What is a change order in construction?

A change order is a documented addition or alteration to the original contracted scope, with its own price. It is the formal mechanism for charging work that was not in the original quote, whether because the homeowner requested something new or because the original scope had a gap.

Are change orders always the contractor's fault?

No. Some are genuinely unforeseeable, such as hidden water damage or outdated wiring discovered when walls open. Some are homeowner-requested upgrades. The preventable ones come from vague scope language and missing exclusions in the original quote, which careful reading can catch before signing.

How can I reduce change orders on my renovation?

Resolve every vague phrase in the quote before signing, confirm allowance amounts match your expected finish level, get exclusions in writing, and ask the contractor what they consider the most likely surprise on your specific project. Disputes shrink when the paper is specific.

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Why change orders happen — and how your quote predicted them

From the desk of QuoteGuard's founder — 19 years quoting residential construction in Ontario · June 2026

A change order is the price of a sentence that wasn't in the original quote. That is the whole anatomy of it. Sometimes the missing sentence was unknowable — nobody can see inside a wall. But after 19 years of writing quotes and pricing the change orders that followed, I can tell you most of them were visible on the page before anyone signed. You just have to know what they look like before they hatch.

The three species of change order

1. The genuine surprise. The wall comes down and there's knob-and-tube wiring, rot around a window, asbestos in the floor tile. Unforeseeable, unavoidable, and fair to charge for. In older Canadian housing stock — anything pre-1970s especially — some category of surprise is close to certain, which is why a renovation contingency of 10–15% on top of any quote is planning, not pessimism.

2. The homeowner upgrade. Mid-project you decide the heated floor is worth it after all. Also fair — you changed the scope. The only thing to insist on is that it is priced and signed before the work happens, never settled “at the end.”

3. The predictable one. This is the species that breeds resentment, and it hatches from quote language like this:

The quote says: “Electrical as required.”

Required by whom? Code-minimum to pass inspection is one number. The pot lights, the dedicated appliance circuits, the panel upgrade your project actually triggers — that is another. This phrase converts to a change order more reliably than almost any other.

The quote says: “Patch and repair walls as needed.”

Does “repair” include skim-coating the whole wall when the old plaster crumbles? Repainting the ceiling the patch bleeds into? “As needed” means you and the contractor each have a private definition — and they get reconciled later, with money.

The third species is the preventable one, and the prevention happens before signing, not during the build. Every vague phrase you convert into a specific written sentence is a future change order you just deleted.

Reading a quote for change-order exposure

Hunt the weasel phrases: “as required,” “as needed,” “as discussed,” “TBD,” “by others.” Each one is an unpriced decision. Ask what each phrase specifically includes, and get the answer added to the quote.
Read the exclusions list — and respect it. A quote that states what is not included was written by someone who has been through this. No exclusions section at all usually means the exclusions exist anyway; they are just undocumented, and they will surface as species three.
Check the allowances against your expectations — allowance overages are change orders by another name, and they are the most predictable of all.
Ask the contractor directly: “On a project like mine, what is the most likely surprise?” An experienced contractor answers immediately and specifically. That answer tells you where to budget contingency — and the willingness to answer tells you how change orders will be handled when they come.

What fair change-order handling looks like

Even a tight quote will produce some change orders on a real renovation. The quote itself should say how: changes documented in writing, priced before the work proceeds, signed by both parties. If the quote is silent on the mechanism, ask for a change-order clause before signing. It protects both sides — the contractor gets paid for legitimate extra work without an argument, and you never get a surprise line on the final invoice for something you don't remember agreeing to.

The pattern across all of this is the one from the main guide: budgets are not killed by the number on the quote. They are killed by the sentences that aren't there.

Want a second set of eyes on your quote?

QuoteGuard reviews your contractor quote against the scope of your project — built on 19 years of writing these documents. You get a report flagging missing scope, vague language, allowance risks, and the exact questions to ask. No subscription, one flat fee per report.

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