Executive Summary: Key Legal and Evidentiary Issues

• Responsibility of GHD Consultants ltée for failing to respect geotechnical “rules of art” regarding the number and placement of boreholes within the footprint of the planned building extension.
• Adequacy of the geotechnical investigations and whether a properly designed campaign would likely have revealed a deeper layer of fill and prevented the unexpected surexcavation volume.
• Significance of multiple errors and omissions in the geotechnical reports (including mis-stated block sizes and missing field observations) and whether these constituted professional faults.
• Causation analysis distinguishing between faults in soil characterization and the independent decision of the excavation subcontractor to use a disposal site that was ineligible under the very data in the report.
• Proper quantification of damages attributable specifically to GHD’s faults, including only the portion of extra excavation costs and limited delay days reasonably caused by the underestimated depth of fill.
• Allocation of interest, legal costs and expert fees to the partially successful plaintiff despite only a fraction of the claimed amount being awarded.

Background and parties

Collège André-Grasset (1973) inc. is a non-profit postsecondary institution in Montréal. It decided to expand and modernise its 1976-era sports complex, a project partly funded (about 55%) by the Québec government, with the balance coming from tuition, rentals and investments. To manage the project, the College engaged engineer Marcel Bourgault as project manager and retained several professional firms, including MLC associés inc. for structural engineering and GHD Consultants ltée for geotechnical services. GHD is a consulting firm offering, among other things, engineering advisory services. The core dispute arises from alleged professional faults in GHD’s geotechnical work and the financial consequences of those faults during construction.

Geotechnical mandates and studies

In November 2018, GHD submitted its first professional services proposal to the College. It called for four stratigraphic boreholes to 6 metres and two exploratory trenches to expose the existing foundations, followed by a geotechnical report with recommendations on foundation design, granular sub-bases, groundwater control, excavation slopes and temporary support. This initial study, completed 29 January 2019, was based on an expansion footprint to the north and west of the existing sports complex. The four boreholes were located within that then-proposed footprint, while two trenches (TR-01 and TR-02) were used to partially expose foundations.

As the work progressed, the physical foundations uncovered by the trenches did not match the College’s “as-built” plans. MLC therefore requested additional trenches, and the College modified the planned expansion so that it would now extend mainly to the west and south, with a small portion to the east. This required a second GHD mandate. In February 2019, GHD proposed three more trenches and two additional boreholes. The new trenches (TR-03, TR-04, TR-05) were dug along the south and west façades, while boreholes F-05 and F-06 were drilled south of the existing building but, crucially, outside the revised footprint of the future extension.

Persistent uncertainty about the foundations led to a third GHD proposal in April 2019, aimed at further drilling to check for possible piles under the building. The resulting third and final geotechnical report, dated 9 May 2019, incorporated the earlier two reports. It included a stratigraphic summary indicating that heterogeneous fill to be excavated ranged from about 2.24 m to 4.6 m thick, with the greatest thickness at F-05 and the next largest at F-06—both outside the actual footprint of the planned southern expansion. Since the fill had to be removed down to natural soil, these depth estimates were central for contractors and subcontractors in pricing excavation quantities. The College accepted this third report and transmitted it to MLC for incorporation into the tender documents.

Tender process and construction contract

In July 2019, the College launched a call for tenders for the expansion and modernisation of the sports complex. The third GHD report formed part of the plans and specifications provided to bidders and their subcontractors. The general contractor Les Constructions Lavacon inc. submitted the lowest bid and was awarded the contract, although even its price exceeded the College’s budget, forcing the College to remove some work items from the project.

Work mobilisation on site began in October 2019, with provisional acceptance planned for 18 August 2020 and final acceptance for 17 September 2020. The College considered these dates important so that the upgraded facility would be available for students and the public at the August 2020 school term. Shortly after work began, the College also accepted a further GHD mandate, this time for quality control and verification of materials during construction, including on-call site visits for inspections, sampling and supervision.

Emergence of excavation and soil disposal problems

Almost immediately during excavation, Lavacon and its excavation subcontractor, Excavation Uni-Val, raised concerns about the size and quantity of rocks and blocks in the excavated material compared with what GHD’s geotechnical report suggested. By mid-November 2019, parts of the work were suspended. Uni-Val’s originally selected disposal site, the Complexe environnemental St-Michel in Montréal, refused to accept the excavated material. The refusal was said to be linked to a higher proportion of cobbles and larger rock blocks than indicated in the reports.

The St-Michel site is governed by strict acceptance criteria, including limits on the proportion and maximum diameter of rock blocks, overall gravel percentage, and a prohibition on debris of construction materials or industrial residues such as scories and asphalt. Uni-Val and Lavacon had relied on GHD’s geotechnical data in submitting these materials to St-Michel. When the site rejected the trucks, the project faced delays and additional transportation and disposal costs while a new site near Laval was identified.

Separately, the contractors encountered much deeper fill than anticipated in the southern portion of the enlargement footprint. While GHD’s data suggested natural soil at depths up to around 4.6 m (at off-footprint borehole F-05), the natural soil in a substantial zone within the actual footprint lay at depths exceeding 5 m. This meant a significantly greater volume of fill to excavate, more truckloads and disposal costs, and a longer excavation phase.

By August 2020, Lavacon issued a formal notice of dispute to the College under the contract, claiming approximately $472,727.54 plus taxes for extra work and prolongation of the site, a figure that later grew to over $1.43 million in combined claims. While the College negotiated with Lavacon, it also sought GHD’s views. GHD denied responsibility and advised the College to resist Lavacon’s claims, arguing that the conditions did not represent contractual “extra work” and that any errors in the reports, such as typographical mistakes, were not causative of the damages.

Independent expert review and breakdown in relations

Faced with conflicting positions between its engineer consultant and its contractor, the College commissioned an independent geotechnical review from SCP Geotek inc. That firm reported in May 2020 that a higher number of boreholes should have been drilled within the actual footprint of the expansion to achieve a reliable picture of soil conditions. It concluded that GHD’s campaign did not meet the profession’s recognized standards. After this opinion was tabled, trust between the College and GHD collapsed. Certain GHD invoices remained unpaid, GHD refused further services, and SCP Geotek took over the remaining geotechnical tasks.

In December 2020, the College formally placed GHD in default, indicating that part of Lavacon’s growing claim resulted from GHD’s faulty studies and seeking $407,845 from GHD. The College later settled its disputes with Lavacon in January 2021 by agreeing to pay $975,000 out of a total claim of $1,435,744, then scaled back its claim against GHD to roughly $308,147 (taxes included), later adjusted at trial to $306,641.

Key legal framework and professional standards

The case turned on Quebec civil law rules governing contracts for services and professional liability. Article 2100 of the Civil Code of Québec requires service providers to act according to the “rules of art” and applicable usages. Legal commentary cited by the court describes compliance with the rules of art as an obligation of result and of public order, flowing from article 1434 C.c.Q. The court also drew on the Canadian Foundation Engineering Manual as the leading technical reference in the field.

Both the College’s expert (engineer Paul-Olivier Paquet) and GHD’s own expert (engineer Claude Gou) acknowledged that, under this manual, a geotechnical reconnaissance campaign for this type of project should typically provide at least one borehole for every 500 square metres of building footprint, and that boreholes must be located within the projected construction footprint rather than outside it. The College’s extension covered about 1,800 square metres; on this basis, at least four boreholes should have been located inside the future building footprint, and particular care was expected in the southern sector where deeper fill was eventually encountered.

Alleged faults: number and placement of boreholes and trenches

GHD in fact carried out six boreholes, but only three lay within the extension footprint. Crucially, no borehole at all was drilled within the southern half of the new footprint, where the over-deep fill later caused overruns. Boreholes F-05 and F-06, which recorded the thickest fill, lay several metres south of the footprint, despite there being no physical obstacles preventing in-footprint drilling. GHD’s principal engineer, Louis Maure, conceded that the southern boreholes could have been placed in more appropriate locations, and GHD’s own expert, Gou, admitted he would have positioned F-05 and F-06 within the footprint had he been in charge.

The court held that, by not respecting the profession’s own geotechnical standards on borehole density and siting, GHD breached its duty under article 2100 C.c.Q. to comply with the rules of art. The failure to drill in the southern footprint meant that the unusually deep fill in the “surexcavation” zone was not identified in the reports. This omission, in the court’s view, misled the users of the report—MLC, Lavacon and Uni-Val—regarding the true quantity of soil to be excavated.

GHD argued that its mandate was narrower, supposedly limited to (1) determining geotechnical conditions for foundation design and (2) determining the configuration of existing foundation walls. The judge rejected this ex post facto limitation, noting that no such narrowing appeared in the offers of services or had been agreed to by the College. Even if the mandate were limited, the court said, that would not excuse contravention of the rules of art or the misleading nature of the final report.

Causation: deeper fill and increased excavation quantity

The court then asked, on the balance of probabilities, what would likely have happened had GHD located at least one additional borehole properly in the southern footprint. GHD insisted it could not be certain that such a borehole would have intersected the deep fill zone. The judge emphasised that civil causation does not require certainty, only probability. Given that the surexcavation zone represented more than half the southern excavation area, it was probable that a correctly sited additional borehole would have hit the deeper fill and alerted users to the larger volume of material.

GHD’s own expert acknowledged that, had a borehole been drilled in the surexcavation zone, it would have shown that a much greater depth of fill needed to be removed. The court accordingly found a causal link between the inadequate borehole layout and a portion of the extra excavation costs and associated delay.

Errors and omissions in the geotechnical reports

A second class of alleged faults concerned the quality and accuracy of the written geotechnical reports. The court examined hand-completed field logs from GHD’s technicians against the official transcribed trench and borehole logs annexed to the final report. Several discrepancies emerged:

• For trench TR-01, the field log recorded a block with a 2.1-metre diameter representing 25% of the excavated volume, as well as percentages of wood debris, bricks, cobbles and a drain; none of this appeared in the official report, which in fact expressly stated that no drain was detected.
• For trench TR-02, field notes documented cobbles and brick/ceramic debris, again omitted from the final report.
• For trenches TR-03 and TR-03-02, the reports stated that the fill contained 1–5% “blocs (Ø max. 100 mm),” even though the report’s own glossary defined “blocks” as having diameters over 300 mm. It was common ground that this “100 mm” figure was a typographical error and should have read 100 cm. The same mistake had already appeared in the second report and went undetected at the third.
• The TR-03 logs also contained an incorrect date and omitted mention of wood debris recorded in the field.

The judge characterised these as numerous and significant errors, especially regarding block sizes, which were critical for contractors and disposal sites in evaluating handling and tipping requirements. Since the final report was signed by two engineers, including an associate with more than ten years’ experience, the court held that an expectation of high professional care applied. The combined effect of misdescribed or omitted materials and the unit-error on block diameter led the court to conclude that GHD’s reporting fell below the required standard and constituted professional fault.

The St-Michel disposal site and lack of causation

Nevertheless, the court distinguished between fault and compensable damage regarding the soil disposal dispute. The College argued that GHD’s errors, especially the wrong “100 mm” block size, induced the St-Michel site to accept the material on paper and then reject it in practice, leading to costly redirection to the more distant Laval site and associated delays.

The court noted that there was no persuasive evidence—no written acceptance, and no testimony from St-Michel personnel or from Uni-Val representatives—proving that St-Michel had formally accepted the material based on the erroneous logs. More fundamentally, a careful reading of the report, even in its flawed form, showed that the soils contained scories, asphalt and brick fragments, and that certain layers had gravel contents exceeding the 25% maximum allowed by St-Michel. Those characteristics alone should have disqualified the excavated material from the site.

Put differently, even if the block-diameter error had been corrected, the material would still have been ineligible for St-Michel under its own guidelines. The decisive cause of the disposal problem was therefore Uni-Val’s misinterpretation of the report and its incorrect decision to use the St-Michel site at all, not GHD’s faulty drafting. On this part of the claim, the College established fault and damages but not the necessary causal link, so the damages claimed for having to change disposal sites were rejected.

Assessment of damages relating to surexcavation

The College’s remaining claim sought to recover additional costs and delay allegedly stemming from the unexpected depth of fill in the southern footprint, which traced back to the mislocated boreholes. It broke this into three items:

• A portion ($13,670 before tax) of subcontractors’ invoices associated with the surexcavation, with the College voluntarily claiming only 25% of those amounts, recognising that some degree of excavation would always have been required.
• $27,835 (before tax) representing Lavacon’s own invoices for extra work, inclusive of profit and administration mark-ups, bonding, insurance and quality-control costs.
• $97,027 (before tax) in prolongation costs, calculated as 26 days of site delay at a daily rate of $3,731.81 after settlement discounts.

The court accepted that the first and third categories of GHD faults (mislocated boreholes and failure to detect the deep fill) had caused some extra excavation and some delay. However, it found the College’s allocation of 26 full days of delay to the surexcavation exaggerated and poorly supported. The project schedule envisaged only ten days for all excavation to reach natural soil. It was therefore implausible that a 12% increase in the excavation volume—based on GHD and Lavacon’s own evidence about the relative size of the surexcavation zone—could cause 26 extra days on its own.

The evidence showed that most of the 26-day delay actually resulted from a different problem: a retaining wall that Lavacon built under the existing building had to be demolished and rebuilt because the contractor failed to have GHD verify that natural soil had been reached before placing the wall. That issue was attributable to Lavacon and its subcontractors, not to GHD.

Because the record did not permit a precise breakdown of days attributable solely to the extra depth of fill versus the retaining-wall error, the judge exercised his discretion to arbitrate damages. He fixed the delay attributable to GHD’s fault at two days, yielding prolongation damages of $7,563.62 (before tax).

He then addressed the other financial components:

• The 25% share of subcontractor invoices ($13,670) was allowed in full, on the basis that some of the described work clearly related to surexcavation and that the College was already taking a conservative approach by not claiming 100% of the amounts.
• Lavacon’s $27,835 in extra-work invoices was allowed only in part. Recognising that a significant portion related to demolishing and reconstructing the retaining wall—work attributable to Lavacon’s own mistake—the court cut this item by half, awarding $13,917.50.

Together, these amounts ($7,563.62 + $13,670 + $13,917.50) produced total capital damages of $35,151.12 before taxes.

Interest, costs and expert fees

On interest, the judge considered that it would be unfair to run interest from the College’s first demand letter in December 2020, because at that time the College had not yet paid anything to Lavacon. Instead, he started interest from 2 March 2021, the date when the delay in complying with the second demand (sent 22 February 2021, after the Lavacon settlement) expired. The award attracts the legal interest rate plus the statutory additional indemnity under article 1619 C.c.Q.

As to costs, the court held that, even though the College succeeded only in part, it remained the party who “won” the case. Furthermore, in the aspect where it failed on causation (the disposal-site issue), it had nevertheless established fault and damages. Accordingly, the court granted the College its full legal costs, including its geotechnical expert’s fees of $6,438.60, which were found to be reasonable and proportionate.

Overall outcome and successful party

In the final judgment, the Superior Court of Québec concluded that GHD Consultants ltée committed professional faults by failing to carry out a geotechnical campaign that respected established industry standards for borehole number and placement, and by producing reports riddled with errors and omissions. These faults deprived the College of a fully reliable understanding of excavation quantities and contributed to underestimation of the depth of fill in a key portion of the site. However, the College did not prove that GHD’s reporting errors caused the separate disposal-site problem; those damages were therefore not recoverable. Balancing the evidence, the court ordered GHD to pay Collège André-Grasset (1973) inc. capital damages of $35,151.12 (plus applicable taxes), together with legal interest and the statutory indemnity from 2 March 2021, and awarded the College its costs including $6,438.60 in expert fees, making the College the successful party with a total monetary award consisting of this capital sum, taxes, and all awarded interest and costs.