Paste the text thread, site notes and photos into ChatGPT or Claude together with your contract's change clause and your own rate sheet, then ask for a change order in a fixed layout: description, reason, priced lines from your rates, schedule effect and an approval line. Check every number yourself before anything goes to the client for signature.
A text thread proves the client asked. It doesn't give the price, the schedule effect or the signature your contract probably requires. Your contract's change clause governs how changes must be requested, priced and approved, so the AI works inside that clause: it drafts, you review, and prices come from your rate sheet, never from the model's memory.
What a message thread leaves out
Site messages are written for speed, between people who share a room and a plan. A change order is written for a stranger, possibly a lawyer, reading it a year later. The gap between the two is what the AI has to close, and it can only close what it is given:
| What the message says | What the change order needs |
|---|---|
| "Can we move the sink to the island?" | Exact scope: what moves, what stays, who does the work |
| "Sure, whatever it costs" | A price built from your rate sheet, with the markup your contract allows |
| "Hope that doesn't hold us up" | The schedule effect in working days, and any knock-on for inspections or deliveries |
| A thumbs-up reaction | An approval from someone the contract authorises, in the form it requires |
| "Also the lights, while you're there" | A separate priced line for each item, so any one can be removed |
The cost of leaving that gap open is easy to underestimate. Take a contractor who absorbs five small changes a job at three hours each, with labour costing $62 an hour. That is $930 a job before any margin, and across 12 jobs a year it is $11,160 of work nobody was asked to pay for. These are example figures. Count the changes on your last three jobs and cost them at your own hourly rate before deciding whether a routine is worth setting up.
Read the contract's change clause before drafting anything
Contract terms govern, so the first job is to extract the rules the draft must follow and keep them in one place. For a typical home-improvement contract (the wording below is illustrative), the sheet looks like this:
| Rule | What the example contract says | Why the AI needs it |
|---|---|---|
| Who may request or approve | The client or a named representative, in writing | Stops drafts going to the wrong signer |
| Required form | A written change order, signed before work starts, except in emergencies | Sets the "do not start" line |
| Pricing basis | Cost plus 15% overhead and profit on additions; credits at cost with no markup | The most common arithmetic slip |
| Rate source | Rates in the rate sheet are cost rates; markup goes on top | Prevents marking up twice |
| Response period | The client has two business days to approve | Sets the chase date |
| Schedule effect | Extension in working days, stated on the change order | Fills the schedule line |
| Emergencies | Work to protect people or property may start first, with a record sent the next day | Needed for the emergency case below |
Ask the model to build that table from your own clause rather than typing it by hand:
Read the change clause below and return a table with these rows: who may request or approve a change; required form; pricing method and markup; how credits are priced; response period; schedule extension rule; emergency exception; anything unclear or missing.
For each row quote the exact words from the clause, then give a one-line plain reading. Do not interpret beyond the text. If the clause is silent on a row, write SILENT.
[Paste the change clause here]Compare each quoted line with the contract yourself. The table is a working note, and the contract is what governs. A row marked SILENT, or wording that reads two ways, is a question for a lawyer, not a gap for the model to fill with a plausible guess. Keep the finished table in your project so every change order starts from the same rules.
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Buy nowGathering messages, photos and the rate sheet
Collect only what concerns the change: the relevant messages, the site note, the photos and the rate lines. Replace names, addresses and phone numbers with placeholders such as [client] and [address] before pasting. Copying text is cleaner than screenshots, but screenshots are fine when the thread holds images. Claude accepts up to 20 files in a chat, including JPEG, PNG, GIF and WebP images, and ChatGPT takes PNG, JPEG or non-animated GIF images of up to 20 MB apiece (both checked in November 2026; limits change, so look again before relying on them). A foreman's voice note can become a site note through your phone's dictation or a transcription app; the voice notes to job sheets tutorial covers that step.
Give each photo a one-line caption saying where, what and when ("Photo 1: former dishwasher space, soft subfloor, Tuesday"). Without captions the model guesses what it is looking at, and a guess inside a change order is a risk you don't need.
The rate sheet is a plain table of code, item, unit and cost rate, kept in a spreadsheet. Claude reads CSV uploads (and XLSX once code execution and file creation is switched on in its settings), and you can paste the rows into ChatGPT. Give the model the whole sheet, not an excerpt, because a missing line is where it starts inventing a number. An illustrative extract:
| Code | Item | Unit | Cost rate |
|---|---|---|---|
| CARP-01 | Carpenter labour | hour | $58.00 |
| LAB-01 | Labourer | hour | $38.00 |
| MAT-PLY34 | 3/4 in plywood, 4 x 8 sheet | sheet | $62.00 |
| MAT-FIX | Fixings and adhesive, per job lot | lot | $18.00 |
| DISP-01 | Disposal, small load | load | $25.00 |
The instruction that matters most goes with it: use only these codes, and if an item isn't on the sheet, write TBC and ask for a quote. To build the sheet from supplier quotes and keep it current, see building a supplier rate sheet for estimating.
A kitchen remodel, four messages and one soft subfloor
The contractor in this example is partway through a $48,500 kitchen remodel under the contract rules in the table above, with two small changes already approved (CO-01 and CO-02, $308.50 between them). Four messages arrive over three days:
- Monday, 4.12 p.m., client: "Can we add under-cabinet lighting along the sink wall? Warm white."
- Tuesday, foreman's site note: "Lifted the old dishwasher space. Subfloor soft, about 3 x 4 ft. Joists look sound. Photos 1 and 2."
- Tuesday, 6.30 p.m., client: "Fix the floor, obviously. And skip the crown moulding on the upper cabinets, we've decided against it."
- Wednesday, 9.05 a.m., electrician (subcontractor): "Under-cabinet strip, three runs plus a switch, $380 all in."
One standing instruction does the drafting. It lives in the project, and the messages, photo captions and rate sheet go in each time:
You draft change orders for a general contractor. Use the change rules table and the rate sheet in this project, and the messages and photo captions I paste.
1. One numbered line per change. For each give: description, reason (client request, unforeseen condition, required change or substitution) and the pricing lines.
2. Price only from rate-sheet codes or a subcontractor quote I have pasted. If a price is missing, write TBC and list the question to ask. Never use a price from memory.
3. Apply the markup and credit rules from the change rules table. Show subtotal, markup, additions total, credits, net change, the contract sum before this change (original sum plus approved change orders) and the revised contract sum.
4. State the schedule effect in working days and say what you assumed.
5. If a message is vague or two messages conflict, do not price it. List the questions instead.
6. End with an approval block that follows the contract: who signs, the response period and the do-not-start line.
7. List every assumption at the bottom.The first draft needed three corrections before it was fit to send as CO-03. This table is the corrected version (illustrative figures throughout):
| Line | Detail | Amount |
|---|---|---|
| 1. Replace damaged subfloor, about 12 sq ft, former dishwasher space | Carpenter 5.0 h x $58 = $290.00; plywood 1 sheet = $62.00; fixings $18.00; disposal $25.00 | $395.00 |
| 2. Under-cabinet lighting, three runs plus switch | Electrician's quote, materials included | $380.00 |
| Additions subtotal | $395.00 + $380.00 | $775.00 |
| Markup, 15% | $775.00 x 0.15 | $116.25 |
| Additions total | $891.25 | |
| 3. Credit: omit crown moulding on upper cabinets | Materials $210.00; labour 3.0 h x $58 = $174.00; no markup on credits | -$384.00 |
| Net change | $891.25 - $384.00 | $507.25 |
| Contract sum before this change | $48,500.00 original + $308.50 approved in CO-01 and CO-02 | $48,808.50 |
| Revised contract sum | $48,808.50 + $507.25 | $49,315.75 |
Schedule effect: one working day, with the subfloor done first and the electrician's visit after it. The three corrections were these:
- It marked up the credit. The draft applied 15% to the $384 credit, which gave $441.60 and a net change of $449.65, short of the correct $507.25 by $57.60. The change rules say credits are at cost, so the fix was to point the model at that row and ask it to redo the totals.
- It priced the plywood from memory. The pasted rate sheet had lost its plywood row, so the model used $48 instead of $62. With the full sheet pasted it used the sheet's figure. A missing row doesn't produce an error message. It produces a number.
- It overstated the scope. The draft said "full replacement of kitchen subfloor", but the site note describes a 3 x 4 ft patch. The line was rewritten to the measured 12 sq ft, with a sentence that if the damaged area is larger once exposed, a further change order follows.
The draft's assumptions list, at the bottom, is worth reading closely: it said the subfloor repair was limited to 12 sq ft, that the electrician's price included materials and the switch, and that no work in the sink area would start before signature. Each is a statement for you to confirm or correct. In this illustration the contractor needed about ten minutes for the change order, including those corrections, against 30 to 40 minutes writing it by hand. Time your own first three; if the saving is smaller, the routine still earns its place through the consistency of the paperwork. For the pricing logic in more depth, read how small building firms price variations.
Seven more messages, seven different drafts
Not every message should become a priced line. Some should become questions, some a notice, and one should become a record of work already done. Here is how the standing instruction should treat each:
| Message or note | The trap | What the draft should do |
|---|---|---|
| Client: "Can you make the shower niche bigger?" | No size, position or finish given | Price nothing; list the questions to ask the client |
| Foreman's photo of old wiring behind a wall that was meant to stay closed | Unforeseen condition; the price can't be known until it is exposed | Draft a notice that work stops in that area, and propose a provisional allowance or measure-on-exposure pricing if the contract allows, flagged for your decision |
| Inspector's note requires an extra smoke alarm circuit | Required change; who pays depends on the contract | Label the reason "required by inspection", attach the note, price from the rate sheet and quote the clause that decides who pays |
| Client picks tile A on Monday and tile B on Wednesday | Conflicting instructions | Show both in a dated decision log, price nothing, ask the client to confirm the final choice in one sentence |
| Supplier: chosen vanity delayed six weeks; client picks a substitute | Price and schedule effects in both directions | Draft a substitution: credit for the deleted item, addition for the new one, schedule effect and the client's written choice |
| Plumber's call at 6 p.m.: burst pipe, repaired that night | Emergency work started before approval | Draft an emergency work record (what happened, what was done, who attended, cost) and send it the next morning for signature, as the contract's emergency exception allows |
| Subcontractor's quote lists exclusions: scaffold and disposal | The model copies the headline price and skips the small print | List each exclusion as its own line or note, and ask the subcontractor to confirm before you send |
The conflicting-instructions case is where AI is most useful as a clerk. Ask it to turn the thread into a decision log, a short table you keep with the project file:
| Date | From | Instruction | Status |
|---|---|---|---|
| Monday | Client | Tile A, matt white, 4 x 12 | Superseded |
| Wednesday | Client | Tile B, grey, 3 x 6 | Latest; awaiting confirmation |
| Wednesday | You | Asked client to confirm tile B in writing | Open |
Nothing gets priced until the status column shows a final instruction. That one habit prevents the most expensive kind of change order, the one for work the client never meant to order. For worked examples from single trades, see the plumbing change orders tutorial.
The review pass before anything reaches the client
The AI drafts and you review, so make the review a fixed routine of about ten minutes rather than a glance. Nine checks, in this order:
- Scope: does each line match what the messages and photos show, and nothing more?
- Source: can every price be traced to a rate-sheet code or a pasted subcontractor quote, and is every TBC resolved or removed?
- Markup: applied as the contract says, and kept off credits unless the contract says otherwise?
- Arithmetic: redone in your own spreadsheet, not only in the chat.
- Schedule: stated in working days, with the assumption visible?
- Exclusions: any subcontractor exclusions listed as lines or notes?
- Identity: project, change order number, date and parties correct?
- Approval: signer, form and response period matching the change clause?
- Overlap: does an earlier change order already cover any line?
A second-pass prompt helps with the arithmetic: "Recompute every total in this change order from the lines shown, and list any figure that differs from mine." It catches slips quickly, but the check that counts is the one in your spreadsheet, because a model can repeat a slip while confirming it.
Getting it signed, chased and logged
Send the finished change order as a PDF through your e-signature tool or, if you run construction software, from the software itself. JobTread, for example, builds change order cost items from the job budget, lets customers approve digitally and tracks approvals back to the budget, so there the AI's job is the wording rather than the numbers; its AI Writing Assistant drafts and rewrites project communications. Whichever route you use, work in the changed area waits for the signature unless the contract's emergency exception applies. A text thread isn't the approval, and a lawyer can tell you whether a text or email reply satisfies your contract's wording.
When the response period runs out, chase with a short message that names the number, the amount and what is waiting:
Hi [first name], following up on change order CO-03 sent on Wednesday (net +$507.25, one extra working day). The floor repair is waiting on your signature before we can close up the area, and the contract asks for a reply within two business days. Can you approve it today? [Your name]
Then log it. A change order log is a spreadsheet with one row per change, and it answers the client's favourite question, "where are we now?", in one glance:
| CO | Raised | Description | Net amount | Days | Status |
|---|---|---|---|---|---|
| CO-01 | Week 2 | Move socket to island wall | $212.50 | 0 | Approved |
| CO-02 | Week 3 | Upgrade tap to client's choice | $96.00 | 0 | Approved |
| CO-03 | Week 4 | Subfloor patch, lighting, crown credit | $507.25 | 1 | Awaiting signature |
Approved changes total $308.50, and CO-03 would bring the contract to $48,500 + $815.75 = $49,315.75 with one extra day. Ask the project to turn the log into three lines for each weekly client update: approved total, awaiting signature, and schedule days added. The construction final account tutorial shows where those lines end up when the job closes.
Setting it up in an hour, and where it goes wrong
Set the routine up once, in a ChatGPT or Claude project named for change orders rather than for any one client:
- Add the change rules table, the full rate sheet and a one-page change order layout. ChatGPT projects hold a limited number of files depending on the plan (five on Free, 25 on Go and Plus), so keep those three as three files.
- Paste the standing instruction from the worked example as the project's instruction.
- For each job, open a new chat inside the project and paste only that job's messages, captions and quotes.
- Test with three past changes where you already know the right answer, and compare every figure.
Expect about an hour for the first setup, and a few minutes of tidying the rate sheet whenever your costs move. Then watch for the failure patterns below, each of which has a way to spot it:
- Prices from memory. Any line without a rate code or a quote reference is suspect. The TBC rule is the cure.
- Double markup. If the rate sheet holds cost rates, the draft should mark up once. Test it with a credit, as the worked example did.
- Loose scope wording. Phrases such as "all necessary work" or "full replacement" should trigger a check against the message and the photo captions.
- The wrong job's messages. A new chat per job, and the project name on every draft, keeps threads apart.
- Client data in the tool. Placeholders for names and addresses, and a look at the plan's data settings. On a personal plan, turn off the setting that lets the provider use your chats for training.
- Photos misread. Treat the model's description of a photo as a hint, and let your own caption win.
- Starting before signature. The log's status column should show Approved before anyone is told to proceed, unless the emergency exception applies.
Used this way the AI is a fast, tidy clerk with no authority: it assembles what you have, applies your rules and flags what it doesn't know. The authority stays with the contract, your rate sheet and your signature. If you'd like help fitting the routine to your own contract and job software, my AI implementation consultation is built for that.
Questions contractors ask about AI-drafted change orders
Is a client's text enough to start the work?
Treat it as evidence of the request, not as approval. Most contracts set out how changes must be approved, often in writing and signed before work starts. Check your change clause, and ask a lawyer whether a text or email reply meets it. Emergency work is the usual exception, and it should be recorded and signed afterwards as the contract allows.
Can AI price the change order?
It can multiply and add, but only from the rates you give it. Put your rate sheet and markup rules in the project, tell the model to use only those lines and to mark anything else TBC, then check every total yourself. A price from the model's memory is a guess, however confident it sounds.
What if the client keeps adding small changes?
Log each one the day it is asked, even if it seems minor, and batch the written change orders weekly so no single request drags. Some contracts set a threshold below which an email approval is enough, so check yours. The running total also gives you something concrete to show the client in the weekly update.
Should I paste the whole text thread into AI?
Paste only the messages about the change, with names, addresses and phone numbers replaced by placeholders. Check the tool's data settings first: ChatGPT Business and Claude Team leave your content out of model training by default, and personal plans let you switch training off in the privacy settings.
Further reads
- Electrical Change Orders Written With AI: Ask for Extra Work Clearly — Wording that asks for extra payment clearly, from an electrical contractor's view.
- AI Tools for Contracting Businesses: Subcontracts and Change Orders — Tools that handle subcontracts and change orders together.
- Which AI Tools Should a General Contractor Buy? What to Skip — Which AI tools a general contractor should buy and which to skip.
- JobTread Pricing for a Five-Person Builder: What You Pay and What AI Adds — What a five-person builder pays for JobTread and what its AI adds.
- Writing Client Updates and Snag Lists With AI for Builders — Weekly client updates that carry the change-order log.
- Painting Contract Template: Colour Approval and Change Orders With AI — How another trade drafts change-order terms into its contract.
- AI Construction Contract Review Software: What Builders Should Test — What to test when software reads your construction contract.
- AI Assistant for Contractors: ChatGPT, Claude and Gemini on Real Jobs — One bathroom refit, three jobs: quote lines, a scope of works and a tricky client email, run the same way through ChatGPT, Claude and Gemini.
- AI Automation for Construction Companies: Daily Logs to Invoices — Six paperwork steps from dictated daily log to progress invoice, one tool each, with a ten-person firm's costs, sums and who signs what.
- AI Tools for Construction Project Management: RFIs, Logs, Reports — One eight-week fit-out followed through its daily logs, RFIs and weekly client reports: which tools do each job, what they cost and what you must still check.
- ChatGPT for Builders: Ten Prompts for Quotes, Chasers and Client Emails — Ten copy-and-paste ChatGPT prompts for domestic builders, from scope notes to overdue chasers and handover emails, with sample replies and what to fix.
- ChatGPT for General Contractors: 10 Prompts for Bids, Subs and Updates — Ten prompts for bid screening, scope sheets, sub chasing and client updates, each with a sample output and a check before sending.
- Custom Home Builder Proposal: Draft Allowances and Exclusions With AI — Draft a custom home proposal in ChatGPT or Claude: allowance table, exclusions in full sentences, payment stages that match the work, and pre-send checks.
- Fence Contract Template: Draft With AI, Add Permit and Boundary Clauses — Drafting prompts for the permit, boundary, utility, weather and payment clauses of a fence contract, with the mistakes to fix and a lawyer-ready pack.
- How Can AI Help General Contractors? Ten Jobs, Ranked by Effort — Ten jobs for a small contractor in three effort tiers, each with a worked example and the check that keeps a person in charge of the result.
- How to Use AI as a General Contractor: Four Weeks, Four Jobs — A four-week start for a general contractor: documents, site notes, bid comparison and review, with plan costs, owner hours and checks for each job.
- Lien Waivers for Small Contractors: Track Conditional and Final Releases — A three-tab sheet that matches each conditional and final lien waiver to the payment it covers, with red-flag formulas and a worked HVAC example.
- AI Tools and AI Development: The Complete 2026 Guide — the AI hub, including every tutorial in the AI-for-business series.
Sources: JobTread change order and AI feature pages, OpenAI and Anthropic help pages on image inputs and projects. Contract wording, rates and prices in the examples are illustrative.