What Is a Change Order in Construction?

A change order is a written amendment to a construction contract that documents a change in scope, price, or schedule. It becomes binding once both parties sign it. Work performed without a signed change order is routinely disputed — and routinely goes unpaid.

What a change order actually does

A change order is not a request and not a notice. It is an amendment: once executed, it modifies the contract itself. A complete one adjusts three things at the same time.

• The scope of work — what you are now obligated to build
• The contract sum — what you will be paid for it
• The contract time — how many days the completion date moves

Leaving any of the three blank is a common and expensive mistake. A change order that adds work and cost but claims zero schedule impact is the document a general contractor will hand back to you months later when you file a delay claim.

When you need one

• The owner or general contractor directs work outside the original scope
• You hit an unforeseen or concealed field condition — something the drawings did not show
• The drawings contain an error or omission that has to be resolved to continue
• An inspector or code requirement forces a change discovered during construction
• The owner requests an upgrade, substitution, or a change in finish
• Another trade's delay extends your schedule and increases your cost

What a change order must contain

The details below are the ones that decide whether a change order survives a dispute. Everything else is formatting.

• Identification: change order number, date, project name, and the original contract number
• A description of the change and, critically, who directed it and when — a name and a date turn "they told us to" into evidence
• A cost breakdown by line item: labor hours, material quantities, and equipment listed separately
• Overhead and profit shown on its own line, not buried in the unit prices
• Schedule impact stated in days, even if the answer is zero
• Signature blocks for every party whose approval the contract requires

Change order vs. RFI vs. T&M tag

These three documents get used interchangeably on jobsites, and they do completely different jobs. Only one of them changes what you are owed.

Why change orders get rejected

Rejections are rarely about the money. In practice they trace back to a handful of avoidable gaps.

• No written direction — the request rests on a conversation nobody wrote down
• The scope is described too vaguely to distinguish from base contract work
• A single lump sum with no breakdown, which invites a negotiation you will lose
• Submitted after the work was already performed, or past the notice period in the contract
• Markup above the rate the contract already specifies for change order work

The cost of proceeding on a verbal promise

The single most common reason subcontractors do not get paid for extra work is that they performed it on a verbal instruction and documented it afterward, or not at all. Memory is not evidence, and the person who gave the instruction may not be on the project when the invoice is disputed.

If you are directed to proceed before a change order is signed, three things protect you: send written notice that you are proceeding under protest, keep a daily record of labor and materials on that work, and photograph the conditions before, during, and after. That paper trail is what a time and materials claim is built from.