Homeowner vs. Contractor Disputes in Ontario

Renovation and home construction projects involve a lot of moving parts — budgets, schedules, trades, materials, and personal taste — and disputes tend to cluster around a handful of recurring problems. Incomplete or abandoned work is one of the most common: a contractor stops showing up, either because of a dispute over payment, a scheduling conflict with other jobs, or financial trouble of their own.

Cost overruns are another frequent source of friction, particularly where a project accumulates extra charges over time without a clear paper trail — see our companion guide on change orders in Ontario construction contracts for how scope changes are supposed to be documented. Delays beyond the agreed schedule, whether caused by the contractor, supply issues, or circumstances outside anyone’s control, are also common, especially on larger renovation projects with many interdependent trades.

Finally, quality and deficiency disputes — work that does not meet the agreed standard, or does not comply with the Ontario Building Code or manufacturer specifications — come up often enough that they are covered in more depth in our guide to construction deficiency claims in Ontario.

These flashpoints rarely show up in isolation. A delay often leads to a cost overrun as trades are rescheduled and materials prices shift, and a quality dispute can surface only once the homeowner starts questioning why the budget crept up in the first place. Recognizing that these issues tend to compound is part of why documenting the project from the start — not just reacting once a problem becomes obvious — tends to put homeowners in a stronger position if a dispute eventually needs to be resolved formally.

Once a problem surfaces, the most useful first step is usually to gather documentation: the written contract (or the best available record of what was verbally agreed), any change orders or email exchanges about scope and pricing, invoices and payment records, and photographs of the work at relevant stages. This record generally shapes everything that follows, including how strong any later claim is likely to be.

It is also worth reviewing the contract itself for anything specific to the dispute — payment schedule terms, a defined process for addressing deficiencies, warranty provisions, or a dispute resolution clause requiring mediation or arbitration before court. Many homeowners skip this step in the heat of the moment, but the contract’s actual wording often determines what options are realistically available.

It is also worth keeping a simple running log of conversations with the contractor, including dates and a short summary of what was discussed or agreed, especially where instructions are given verbally on site. This kind of informal log is not a substitute for a written contract or signed change order, but it can help fill in gaps if a dispute later turns on what was actually said and when.

Ontario’s Construction Act, 2019 requires the person paying for construction services — often the homeowner, where the contract is directly with the homeowner — to retain a holdback, generally 10% of the contract price, for a set period after substantial performance or completion. This holdback exists primarily to fund potential lien claims from unpaid subcontractors and suppliers, but it also gives the homeowner a pool of funds that has not yet been released when a dispute with the general contractor comes up. See our dedicated guide to holdback requirements in Ontario for the mechanics.

On the other side, if the homeowner withholds payment the contractor believes it is owed, the contractor may respond by registering a construction lien against the property — generally within 60 days of the relevant triggering event, and perfected through a court action within a further 90 days. A registered lien can complicate a homeowner’s ability to sell or refinance the property, which is often what pushes a payment dispute toward faster resolution. See our guides to construction liens in Ontario and discharging or vacating a lien for more detail on both sides of that process.

Before moving toward a formal claim, many disputes benefit from a written demand that clearly describes the problem, references the relevant contract terms, states what outcome is being sought — a refund, completion of outstanding work, a repair of a deficiency — and sets a reasonable deadline for a response. A demand letter puts the issue on the record and often resolves matters without anything further becoming necessary, since many contractors would rather fix a documented problem than risk a claim.

Keeping the letter factual and specific — dates, amounts, the exact provisions of the contract at issue — tends to carry more weight than a letter that is vague or emotional. A copy of this correspondence also becomes useful evidence later if the dispute does end up escalating further.

It is generally sensible to send a demand letter by a method that confirms delivery, such as email with a read receipt or courier, rather than relying only on a text message or a verbal conversation. This creates a clear record of exactly when the contractor was given notice of the problem and the deadline it was given to respond, which can matter later if the dispute proceeds further.

If a written demand does not resolve the dispute, the available next steps generally depend on the amount at stake and the nature of the problem. For claims up to $35,000, Ontario’s Small Claims Court is designed to be a more accessible, lower-cost venue, with a simplified process that does not require a lawyer. For larger amounts, or disputes involving more complex issues such as a registered construction lien, the Superior Court of Justice is generally the appropriate forum.

Some contracts also require mediation or arbitration before a court claim can be started, so it is worth checking the dispute resolution section of the contract before assuming litigation is the next step. On an eligible contract, adjudication under the Construction Act can also offer a faster route to resolving a specific payment dispute — see our overview of construction adjudication in Ontario for how that process works.

The amount at stake is usually the deciding factor in choosing between these paths. A homeowner disputing a few thousand dollars over an incomplete repair is generally better served by the simplicity of Small Claims Court than by a lengthier Superior Court action, even if the Superior Court technically has jurisdiction over the amount. Conversely, a dispute involving tens of thousands of dollars, a registered lien, or multiple parties — a contractor, several subcontractors, and perhaps an architect or engineer — often outgrows what Small Claims Court is designed to handle, making the Superior Court the more practical venue despite its added cost and complexity.

Many homeowner-contractor disputes trace back to gaps in the original contract — vague scope descriptions, no clear payment schedule, and no defined process for handling changes. A clear, detailed written contract at the outset, along with disciplined use of change orders for any scope adjustments, generally reduces the risk of a dispute later. See our guide to renovation contracts in Ontario for what a solid residential contract generally covers.

This article provides general information about how homeowner-contractor disputes generally unfold in Ontario and is not legal advice about any specific project or dispute. See our tools and contact page for further resources.