Last Updated: August 22 2026
In Ontario, when does poor construction work become a legally “defect” that can support damages for defective workmanship?
Poor construction work becomes a legally “defect” when it fails the contract-required standard or the reasonable workmanship standard for the trade, even if the work meets only the minimum building code requirements. Courts treat the issue as a factual question based on the construction contract terms (including any specifications, warranties, or stated quality), the applicable building bylaws and codes, and evidence of what “reasonable workmanlike” performance required in the circumstances, rather than code compliance alone. For example, compliance with the Building Code Act is the statutory minimum, and meeting it does not automatically prove the contractor complied with the contract, while code violations can be evidence of deficiency in the contractual performance. If you need help documenting likely defects and building an evidence-led claim strategy for your Ontario renovation or construction dispute, Marketing.Legal™ can help with digital marketing that connects you to the right resources, call (800) 551-5751.
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Construction and renovation projects that involve the efforts of contractors as well as subcontractors and tradespeople can become contentious when defects or flaws in the work arise. When such defects occur, the expense incurred to correct a defect as well as the delays in completing the project to completion, can be significant and sometimes results in a contentious lawsuit.
Note: Please contact Marketing.Legal™ by phone at: (800) 551-5751 to discuss any specific questions that you may have.
The Law
When Does Poor Work Legally Become a Defect?
Workmanship that fails to meet the standard required of the work is defective. The required legal standard may be of posh temple type quality, of the usual standards of the trade, of the basic minimum requirements of local bylaws and the applicable building code, or other requirements somewhere in between.
Of course, a defect is also often highly subjective. Excessively proud property owners may be more discriminating upon the quality of workmanship than the contractor who believes that the quality of workmanship, while imperfect, meets or exceeds the specifications stated as contractual obligations or the common law standard expected in negligence law known as a good and workmanlike manner. The contractor may also perceive, sometimes wrongfully, that simply satisfying the standards of workmanship prescribed by statutes such as the Building Code Act, 1992, S.O. 1992, Chapter 23 is satisfactory. Of course, a defect is a defect only when a judge says so. In Scott v. Sarsfield Foods Ltd., 2000 CanLII 3533, a defect was explained by Justice Stewart whereas it was said:
[37] Principles relied upon by both parties are summarized, to a large degree, in I. Goldsmith and T.G. Heintzman, Goldsmith on Canadian Building Contracts, fourth edition (Toronto; Carswell, 1988 at pp. 5-11 to 5-14 under a Breach Contract; 2. By Contractor(b) Defective Work which reads in part as follows:
Work which does not meet the requirements of the specifications contained in the contract, or which, in the absence of such specifications, is not a reasonable workmanlike quality, is not proper compliance with the contract and constitutes a breach. Furthermore, compliance by the contractor with the specifications will not be sufficient performance if the specifications were prepared by him and are deficient, even if they were approved by the owner. Whether work, or material supplied, is defective or not is, in each case, a question of fact, depending on the construction of the particular specifications where there are any, and on expert evidence as to what is reasonable where there are none.
Where a contract, either expressly or by implication, contains a particular standard for the work to be done, an owner is not entitled to insist on work of a higher quality.
On the other hand, compliance by the contractor with a statutory or regulatory standard of conduct may not be sufficient, if it is not the standard called for by the contract, or reasonable in the circumstances.
An owner who has accepted the work does not thereby necessarily lose his right to claim damages for defective work, unless the defects have been expressly approved, or unless approval of them can be otherwise inferred from the owner’s conduct. Sometimes a contract contains a provision guaranteeing certain parts of the work for a particular period, and any defects occurring during such period of guaranteed maintenance must be remedied by the contractor.
Generally speaking, a contractor is liable only for defects resulting from his own work or from work or materials of his suppliers and subcontractors. ...
Apart from being contractually liable to the owner, a contractor who has been guilty of negligent constrction in a dangerous or unsafe structure may be liable in tort to the owner and to third parties. ... The standard of care for which the contractor is responsible may be determined by his contractrs with the owner or subcontractor or, in the absence of specific provisions applying to the circumstances, by expert evidence about the standard of conduct in his industry.
Interestingly, it is important to note that while violations of the Building Code Act will constitute a defect, the reverse is untrue; whereas, compliance with the Building Code Act may still be a violation of the express terms, or the implied terms, of the contractual requirements. Essentially, compliance with the Building Code Act is the statutory minimum requirement; however, a higher level of performance may be required. As stated in Enfield Hardware Ltd. v. DeGier, 2002 NSSC 164, the usual standards of a trade may be higher than the minimum requirements of the applicable Code. If the contract calls for standards higher than the applicable Code, or a contract is silent on specific standards and therefore the usual standards of the trade apply, compliance with the mere minimum Code requirement may be deemed a defect. Specifically, in Enfield Hardware it was said:
[9] I want to make one very significant point. The homeowner is entitled to rely on the expertise of the contractor to complete the work in accordance with the terms of the contract. National Building Code violations may be evidence of a deficiency in the contract, which may in fact result in a breach of contract, but the reverse is not true. Compliance with the building code is not evidence of compliance with the contract. The contract rules the relations between the parties.
