Key Takeaways
- 01A change order is a written, signed amendment to a construction contract that documents a change in scope, price, or schedule
- 02Extra work done on a verbal OK is the number one way contractors end up eating costs — get the signature before the work starts
- 03Every change order should state what's changing, why, the itemized cost, the new contract total, and the schedule impact
- 04Price change orders like mini-estimates: labor, materials, equipment, and subs, plus your normal overhead and profit markup
- 05Track the running total of approved change orders so you, the owner, and your invoices always agree on the current contract price
A change order is a written amendment to a signed construction contract that documents a change to the original scope of work — what the change is, what it costs, and how it affects the schedule. Once both parties sign it, the change order becomes part of the contract, and the contract total and completion date adjust with it.
That's the whole idea. The discipline is in actually using one every time the job changes, before the changed work begins. This guide covers what belongs in a change order, how to price one, and how to keep "can you just also…" requests from quietly eating your profit.
What Is a Change Order in Construction?
Construction projects rarely finish exactly as drawn. The owner upgrades a fixture, the framing opens up a surprise, the inspector wants something done differently. A change order is how those changes get handled without tearing up the construction contract and starting over: it amends the existing agreement in writing.
A change order typically does three things at once:
- Describes the change — the added, removed, or altered work, specifically enough that both parties would describe it the same way
- Prices the change — an itemized cost (or credit, if work is removed) and the new total contract price
- Adjusts the schedule — how many days the completion date moves, if any
Because it's signed by both parties, a signed change order is generally binding just like the contract it amends. Some states require written change orders on residential home-improvement work, and many contracts make unwritten changes unenforceable — the exact rules vary by state and by contract, so check what yours says and verify with your state board if you're unsure.
On larger commercial jobs you may also see a construction change directive (CCD): the owner or architect directs the work to proceed before the price is agreed, and the cost gets settled after. On residential and small commercial work, though, nearly all changes should run through a normal, priced-and-signed change order.
Why You Should Never Do Extra Work Without One
The most expensive sentence in construction is "sure, we can do that" — spoken on-site, priced never.
Without a signed change order:
- You may not get paid for the extra work. If it's not in the contract and not in a signed change order, the owner can dispute it, and you have little to stand on beyond memory of a conversation.
- Scope creep compounds. One free "small extra" sets the expectation that the next one is free too. Ten of them is a week of unpaid work.
- The schedule slips with no cover. If extra work delays completion and nothing documents why, the delay looks like your fault — which matters if the contract has late penalties.
- Your final invoice becomes a fight. When the contract says one number and you bill another, even an owner who agreed to every change along the way will question the difference.
A clean change order habit fixes all four. It also protects the owner — they see the cost of each request before committing to it, which builds trust rather than straining it.
What Causes Change Orders?
Most change orders trace back to one of five causes:
- Owner requests. Upgraded materials, an added circuit, a moved wall, "while you're here" work. The most common cause and the easiest to price.
- Unforeseen conditions. Rot behind the siding, rock where the footing goes, wiring that isn't to code once the wall opens. You can't price what you can't see when bidding the job.
- Plan errors or omissions. The drawings conflict, or something needed to finish the job was never drawn at all.
- Code and inspection requirements. The inspector requires work beyond what the contract documents showed.
- Material availability and substitutions. A specified product is discontinued or backordered, and the substitute costs more (or less — credits are change orders too).
Naming the cause in the change order matters: it tells the owner why this wasn't in the original price, which is most of the argument you'd otherwise have later.
What Should a Change Order Include?
The running-total lines are the part most homemade forms skip and the part that prevents the end-of-job argument: every change order shows the math from the original price to the current one, so there's never a surprise number.
How to Write a Change Order (Step by Step)
Stop and document the change
When a change comes up, don't just absorb it into the workday. Write down what's changing and why, and photograph anything relevant — especially hidden conditions like rot or bad wiring, where the photo is your evidence that the extra work was real.
Price it like a mini-estimate
Estimate the labor hours, materials, equipment, and any subcontractor costs for the change, then apply your normal overhead and profit markup — the same way you built the original estimate. Include costs the change creates indirectly: demolition of finished work, re-mobilizing a sub, an extra inspection trip.
Put it in writing on a change order form
Fill in everything on the checklist above, including the new contract total and the schedule impact. Keep the description plain and specific — "supply and install 14 additional linear feet of base cabinet, per attached sketch" beats "kitchen changes."
Get both signatures before the work starts
This is the step that makes the rest worth doing. Present the change order, walk the owner through the cost and the schedule impact, and collect signatures — an e-signature collected on your phone works and keeps a timestamped record. No signature, no changed work.
Update the contract total and invoice it
File the signed change order with the contract, update your running contract total, and bill the change according to its payment terms — usually with the next progress payment, so the paperwork and the money stay in sync.
Say you're three weeks into a bathroom remodel and the owner asks you to move a doorway 2 feet and add a pocket door.
- Labor: 14 hours × $65/hr = $910
- Materials: pocket door kit, framing lumber, drywall, mud, trim = $540
- Electrician (relocate switch): $300
- Subtotal: $1,750
- Overhead & profit markup at 20%: $350
- Change order total: $2,100, plus 2 days added to the completion date
The change order shows: original contract $18,400 + previous change orders $650 + this change $2,100 = new contract total $21,150. The owner signs before you open the wall.
How to Price Change Order Markup
Price change order work with at least your normal markup — the one that covers your overhead and profit on the base contract. Many contractors charge a somewhat higher markup on change orders than on base-contract work, because changes carry extra costs that are easy to miss: re-planning, disrupted sequencing, small-quantity material runs, and the administrative time to document and process the change itself.
Whatever rate you use, two rules keep it defensible:
- State the markup approach in the original contract. A line like "changes to the work will be billed at cost plus 20%" turns markup from a negotiation into a lookup.
- Do the math honestly and show it. An itemized change order with visible markup gets signed; a single mystery number gets questioned. Run the numbers with a markup calculator if you want to sanity-check the margin the rate actually leaves you.
Estimate and Document Changes in Minutes
InvoiceOwl lets you build an itemized estimate for the extra work on your phone, collect the client's e-signature on the spot, and convert it to an invoice when the work is done.
Start Your FREE TrialCommon Change Order Mistakes to Avoid
- Working on a verbal OK. "Go ahead, we'll sort out the paperwork later" is how contractors donate labor. The signature comes first — a quick e-signature on-site removes the excuse that paperwork slows the job down.
- Pricing only the direct costs. The two hours of demolition, the second inspection trip, and the day of re-sequencing are real costs. If the change order doesn't capture them, your margin does.
- Ignoring the schedule. A change order that adds work but not days sets you up to be "late" on a job where the owner added a week of scope.
- Losing the running total. If you can't state the current contract price from your paperwork alone, neither can the owner — and the final invoice becomes a reconstruction project.
- Skipping credits. When scope is removed or a cheaper substitute is used, issue a deductive change order. Owners who see you document changes in both directions sign the additive ones faster.
How Change Orders Affect Invoicing and Payment
A signed change order changes the contract price, so it has to flow into how you bill. On jobs billed in stages, add approved change orders to the next progress invoice as their own line items, referencing the change order number — that way each invoice ties back to signed paperwork, and the sum of your invoices matches the current contract total. Keep the payment terms for change order work consistent with the contract unless the change order itself says otherwise.
If you estimate and invoice from the same system, this bookkeeping mostly does itself: build the change as its own itemized estimate with the estimate generator, get it e-signed, and convert it to an invoice when the work is done.
Frequently Asked Questions
Generally yes — a change order signed by both parties amends the contract and is binding like the contract itself. Requirements vary by state and by contract: some states require home-improvement changes to be in writing, and many contracts state that unwritten changes are unenforceable. When in doubt, get it in writing and signed; it's never wrong.
Sometimes courts allow recovery for verbally approved extra work, but it's an uphill, evidence-poor fight you don't want. Practically: assume that work without a signed change order is work you may not get paid for. If work truly can't wait, at minimum get written approval by text or email with a price before proceeding, and follow up with the formal change order.
Either party can propose one — the owner requesting a change, or the contractor flagging a hidden condition or required substitution. On jobs with an architect or general contractor, the contract usually names who is authorized to approve changes. It becomes effective when the parties the contract requires have signed it.
At minimum, your normal overhead-and-profit markup — the work still consumes overhead and deserves profit. Many contractors apply a somewhat higher rate on changes to cover disruption and administrative time. The most important thing is to state your change order markup approach in the original contract so it's agreed before the first change appears.
A change order is agreed and priced before the changed work proceeds. A construction change directive (used on larger commercial contracts) orders the work to proceed before price and time are agreed, with the adjustment settled afterward. Small residential jobs should stick to signed change orders.
No. A deductive change order documents removed scope or a cheaper substitution and credits the owner, lowering the contract total. Documenting decreases with the same rigor as increases keeps the running contract total honest and builds trust.
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