Contractor App Builder

Change Orders: How Small Contractors Document and Charge for Extra Work

When a change order is needed, what it must say, how to price it with overhead and profit, and how to get it signed before the work starts so you actually get paid.

Floot ·

Key Takeaways

  • Write it before you do it. A signed change order before the extra work starts is your strongest protection. Some states require it on home improvement contracts.
  • Every change order needs scope, price and time. Describe the work, state the cost added or credited, and say what it does to the schedule and payments.
  • Price changes with overhead and profit. Change work disrupts the job. Pricing it at bare cost means losing money on every change.
  • Your contract sets up every change order. Clear exclusions, allowances and a change order clause in the original contract make each later change a routine conversation instead of a fight.
  • Log them all, including credits and no-cost changes. A numbered change order log is how the final invoice, the schedule and your job cost all stay in agreement.

Quick-Start Prioritization Framework

SituationChange order?What to do
Customer asks for something not in the contractYesPrice it, get a signature, then do it
Hidden condition the contract excludes (rot, bad wiring)YesStop that part, photograph, price, get approval
Customer’s selection exceeds the allowanceYes, or an allowance reconciliationShow the difference in writing and get it signed
Customer deletes part of the workYes, a creditWrite the credit amount so the final invoice is clear
Your own mistake or missed itemNoFix it at your cost and update your estimating checklist
Inspector requires work the plans showedUsually noIt was in scope; check the contract before asking

Every contractor has a story about the extra work they never got paid for. The homeowner asked for “just one more outlet,” then a niche in the shower, then a different vanity, and by the end the job had grown 4,000 dollars and the final invoice turned into an argument. Change orders are not a sign of a badly run job. Plans change and walls hide things. What separates profitable contractors is that every change gets written, priced and signed before the work happens. This guide covers what counts as a change, what a change order must include, how to price one with a worked example, and the legal basics in a few jurisdictions. It is general information, not legal advice.

What counts as a change

A change is any difference from the scope, price or time in the signed contract. That includes additions, deletions, substitutions, changes in sequence or schedule, and conditions you could not reasonably have known about that your contract does not cover.

The question is always: what does the contract say? If your estimate said “replace subfloor as needed,” rotten subfloor is in scope. If it said “excludes repairs to subfloor or framing not visible at time of estimate,” it is a change. That is why the estimating stage matters so much; your exclusions and allowances decide which surprises are yours.

Owner-requested changes

These are the easy ones to identify and the easiest to lose money on, because they come up in casual conversation on site. “While you’re here, could you…” is the most expensive phrase in residential construction.

Concealed or differing conditions

Rot behind tile, knob-and-tube wiring, a joist cut for old plumbing, buried debris in a footing. These are changes only if your contract excludes them. When you find one, stop work on that part, photograph it, tell the customer the same day, and price the fix before you do it unless it is a safety emergency.

Constructive changes

Sometimes nobody calls it a change, but the owner’s direction effectively changes the work: “Use the more expensive fixture,” or “You need to finish by the 15th now.” On federal jobs, FAR clause 52.243-4 treats such directions as change orders only if the contractor gives written notice stating the date, circumstances and source of the order and that it regards the order as a change. Private contracts vary, but the habit is the same: put it in writing quickly.

What a change order must include

A change order is a short amendment to your contract. It does not need to be long, but it needs to be complete.

  • Project name, customer, contract date and a sequential change order number.
  • Description of the change in plain language, specific enough that a stranger would know what was added, removed or substituted.
  • Reason, briefly: customer request, concealed condition, allowance overage, design change.
  • Price: the amount added to or credited from the contract, and the new contract total.
  • Schedule impact: days added, or “no change to completion date.”
  • Effect on payments: when the change is billed, for example with the next draw or on completion.
  • Signatures and dates from both parties before the work begins.

What some states require

In California, Business and Professions Code section 7159 says a change order on a home improvement contract becomes part of the contract only if it is in writing and signed by the parties before the work it covers begins. The same section requires the change order to describe the scope of the extra work, the cost to be added or subtracted, and the effect the order will have on the schedule of progress payments. Other states have their own home improvement rules, and your contract may add more. Check your state’s licensing board guidance.

Notice deadlines in the contract

Commercial contracts often require written notice of a claimed change within a set number of days. FAR 52.243-4, for example, does not allow costs incurred more than 20 days before the contractor gives written notice (except for defective specifications), and requires the contractor to assert its right to an adjustment within 30 days of receiving a written change order or giving notice. Read your contract’s change clause before you start the job, not when you need it.

How to price a change order

Price change work the same way you price the original estimate: direct cost, then overhead, then profit. Change work is usually less efficient than planned work. Crews stop what they are doing, materials come in small quantities, and the schedule shifts. If anything, change orders deserve a slightly higher margin, not a lower one.

LineAmount (USD)
Labor (10 hrs × $42)420
Materials380
Direct cost800
Overhead (20%)160
Break-even960
Price at 10% net margin1,067

A worked example: rotted subfloor at a toilet flange

During demo on a 20,100 dollar bathroom contract, you find rot around the toilet flange and under the tub apron, about 24 square feet. Your contract excludes concealed framing and subfloor repair. Here is the change order math with illustrative numbers.

Labor: 10 hours to cut out, sister one joist, and install new subfloor, at a 42 dollar burdened rate, is 420 dollars. Materials: plywood, lumber, adhesive and fasteners, 380 dollars. Direct cost: 800 dollars. Overhead at your 20 percent rate adds 160, for a break-even cost of 960. To earn a 10 percent net margin, divide 960 by 0.90: the price is 1,067 dollars. Schedule impact: one extra day before tile.

The change order reads: “CO #1. Remove and replace approximately 24 sq ft of deteriorated subfloor at toilet and tub apron; sister one floor joist. Concealed condition excluded under contract section 4. Add 1,067 dollars. New contract total 21,167 dollars. Adds 1 working day. Billed with the tile-complete payment.” Attach two photos.

Fixed price, time and materials, or not-to-exceed

Fixed price works when you can see the full scope, as in the example. When you cannot, offer time and materials with a stated hourly rate and markup on materials, or time and materials with a not-to-exceed cap. Whatever you choose, write the method on the change order before work starts.

Credits

When the customer removes work, credit the direct cost you will not spend, and consider whether overhead already incurred (estimating, ordering, scheduling) should be kept. State your credit policy in the original contract so a deletion does not turn into a negotiation.

Getting change orders approved without slowing the job

The common objection is that writing change orders stops the work. It does not have to.

Set expectations at contract signing

Walk the customer through your change order process when they sign: any change gets a written price, nothing extra happens without their signature, and changes are billed with the next payment. Homeowners who hear this up front rarely push back later.

Price fast

For small changes, carry a simple price list or unit costs (per outlet, per linear foot of trim, per square foot of subfloor) so the foreman or office can price on the spot. For bigger ones, commit to a price within 24 to 48 hours and work elsewhere on the job meanwhile.

Use electronic signatures

A change order sent as a link the customer can sign on their phone gets approved the same day far more often than one printed and left on the counter. Most contractor software includes this, and general e-signature tools work fine. Keep the signed copy with the job record.

Tracking change orders through to the final invoice

Keep a change order log for every job: number, date, description, status (pending, approved, rejected, credit), amount and schedule days. Update the contract total each time one is approved.

  • Add each approved change order to your job budget, so job costing compares the change’s cost with its price.
  • On progress-billed jobs, list each approved change order as its own line on the schedule of values.
  • Show approved change orders on each invoice so the customer sees the running total and is not surprised at the end.
  • Note pending change orders in your cash forecast, but do not count them as revenue until signed.
  • When you exchange lien waivers, check what they cover. California’s statutory conditional waiver on progress payment, for example, includes an exceptions area for unpaid extras, so disputed change order amounts can be preserved.

Common change order mistakes

Nearly all of these come from treating changes as informal.

  • Doing the work on a verbal “yes” and writing it up afterwards.
  • Vague descriptions like “extra electrical work” that the customer can dispute later.
  • Pricing changes at bare cost with no overhead or profit.
  • Leaving out the schedule impact, then being blamed for finishing late.
  • Not stopping work on a concealed condition before pricing it.
  • Missing a contract notice deadline on a commercial job.
  • Forgetting credits, so the final invoice looks padded.
  • Bundling several changes into one large change order at the end, which reads like a surprise bill.

If you would rather not manage this on paper

If you’d rather not keep change orders in a folder of PDFs, most construction software includes change orders with e-signatures. If none fits how you work, an AI app builder such as Floot can build a small web app from your own description, with a change order form, customer sign-off and a log tied to each job.

Frequently Asked Questions

Does a change order have to be in writing?

It depends on your contract and state, but writing protects you everywhere. In California, change orders on home improvement contracts become part of the contract only if they are in writing and signed by both parties before the work begins.

How much markup should I put on a change order?

At least your normal overhead and profit, because change work is usually less efficient than planned work. Many contractors use their standard overhead percentage and the same or a slightly higher profit margin. Some contracts set a maximum markup on changes, so check yours.

What if the customer refuses to sign the change order?

Do not do the extra work. If the change involves a concealed condition you cannot work around, explain the options in writing, document the condition with photos, and follow your contract’s dispute process. For anything significant, speak with a construction attorney.

Can I bill a change order right away?

Your change order should say when it is billed. Common choices are with the next progress payment, on completion of the change, or a deposit for large changes. State rules on billing ahead of work may still apply.

Is a text message approval enough?

A text is better than nothing as evidence, but it often lacks the price, scope and schedule detail a proper change order includes, and some states require a signed written change order. Send a proper change order for e-signature and keep the text as backup.

Do credits need a change order too?

Yes. A deduction changes the contract price just as an addition does. Writing it down keeps the final invoice clean and shows the customer you are fair.

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