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Change Orders in Construction: How Subs Get Paid for Extra Work

Last updated: March 20, 2026

TLDR

A change order documents a scope addition or reduction to an existing contract — it authorizes the extra work, adjusts the contract price, and extends or compresses the schedule. Specialty trade subs lose hundreds of thousands per year on undocumented change order work. Every verbal instruction to do extra work needs a written change order before work starts.

DEFINITION

change order
A written amendment to the original contract authorizing scope/cost/schedule changes.

DEFINITION

constructive change
An owner or GC directive that changes the scope without a formal change order — creates a claim situation if undocumented.

DEFINITION

claim
A formal demand for compensation for work outside the original contract scope, typically filed when change orders are denied.

DEFINITION

back-charge
A deduction from your payment for costs the GC claims you caused — often disputed, always in writing.
“Every time a GC says 'just do it and we'll handle the paperwork later,' that's $5,000 I'll probably never see. I've trained my foremen to stop work and call the office before touching anything outside the drawings.”
A. Reyes , Owner at Reyes Electrical
“We started requiring written authorization before any extra work — even a text message — and our change order collection rate went from about 60% to over 90%.”
C. Brennan , Project Manager at Northgate Mechanical

Why change orders are the top reason subs don’t get paid what they earned

Most specialty trade subs are good at their trade. They are not good at change order paperwork, and that gap costs real money.

The pattern is consistent: a GC’s superintendent asks your foreman to extend a conduit run, reroute a pipe around a last-minute beam, or add receptacles that weren’t in the drawings. The foreman says sure, the crew does the work, and nobody writes anything down. Three weeks later, the pay application comes back short. The GC says they never authorized extra work. Your foreman remembers the conversation differently than the superintendent does.

That’s not a bad GC problem. That’s a documentation problem.

Every scope deviation — no matter how small, no matter how good the relationship — needs a paper trail. Not because GCs are dishonest, but because the superintendent who directed your crew and the project manager reviewing invoices are often different people with different information.

Constructive changes and verbal approvals

A constructive change is what happens when a GC directs you to do something different without issuing a formal change order. “Move the panel six feet left” is a constructive change. “Add a circuit for the new equipment” is a constructive change. These happen constantly on active jobs.

The problem isn’t the work — it’s the missing paperwork. If a constructive change adds cost to your job and you don’t document it at the time, collecting payment for it later is an uphill fight. The GC’s position is that the direction was within your original scope. Your position is that it wasn’t. Without contemporaneous documentation, it becomes a he-said/she-said argument where the person holding the checkbook usually wins.

Verbal approvals carry the same risk. A superintendent’s handshake approval means something in the field and nothing in the dispute process.

The cost estimate before the change order starts

The best time to price a change order is before the work begins.

Put together a written estimate — labor hours by classification, material quantities and costs, overhead and markup. Submit it. Get it approved. Then do the work.

Estimating after the fact forces you to reconstruct costs from timesheets and receipts that may be incomplete, and it gives the GC room to second-guess every number. An approved estimate before work starts eliminates most of that friction.

Even a rough not-to-exceed number, submitted in writing and acknowledged by the GC, is better than no estimate at all. It establishes that extra work is happening, that it has a cost, and that both parties knew about it before work started.

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Q&A

What is a change order in construction?

A change order is a written amendment to a construction contract that modifies the scope of work, adjusts the contract price, and may extend or compress the project schedule. Change orders are generated when work is added, removed, or altered after the original contract is signed. For specialty trade subcontractors, change orders are the mechanism for getting paid for anything...

Q&A

What happens if I do change order work without written approval?

You may not get paid. Work performed outside the original contract scope without an approved change order is often disputed, reduced, or rejected outright during pay applications. The GC's position is typically that they did not authorize the additional cost, even if their field personnel directed the work. Without written authorization, you are left arguing about conversations that the other...

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Can a GC refuse to sign a change order?
A GC can refuse to sign, but that refusal creates a claim situation. If the work was genuinely outside the original scope and you have documentation of the directive and the cost, you have a recoverable claim. The process: submit the change order in writing, document the GC's refusal or non-response in writing, proceed under protest if the contract requires it, and preserve your right to claim. Most subcontracts have a process for disputed change orders — read yours before the dispute happens.
How long does a GC have to approve a change order?
Your subcontract sets the timeline. Many contracts require the GC to approve or reject a change order within 7-21 days. If the contract is silent, reasonable commercial practice is typically 14-30 days. If a change order is aging without response, follow up in writing and document each attempt. Unanswered change orders are a cash flow problem — work was done, the cost is real, but billing is blocked until approval. Some subs include a provision that change orders not rejected in writing within 14 days are deemed approved.
What if the GC says 'just do it and we'll sort it out later'?
'We'll sort it out later' is the most expensive phrase in construction. When a GC says this, the right move is to slow down, not speed up. Respond in writing: confirm the scope you're about to perform, state your estimated cost, and note that you will proceed upon written authorization. If they push back on the paperwork, that's a signal they don't intend to pay full value. The work you do without authorization is work you are lending to the project — you may never recover it.

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