Construction Contract Ontario: What to Check Before You Sign
Ontario Construction Contracts: What to Check Before You Sign
Understand the scope, price, allowances, deposits, draws, holdbacks, changes, delays, warranties and exit clauses before your project starts.
This is the main Ontario hub for homeowners signing a custom-home, renovation, addition or major construction contract. Start with the problem worrying you most, then open the detailed guide.
Start free. Pay only when you need a deeper review.
The first problem is often easy to spot: a missing scope, vague allowance, front-loaded payment, weak completion clause or one-sided change provision. Start with the Free Scan, then choose the level of help the project justifies.
Contract Scan
Upload the contract, estimate, drawings and schedules. Find the most serious construction and commercial risk first.
Start Free ScanFull Contract Review
Receive a detailed review of scope, allowances, payments, changes, scheduling, closeout and questions to send the contractor.
Upload for ReviewOntario Lawyer Review
Use a lawyer for enforceability, cancellation, termination, liens, holdback, dispute strategy and project-specific legal advice.
See Lawyer ReviewWhat are you worried will happen after you sign?
Homeowners rarely search for contract doctrine. They search because the price may change, the deposit feels too large, the scope is vague, the completion date means nothing or the contractor has stopped returning calls.
Ontario facts to know before relying on any contract article
- Contracts signed in your home: Ontario says a home-renovation or repair contract worth $50 or more and signed in the home generally carries a 10-calendar-day cooling-off period. If the homeowner requested work during that period, reasonable compensation may still be payable for supplied work and non-returnable materials. Ontario renovation rights.
- Holdback: the Construction Act generally requires 10% holdback on the price of services or materials as they are actually supplied. Mandatory annual basic-holdback release rules took effect January 1, 2026, and transition rules can affect older contracts. Current Construction Act.
- Prompt payment: where the Act applies, an owner disputing a proper invoice generally must deliver the prescribed non-payment notice within 14 days. Do not substitute an ordinary complaint email for the required process. Construction Act forms and notices.
- New-home builder licensing: Ontario new-home builders and sellers must be licensed by the HCRA. The Ontario Builder Directory shows current licence and regulatory information. Ontario Builder Directory.
- Contract homes: Tarion says significant owner control or responsibility for essential construction elements can cause a custom home to be treated as owner-built rather than an eligible contract home. Tarion contract-home guidance.
- WSIB: clearance requirements depend on the work. A limited exemption exists when an occupant or family member directly retains a contractor for qualifying existing-home renovation work, but the exemption does not automatically extend through the contractor’s subcontract chain. WSIB clearance policy.
17 subjects the contract should address clearly
A good contract does not need to be needlessly complicated. It must be specific enough that the owner, builder, lender, consultant and future decision-maker can identify what was promised and how changes will be handled.
Ontario Construction Contract Centre
Every page below is published. Each guide covers one contract problem in depth and links back to this centre and the related topics needed to understand the complete issue.
1. Before you sign
Confirm the parties, contractor credentials, document completeness, legal review and the warning signs that should stop the signing meeting.
2. Scope, price, allowances and materials
Define what the price buys, who carries cost risk, how selections are reconciled and what happens when products or site conditions change.
3. Deposits, invoices, draws, holdbacks and liens
Keep payments connected to real value, preserve prompt-payment rights and administer Ontario’s current holdback and lien rules.
4. Changes, schedules and project control
Control who can make decisions, how they are priced, which records prove approval and how time is added to the schedule.
5. Cancellation, termination, abandonment and disputes
Use the correct legal route when work fails, the relationship breaks down or the parties need a neutral decision.
Real contract problems are usually ordinary sentences
The expensive problem is rarely a clause titled “How We Will Surprise You.” It is a short sentence that leaves out the detail everyone assumed was understood.
“Excavation included”
Does that include rock, groundwater, excess-soil disposal, imported granular, compaction and winter conditions?
Ask for inclusions, exclusions and unit rates.“Kitchen allowance: $25,000”
Does that cover cabinets only, or also delivery, installation, hardware, counters, HST and builder markup?
Ask what the allowance actually buys.“Completion: approximately summer”
What starts the clock, what counts as completion, which delays extend it and what notice must be given?
Ask for a schedule process, not a hopeful date.“Equal or better substitutions permitted”
Who decides what is equal, must the owner approve it, and is there a credit if the replacement costs less?
Ask for written approval and comparison criteria.“Changes billed as extras”
Who can authorize them, what markup applies, are deletion credits fair, and must the price be known first?
Ask for one written change-order procedure.“Final payment at substantial completion”
Does this occur before occupancy, deficiencies, manuals, warranties, seasonal work or lien-risk procedures are finished?
Ask for exact final-payment conditions.Ontario construction contracts in plain English
Does every Ontario construction contract have to be written?
Is 10% the legal maximum construction deposit?
Should every payment wait until work is complete?
What is the Ontario construction holdback?
Can a verbal promise still matter?
Can work proceed without a signed change order?
Does Tarion cover every custom home?
Is the Contract Checker legal advice?
Reviewed July 30, 2026. This page provides general educational information, not legal, accounting, insurance or engineering advice. Ontario law, Tarion coverage, HCRA licensing and WSIB obligations depend on the project and can change. Have an Ontario construction lawyer review the actual agreement before signing, cancelling or terminating it.
Do not guess what your contract means
Upload the contract, quotation, drawings and schedules. Start with the Free Scan. Choose the $99.99 builder-reviewed report when you need a complete commercial review, or an independent Ontario lawyer review from $499.99 when the decision is legal.
BuildersOntario.com is run by ICFHome.ca — ICF custom-home specialists since 1995. Straight answers on budget, permits, and ICF. No pressure.
Get a Ballpark Estimate →Book a 30-Min Call

Hello,
A quick question I was hoping you can assist me with; if a contract between a home builder and customer is signed but does not contain any dates (i.e. start date, completion dates etc.) is it still a valid contract?
Thank you.
Would like a legal and binding contract for small construction in and around a house.
Exactly what I was looking for. Thank you for posting this!