How do you write a construction change order?
A solid change order names the project and contract, describes the changed work precisely, gives the reason, breaks down the price, states the schedule impact, updates the contract sum, and gets signed by everyone the contract requires.
To write a construction change order, put seven things on one document: the project and contract reference, a numbered change order ID, a precise description of the added, deleted, or modified work, the reason for the change, a price breakdown, the effect on the schedule, and the revised contract sum and completion date. Then get it signed by the parties the contract names, before the work starts whenever you can. A change order that is vague on scope or silent on time is an argument waiting to happen.
The change order is a contract amendment. Write it like one. The person reading it a year from now (an owner's accountant, a surety, an arbitrator) was not standing in the hallway when the owner asked for the extra outlets.
What a construction change order must include
| Section | What to write | Why it matters |
|---|---|---|
| Header | Project name, contract number or date, owner, contractor, CO number, date | Ties it to the right contract and sequence |
| Description of change | What is added, deleted, or changed, with locations, quantities, and drawing or spec references | Prevents scope arguments later |
| Reason | Owner request, design error, RFI response, differing site condition, code requirement | Supports who pays and helps in disputes |
| Price | Labor, material, equipment, subs, markup, total; or T&M rates and a not-to-exceed | Shows how the number was built |
| Schedule impact | Days added or "no change," and any milestone dates affected | Time is the item most often left out |
| Contract summary | Original sum, prior changes, this change, new sum, new completion date | Keeps the contract total accurate |
| Signatures | Names, titles, dates for each party the contract requires | Makes it enforceable |
Step-by-step: writing a change order
1. Start from the trigger document
Most changes start somewhere on paper: an RFI response, an architect's supplemental instructions, a revised drawing, a field directive, or an owner email. Reference it by number and date. It proves the change came from the owner side.
2. Describe the work so a stranger could price it
Bad: "Additional electrical in break room." Good: "Add four 20A duplex receptacles on new dedicated circuit at break room counter, level 2, per RFI 14 response dated 3/12 and sketch SK-E4. Includes conduit, wire, boxes, devices, panel breaker, and patch and paint of affected wall." Include what is excluded, too.
3. State the reason
One sentence is enough: "Owner-requested addition," or "Revision due to conflict between M-201 and S-101 identified in RFI 9." The reason decides who pays and whether time is owed.
4. Break down the price
Show labor hours and rates, material, equipment, sub quotes, and markup as the contract allows. If the contract sets markup percentages for changes, use them and say so. See how to price a change order for the math.
5. Address time every single time
Either state the added days or write "no change to contract time." Leaving it blank can be read as giving up time you were owed.
6. Update the contract summary
Show the original contract sum, net of previous change orders, this change, and the new contract sum, plus the original and revised completion dates. This lets the owner, the GC, and your accounting all agree on the same number.
7. Route for signatures
Follow the contract: some require owner, architect, and contractor signatures; some allow the owner's rep alone up to a dollar limit. Send it promptly and track it.
8. Watch the notice deadlines
Contracts often set a time limit for asserting a change. Federal fixed-price construction shows how strict this can be: under the FAR changes clause, the contractor must assert its right to an adjustment within 30 days after receiving a written change order, although that period can vary under agency procedures. Your private contract may have a shorter or longer window, so check it.
Worked example: a tenant improvement change order
Say a GC is building out a $480,000 tenant improvement. The tenant asks for a glass sidelite next to the conference room door. The architect issues a sketch.
| Item | Detail | Amount |
|---|---|---|
| Framing sub | Reframe opening, new header | $1,150 |
| Glazing sub | Sidelite, frame, tempered glass | $3,480 |
| Drywall and paint | Patch and finish | $620 |
| GC labor | Supervision and protection, 6 hours at $85 | $510 |
| Subtotal | $5,760 | |
| Markup | 10 percent per contract | $576 |
| Total change | $6,336 |
The change order lists the sketch number, notes the glass lead time adds 5 working days to the conference room finish but does not move substantial completion, and shows the contract sum moving from $496,200 (after change orders 1 to 3) to $502,536. The tenant's rep and the GC sign it before the framing sub cuts the wall. The framing, glazing, and drywall subs each get their own subcontract change orders the same day, referencing CO 4, so the GC's costs and the tenant's price stay tied together.
Change orders on subcontracts
Subcontract change orders follow the same structure, with two additions. Reference the upstream document (the owner change order, directive, or RFI) so the GC can tie your change to its own. And make sure the time you ask for matches what the GC is asking from the owner, or you can end up absorbing a delay the GC was compensated for. If the GC asks you to proceed before its owner signs, ask for a written directive from the GC. The GC's direction is enough to support your claim against the GC, even if the owner never approves the GC's change.
Deductive change orders
When scope is removed, write a deductive change order the same way: describe what is deleted, show the credit calculation, and subtract any costs already incurred, such as material already bought or restocking fees. Owners sometimes assume the credit equals the original line value. It often does not.
Mistakes to avoid
- Vague scope that two people can read two ways.
- Leaving schedule impact blank.
- Lump-sum pricing with no breakdown, which invites a long review.
- Missing the contract's notice or submission deadline.
- Starting work on a verbal OK. Read how to handle verbal change requests from owners.
- Numbering change orders inconsistently across the job.
- Not updating the schedule of values once it is signed.
Templates and tools
Start from the construction change order template and log every change on the change order log template. For what comes next, see how to get change orders signed before doing the work and how to invoice change orders without delays.
Smart Business Automator builds change orders inside the project, routes them for approval, and carries the approved amount to the job budget and invoices. See change order approval automation.
Frequently asked questions
Who signs a construction change order?
Whoever the contract names, usually the owner (or owner's rep) and the contractor, and often the architect. For subcontract changes, the GC and the sub.
Is an email approval as good as a signed change order?
Sometimes an email can count as written approval, but many contracts require a specific signed form. Even when email is enough, follow up with a formal change order so the contract sum stays clean.
Can a change order reduce the contract price?
Yes. A deductive change order removes scope and lowers the contract sum. It should still show the breakdown and any credit calculation.
What is the difference between a change order and a change order request?
A change order request is your proposal for a change, with price and time. It becomes a change order once all required parties sign it.
