How Does a GC Review a Sub's Change Order Request?

A subcontractor's change order request is a proposal, not a change. The GC is the only party who can test it against both contracts: the subcontract the sub signed and the prime contract with the owner. If you pass a weak request up the chain, the owner or architect will cut it, and you either absorb the difference or go back to the sub weeks later. Reviewing it properly once is faster than arguing it twice.

The review has two halves. Entitlement asks whether the sub is owed anything at all. Quantum asks how much. Settle entitlement first; pricing work that is already in the sub's scope wastes everyone's time. Where this fits in the rest of the job is in the general contractor's guide and the project lifecycle.

Read the cause the sub cites (an RFI answer, a bulletin, an owner direction, a field condition) and then read the sub's scope: the subcontract's scope article, its exhibits, the drawings and specification sections it lists, and the bid it was awarded on, including exclusions. If the drawings showed the work, it is not a change, however reasonable the request looks.

Then check notice. Your subcontract sets the period, and it usually points at the prime contract's. The federal changes clause shows why the dates matter: except for defective specifications, no adjustment is made for costs incurred more than 20 days before the contractor gives written notice of a change by direction, and the contractor must assert its right to an adjustment within 30 days of a written change order or of its notice, unless the Government extends the period (FAR 52.243-4, paragraphs (d) and (e)). If the sub's notice was late, you may be late with the owner too.

Where your contract sets no markup, a public agency's published rates are a reasonable reference. 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). The method you are checking against is in how to price a change order; the change order pricing calculator rebuilds a request's total from its groups in a minute.

The job is fictional: "Halvorsen Office Fit-Out". The architect's bulletin 6 adds eight dedicated circuits for a new copy room. A fictional electrical sub, "Brightline Electric", gave written notice four days after the bulletin and sent change order request 011. Its fictional subcontract allows 15% overhead and profit on its own work and a labor rate of $96.50 an hour.

The arithmetic: $2,702.00 + $2,316.55 + $385.00 = $5,403.55, and $5,403.55 + $810.53 = $6,214.08. If the fictional prime contract allows the GC 5% on subcontracted work, the GC adds $310.70 (5% × $6,214.08 = $310.704) and carries $6,524.78 to the owner.

• If you change a number, say which line, by how much and why, with the document that supports you. A bare lower number starts an argument; a reason ends one.
• If the work is not a change, say so early and cite the drawing or specification section, so the sub can respond before it prices more.
• Keep the sub's backup with the change order. The owner will ask you for it, and you cannot defend a number you cannot show.
• Once the owner signs, issue the matching change to the subcontract promptly, so the sub can bill it on its next pay application.

AIA publishes a contractor–subcontractor change order form for that last step (G701S); once executed, it indicates agreement on the change's terms, including the change in price and time. How the sub then bills the change is in how a subcontractor fills out a pay application.

In Conflo a subcontractor sends its change order to the GC person it picks, and the GC's project manager takes it over. The GC reviewer can edit the sub's lines, set the markup (0% to 50%, taken once on the total cost) and send it to the owner approvers they pick, or send it back with a reason, which is required. The owner never sees a quote the GC sent back.

The sub sees its own cost, never the GC's markup or the owner's price. The owner sees each line at the owner's price, with the markup spread across the lines and no cost codes. Cost backup is seen only by the GC and that sub. When the owner approves, the change order is executed: its cost goes into the budget's approved changes by cost code, and the sub's cost shows as an approved change order on its commitment. Limits today: a line is a cost code, a description and one amount, without separate fields for hours, rates or equipment.

Review a sub's change order request in the owner's order: entitlement, notice, scope, then each priced group against something you can see, with the subcontract's markup applied once. Write down every adjustment and its reason.

A request checked this way usually goes to the owner once, and the sub knows exactly what it can bill.

See how change orders work in Conflo

1. FAR 52.243-4, Changes — Acquisition.gov, U.S. General Services Administration. Read October 22, 2026.
2. Local Assistance Module 8: Payment (January 2026), force account under Standard Specifications 9-1.04 — California Department of Transportation (Caltrans). Read October 22, 2026.
3. Summary: G701S–2017, Change Order, Contractor-Subcontractor Version — AIA Contract Documents. Read October 22, 2026.