Executive Summary: Key Legal and Evidentiary Issues

• Characterization of the renovation contract beyond the written purchase order as a contract on estimate rather than a lump-sum (forfait) agreement, and the legal consequences for pricing and extras.
• Weight given to the insurer’s detailed “Devis” as a financial parameter or budget, rather than a line-by-line binding price list for the contractor.
• Sufficiency and reliability of Construction Zanetti’s invoices and supporting documentation, including the rejection of certain “travaux divers reportés” and adjustment of credits for unperformed items.
• Evaluation of evidence on cash and cheque payments made during the project, and reconciliation of total amounts billed versus actually paid by the owner.
• Analysis of the owner’s reconventional claim of overpayment and alleged “surfacturation” through the lens of répétition de l’indu, including the requirement of payment made in error.
• Consideration of the owner’s sophistication, prior renovation experience, and contemporaneous conduct (paying invoices without protest) as key evidentiary factors defeating the overpayment claim.

Facts of the case

The case arises from a major fire in November 2019 that seriously damaged the residence of Isabelle Poulin De Courval in Montréal. The fire started near the furnace in the basement, causing carbonization of part of the roof, certain floors and sections of exterior walls, and leaving various walls and floors affected by smoke and water. Desjardins Groupe d’assurances générales inc., her property insurer, inspected the property several times and produced a detailed “Devis” in December 2019, running over 80 pages, listing the rebuilding and renovation work required to return the home to its pre-loss condition, room by room and by major trade (electricity, ventilation, etc.). The Devis was prepared on an “as was” basis, meaning it contemplated reconstruction to identical standards and configuration, without upgrades or changes, and it expressly excluded certain categories of costs such as demolition, winter conditions, professional fees, permits, code upgrades and CNESST-related charges. The total value of work under this Devis, including the contractor’s administration and profit, was set at 346 425,52 $ taxes in, and Desjardins fixed the insured’s indemnity accordingly, with the owner keenly aware of these parameters due to her own recent experience renovating the same residence.
Before the end of 2019, Ms. De Courval advised Desjardins that she wished to use her own contractor and to act, in substance, as her own “project manager” on site. In early 2020 she contacted Construction Daniel V. Zanetti inc. Initially, she retained this contractor for the most urgent work: reconstruction of the roof and removal of fire-damaged structural components. These urgent items were captured in a written “Bon de commande” in March 2020, which both parties accepted as a lump-sum (forfait) construction contract in the amount of 69 670 $ plus taxes (80 103,08 $).
As the project developed, Ms. De Courval decided to entrust Construction Zanetti with almost all of the remaining work listed in the insurer’s Devis, with the goal of accelerating progress so she could reoccupy her home by July 2020. She nonetheless retained control over certain aspects: she would purchase some materials herself and hire separate trades for specific tasks, such as the basement. At the same time, she saw the rebuild as an opportunity to modify and improve the house, planning numerous changes and additions to the strictly “as was” scope described in the Devis.

The contractual structure and scope of work

Two distinct construction contracts governed the relationship. The first was the written Bon de commande for the urgent roof and structural works, clearly framed and accepted as a lump-sum (forfait) agreement. The second, more controversial, covered the remainder of the renovations not included in that purchase order. No written contract was signed for this broader renovation work, and the parties disagreed profoundly on its legal nature.
Construction Zanetti maintained that the second contract was, in effect, a contract on estimate with a financial “ceiling” or budget set by the Devis, but without any obligation to follow each Devis line item price to the dollar. In its view, the Devis served as a guide—reflecting the homeowner’s available insurance indemnity and budget—while allowing for flexibility in executing and pricing the actual work, especially given the numerous variations requested.
By contrast, Ms. De Courval argued that the second contract was a strict contract “sur estimation” in which Construction Zanetti was bound to respect each detailed price in the insurer’s Devis line by line. She claimed the contractor was only permitted to deviate from these specified amounts in the limited situations allowed by the Civil Code for contracts on estimate, essentially where unforeseen work (force majeure-like circumstances) justified an increase.
The Court reviewed the Civil Code’s framework for contracts of enterprise (articles 2098 and following), distinguishing among three main types: contracts on estimate (article 2107 C.c.Q.), cost-plus contracts (article 2108 C.c.Q.), and lump-sum (forfait) agreements (article 2109 C.c.Q.). It emphasized that the characterization turns on how the price is determined and the degree of precision with which the parties have described the work and assigned risk. Especially in renovation contexts, where conditions are uncertain, courts are cautious about treating loosely defined verbal understandings as fixed-price forfait contracts.
Here, the judge found the verbal agreement for the non-roof work to be ambiguous and turned to the surrounding circumstances and the parties’ conduct. Evidence showed that when Ms. De Courval asked Construction Zanetti to take on all the remaining renovation work, the contractor initially told her it would need to stop and prepare a detailed written quote. She declined, insisting on urgency so she could move back in by the end of July and avoid delays related to mortgage renewal and displacement. At the same time, contemporaneous emails revealed that both sides increasingly spoke in terms of a “budget” drawn from the insurer’s Devis, and Construction Zanetti repeatedly referenced “les coûts et paramètres de votre assureur Desjardins Assurances” when sending invoices.
The Court held that this language, combined with the homeowner’s explicit calculation of her remaining “budget” from insurance and her expressed need to “manage the expenses,” showed the parties intended to keep the total cost within or below the insured indemnity, but not to freeze every line item of the Devis as a binding tariff. Thus, it concluded that the second contract was indeed a contract on estimate, with the Devis acting as a budgetary framework or benchmark rather than a rigid pricing schedule for each task.

Execution of the work and changes requested

From March to September 2020, subject to the temporary COVID-19 work stoppage, Construction Zanetti carried out the roof and structural repairs under the forfait Bon de commande, as well as most of the additional renovation work contemplated in the Devis. As the work progressed, Ms. De Courval requested many modifications and extras that went beyond the insurer’s original “same as before” specification. Evidence accepted as credible showed that she requested, among others, the following: correction of prior construction defects and restructuring of walls; levelling of the ground-floor floor system; adjustments to window openings; modifications to interior partitions and the vestibule; alteration of a wall to accommodate a two-sided fireplace; widening of a brick-wall opening; three separate rounds of changes to plumbing and removal of a shower; closing off a non-functional chimney; work related to the backyard shed; changes to the electrical service entrance; remedial cleaning of work previously done by another contractor (Groupe Dijon); and removal of basement insulation.
The Court found that these changes were authorized verbally by the homeowner, executed accordingly, and then billed without contemporaneous objection. The contractor issued multiple invoices during the project, some relating to the forfait contract (with lump-sum entries) and others detailing hours, materials and categories of work. By the time the project was substantially complete, Construction Zanetti had invoiced a total of 232 365,71 $, while the insurer’s Devis had initially set the global anticipated cost at 346 425,52 $. Apart from two invoices dated October 2020, Ms. De Courval paid every invoice as it came due.

Billing, payments and the disputed balance

The main claim by Construction Zanetti centered on two unpaid invoices from October 2020: the final invoice no. 2101062 for 37 679,45 $ (covering a mix of items under both the written purchase order and the broader estimate-based contract, including certain credits and “travaux divers reportés”) and invoice no. 2001076 for 1 419,54 $ relating to a container requested by the homeowner for landscaping or exterior work.
The Court carefully analyzed the components of the final invoice. It disallowed 4 681,65 $ of “travaux divers reportés” because the supporting Excel calculation was opaque, failed to explain why those items did not appear earlier in the invoicing, and appeared partly to be a late attempt to charge an additional 18 000 $ “portion structure amorti sur estimation” over and above the fixed price of the Bon de commande without adequate evidence or accounting. The judge held that Construction Zanetti had not met its burden of proof on these amounts and ordered them removed from the final bill.
The invoice also included a credit for gutter work (765 $) that had been foreseen in the purchase order but ultimately performed by a third party after Construction Zanetti did not install them. The Court ruled that this credit was insufficient and instead used the actual third-party invoice for the gutter work (3 892 $) as the most reliable indicator of the value of the unperformed portion of the forfait. That larger amount was subtracted from the contractor’s claim.
Conversely, a credit of 1 200 $ for recessed light fixtures (40 $ per 30 fixtures) was upheld. In that instance, Ms. De Courval had supplied the fixtures herself, and Construction Zanetti only installed them. The Court noted that the contractor had previously billed 140 $ for supply and installation of 30 recessed fixtures on another invoice paid without protest, supporting the reasonableness of the credit rather than any need for adjustment.
After these corrections, the Court fixed the revised total for the October 12, 2020 final invoice at 28 701,45 $ taxes included. It further found that the container invoice for 1 419,54 $ was valid and payable because the homeowner had indeed requested the container, even if a third party ultimately completed the landscaping work.

Reconciliation of accounts and calculation of the amount owing

The Court then turned to the full payment history. The parties agreed that there had been cash payments, notably 20 000 $ in March 2020, as well as payments by cheque, but they disagreed on how these were applied and whether invoices had been implicitly reduced to account for them. Construction Zanetti argued that some invoices were “underbilled” relative to actual costs in order to reflect cash payments received off-invoice, yet it provided no coherent documentary accounting or invoice annotations to substantiate such adjustments. The judge held that the contractor could not rely on undocumented internal calculations that did not appear on the face of the invoices and that nothing in the records clearly demonstrated systematic reductions tied to the cash payments.
By contrast, the Court found that the homeowner’s evidence of payments, both cheques and recognized cash amounts, was more precise and supported by bank and accounting records. It accepted that Ms. De Courval paid a total of 214 768,22 $ during the project. After deducting the disallowed or corrected items from the contractor’s billings, the Court determined that the total legitimate amount billed for the project should be 223 387,71 $. The difference between this adjusted total and the amount already paid yielded a remaining balance owing by the homeowner of 8 619,49 $. This sum was therefore ordered payable to Construction Zanetti, with legal interest and the additional indemnity under article 1619 C.c.Q. from January 27, 2021, ten days after the receipt of the contractor’s formal demand.

The reconventional claim for overpayment and alleged overbilling

In her counterclaim, Ms. De Courval sought 83 359 $ in reimbursement, alleging that she had been overcharged significantly (surfacturation). Her theory hinged on the assertion that Construction Zanetti was legally bound to replicate exactly the Devis pricing for every line item relating to work outside the Bon de commande. To support this, she had an expert analyze the invoices against the Devis; the expert concluded that the value of the work performed by Construction Zanetti was 131 409,22 $, far less than the 214 768,22 $ she had paid. The homeowner thus claimed the difference as overpayment.
The Court reframed this claim as one in répétition de l’indu, i.e., recovery of payments that were not truly owed. Under articles 1554 and 1491 C.c.Q., three cumulative conditions must be present to succeed in such an action: (1) a payment must have been made; (2) there must be no underlying debt; and (3) the payment must have been made by error on the part of the payer. While the existence of payments was undisputed, and even if one assumed some portion of the invoiced work might be debatable, the Court focused on the third requirement and found it clearly lacking.
Far from being an uninformed consumer, Ms. De Courval worked in finance, had just previously overseen major renovations at the same property, and had already experienced prior contractor litigation. She had actively negotiated the Devis with Desjardins and was fully aware of construction pricing. She was present at the worksite, monitored the progress, and by her own admission wanted a “much closer eye” on the works precisely because of her past experience. She received and paid nine invoices over approximately six months, totaling more than what she would later claim was the entire value of all work performed. At no point did she protest the amounts, pay under reserve, or demand a line-by-line reconciliation with the Devis while the project was ongoing.
The Court underscored that she benefitted from the uninterrupted continuation of the works, enabling her to move back into her home earlier. There was no evidence that Construction Zanetti performed unauthorized work; rather, the extras and configuration changes were requested by her, often verbally, and she accepted the cost consequences at the time. Her later complaint of confusion over the invoices was undermined by her own detailed nine-page reconciliation sent in response to the contractor’s demand letter, showing that she was capable of tracking and understanding the invoicing.
On this record, the judge concluded that her payments were not made in error but were conscious, deliberate disbursements aligned with the contractual relationship and the benefits she received. Since the “error” element of réception de l’indu was not met, her reconventional claim for 83 359 $ had to be dismissed, regardless of any theoretical dispute about the exact valuation of individual tasks compared with the Devis.

Role of the insurer’s Devis and policy-related aspects

While Desjardins was not a party to the litigation, its detailed Devis and the insurance indemnity framework were central to the factual and contractual background. The Devis functioned as a comprehensive description of the repair and reconstruction work needed after the fire, with quantified allowances for each trade and component. It did not operate as an insurance “clause” enforced between the litigants, but rather as a budgetary and technical reference point. The Court accepted that the parties intended the total cost of the renovation project to be at or below the indemnity derived from the Devis, and it recognized that the homeowner’s financial planning and need to “manage expenses” were built around that insurance-funded budget. However, the judge expressly rejected the notion that the Devis imposed a binding tariff on the contractor for every line item. Instead, it served as a guide compatible with a contract on estimate, under which increases in price must be justified when they relate to unforeseen or additional work, but are not mechanically tied to each number printed in the insurer’s schedule.

Outcome and final orders

Ultimately, the Court of Québec partially allowed Construction Daniel V. Zanetti inc.’s main action. It determined that, after removing inadequately supported charges and properly valuing unperformed gutter work that had been credited too modestly, the legitimate total for the project still exceeded the amount paid by the homeowner. The Court therefore ordered Ms. Isabelle Poulin De Courval to pay a remaining balance of 8 619,49 $ to Construction Daniel V. Zanetti inc., together with legal interest and the additional indemnity under article 1619 C.c.Q. from January 27, 2021, and awarded costs of justice in the contractor’s favour. The exact total monetary impact of interest, indemnity and taxed costs cannot be determined from the judgment itself, as those amounts depend on subsequent calculation and taxation.