How Does a Subcontractor Write a Change Order Request?

A change order request (some contracts say change order proposal or potential change order) is your offer to do changed work for a price and a number of days. It is not a change to your subcontract until someone with authority signs it. Until then, the work may be at your own risk.

On most commercial jobs the request runs up the chain. You send it to the GC; the GC reviews it, adds its own markup and sends it to the owner (often through the architect); the owner signs a change order with the GC; and the GC then signs a matching change to your subcontract. AIA publishes a contractor–subcontractor version of its change order form for that last step (G701S), which, once executed, indicates agreement on the change in price and time.

The deadline that loses most changes is notice, not price. The federal changes clause is a clear example: no adjustment is made for costs incurred more than 20 days before the contractor gives written notice of a constructive change, and the contractor must assert its right to an adjustment within 30 days of a written change order (FAR 52.243-4). Private subcontracts set their own periods, and a subcontract often gives the sub less time than the prime contract gives the GC, so the GC can meet its own deadline.

Notice can be short: the date, what happened, who directed it, and that you consider it a change and will price it. Send it in writing, keep a copy, and keep working only as your subcontract directs.

If the request answers an RFI, name the RFI number and quote the answer. It is the fastest way to show the work is a change and not something already in your scope.

Build the price in groups the GC can compare line by line, the same way it prices its own change orders. Labor is hours by trade times the burdened rate (base wage plus payroll taxes, insurance, benefits and fringes, from your payroll records). Materials are quantities times supplier prices, plus tax and delivery. Equipment is the rental invoice or your company's rates.

Then add only the markup your subcontract allows, once. Public specifications show how fixed these can be: Caltrans' force-account rules, for example, add 35% to labor (after a labor surcharge), 15% to materials and equipment, and 10% to subcontracted work (Caltrans payment module). Expect the GC to add its own markup on your total, at the rate its prime contract allows for subcontracted work; that is not double-counting, because it covers the GC managing your change.

To check the arithmetic, run your numbers through the change order pricing calculator: put your own work in the labor, materials and equipment fields and your markup in the own-work rate.

The job is fictional: "Alder Street Medical Office". The owner adds two hand sinks in exam rooms after the walls are framed and rough-in is done, by an owner's directive the architect issues as a bulletin. A fictional plumbing sub, "Copperline Plumbing", gives written notice the next day and prices it. Its fictional subcontract allows 15% overhead and profit on its own work.

Each line is rounded to the cent where shown. If the GC's prime contract allows 5% on subcontracted work, it would add $179.06 (5% × $3,581.27 = $179.0635) and carry $3,760.33 to the owner, before any insurance or bond the prime contract allows.

• Late notice: the work was done before anyone was told, and the contract's notice period ran out.
• In scope already: the drawings or specs showed the work; quote the document that did not.
• A lump sum with no breakdown: the GC cannot defend a number it cannot check.
• Markup above the contract's rate, or markup on markup.
• No days, or days with no reason they affect the schedule.
• No backup: quotes and crew hours are the first thing the owner asks for.

Once the change is signed, bill it as its own line on your pay application, and remember that retainage is usually held on it like the rest of your contract.

In Conflo a subcontractor can write a change order for its own scope: a title, the reason (RFI, owner request, field condition or design error), the RFI it came from, priced lines with cost codes, the schedule days and a due date. The sub's lines are its quote, its cost for the work. It goes to the GC's review, where the GC sets its markup, then to the owner for approval.

The sub sees its own quote, never the GC's markup or the owner price. A Files section is shared with everyone on the change order, and a Cost backup section is seen only by the GC and that sub. Once the owner approves, the quote is added to the sub's commitment at its cost and the change flows into pay apps. Limits today: lines are amounts, without separate fields for labor hours, materials or equipment, and the sub cannot set a markup of its own; put your overhead and profit in the line amounts.

A change order request that gets signed is sent early and reads like an estimate: notice in writing, the cause and its document, scope in plain words, direct cost by group, the contract's markup applied once, days with a reason, and backup. Leave the GC nothing to rebuild.

Read your subcontract's changes article and notice period before the first change arrives, and write every request the same way.

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1. FAR 52.243-4, Changes — Acquisition.gov, U.S. General Services Administration. Read October 16, 2026.
2. Local Assistance Module 8: Payment (January 2026), force account under Standard Specifications 9-1.04 — California Department of Transportation (Caltrans). Read October 16, 2026.
3. Summary: G701S–2017, Change Order, Contractor-Subcontractor Version — AIA Contract Documents. Read October 16, 2026.