A renovation can change for good reasons: concealed damage, a revised layout, or a product that is no longer available. A written change order keeps everyone working from the same decision. It should explain the work, price, and schedule effect before that change proceeds.
This is practical information, not legal advice. Contract rights depend on the agreement and facts. Get advice from an Ontario construction lawyer when a change is large, disputed, tied to a lien or termination, or likely to affect safety or occupancy.
What does Ontario say about changed work?
Section 10 of Ontario's current Consumer Protection Act, 2002 generally prevents a supplier from exceeding an estimate incorporated into a consumer agreement by more than 10%. It also permits the parties to amend the estimate or price when the consumer requires additional or different goods or services. Ontario's renovation guidance says the new work and estimate should be discussed, approved, and signed as a change to the contract. The 10% rule is not permission to add an unexplained 9.9%.
Why does a change order happen?
| Trigger | Question to answer | Useful evidence |
|---|---|---|
| Owner request | What is added, removed, already ordered, or no longer needed? | Selection, sketch, product details, and credit for deleted work |
| Concealed condition | Could it reasonably have been known or included before opening? | Photos, location, original scope, investigation, and qualified opinion |
| Design or authority revision | Which accepted drawing, inspection note, or professional direction controls? | Dated revision and responsibility for related work |
| Product or schedule change | Is the substitute equivalent, and who carries the price or delay under the contract? | Supplier notice, approved substitute, delivery date, and schedule effect |
What belongs in a change order?
Identify the project, parties, original contract, change number, and date. Describe the reason, added work, deleted work, credits, materials, labour, subcontractors, equipment, delivery, disposal, permits, markup, tax, and net total. State the revised contract total and schedule effect, including no effect when that is true. Attach photographs, drawings, specifications, or inspection notes that define the decision, then record dated acceptance by authorized people before work begins.
Electronic approval can be valid. Ontario's Electronic Commerce Act, 2000 generally recognizes electronic documents, signatures, and contract formation, subject to its rules and exceptions. Follow the approval method in the contract. A numbered document with recorded acceptance is clearer than reconstructing an informal message exchange.
What should happen when a wall reveals a problem?
Pause the affected work, protect people and property, document the condition, and bring in the qualified person the issue requires. Check the original scope and exclusions before accepting that the repair is extra. If suspect material may be disturbed, stop: Health Canada's asbestos guidance recommends professional testing before renovation when asbestos may be present. Hazard assessment takes priority over the construction schedule.
How should price and time be shown?
The arithmetic should follow the contract's agreed method. Credit deleted work and allowances before adding replacements, avoid billing the original scope twice, and explain any markup. Time deserves the same treatment: state added or saved working days, affected milestones, delivery dependencies, and the date for confirming any unresolved effect. A zero-dollar substitution can still move completion.
What if you disagree with the change?
Put the disagreement in writing, identify the contract clause and amount, preserve photographs and records, and follow the notice and dispute procedure in the agreement. Pay undisputed amounts as required. Do not use the statutory holdback as a general complaint fund; Ontario's Construction Act gives holdback and lien rights their own rules. Get legal advice early for a material payment, lien, termination, safety, or occupancy dispute.
How do you prevent surprise changes?
Finish major design and selections before pricing, investigate expensive unknowns where practical, read allowances and exclusions using the Ontario quote guide, and keep a separate homeowner reserve using the contingency guide. Name who can approve changes and maintain one current contract total and schedule. Everyone should know what changed, what it costs, and who approved it.
