of principle (Booster Juice at paras 8 and 10; Ruel at paras 13–14). On those standards, the findings made at trial, on records built while the deal was collapsing, are difficult to dislodge.

What This Means for Alberta Businesses

The moment a contract starts to fail is the moment the eventual judgment starts being written. The documents created in that window, quotes, statements, site notes, and correspondence, decided Cubbon, and conduct in that window fixed the termination date and the rent liability in Booster Juice (Cubbon at para 54; Booster Juice at paras 22–23). A business weighing termination faces the threshold question of whether the breach strips substantially the whole benefit of the contract, and an error in that judgment reverses the parties' positions.

The remedies follow the bargain rather than the grievance. A party deprived of its deal recovers what performance would have brought, in Ruel the breaching seller's net profit from the offending sales, together with interest under Alberta's Judgment Interest Act (Ruel at para 16; Cubbon at para 115). The prescribed rates under that Act are the ones behind the firm's judgment interest calculator. Heads of damages beyond the bargain, like mental distress, require their own legal foundation (Ruel at paras 19–20).