What happens if a contractor breaches a construction contract in Ontario?

If a contractor fails to complete work, does it deficiently, or abandons a project in Ontario, you may have several legal tools available. A claim for breach of contract is the primary avenue, seeking the cost to complete or correct the work, loss of use, and other reasonably foreseeable losses flowing from the breach.

Ontario's Construction Act also provides important protections through the construction lien regime, but this runs in the other direction — it protects contractors and subcontractors who are not paid, not homeowners who receive poor work.

If you are the property owner, a key practical step is getting independent inspection reports and written estimates from other contractors showing what correction will cost. This documentation is critical to quantifying your damages claim. You also have a duty to mitigate — in many situations you should arrange for someone to complete or repair the deficient work rather than let the problem worsen.

Depending on the amount in dispute, claims for construction deficiencies can proceed in Small Claims Court or the Superior Court. The limitation period is two years from discovery of the deficiencies. For significant defects — structural issues, major systems failures — consulting both a construction lawyer and a professional engineer is advisable.