A change order is a written agreement between the owner and the contractor that changes the construction contract after it has been signed: it adds, removes or alters work, and adjusts the contract price, the completion date, or both. Once signed by both parties (and usually the architect), it becomes part of the contract. Change orders typically start from a design change, an unforeseen site condition, an owner request, or an answer to an RFI that turns out to change the scope.
What a change order contains
| Field | What goes in it |
|---|---|
| Change order number | Sequential per contract, for example CO-007 |
| Project and contract | Project name, contract reference, parties |
| Description of the change | Exactly what work is added, removed or changed |
| Reason | Owner request, design change, site condition, RFI reference |
| Supporting documents | Revised drawings with their revision codes, sketches, specification changes |
| Cost | The agreed amount added or deducted, with the breakdown |
| Time | Days added to or removed from the contract time |
| New contract sum and date | The running totals after this change |
| Signatures | Owner, contractor and, under most standard contracts, the architect |
How the change order process works
- A change is identified: through an owner request, a design revision, an RFI answer or a site condition.
- The architect issues a proposal request (or the contractor raises a change request), describing the change with drawings.
- The contractor prices it: cost and time impact, with subcontractor quotes.
- Negotiation: the architect or cost consultant reviews the price.
- The change order is signed by owner, contractor and architect, and the contract sum and time are updated.
- Revised drawings are issued for construction with clouds and a new revision in the revision block.
Change order vs RFI vs construction change directive
| RFI | Change order | Construction change directive | |
|---|---|---|---|
| Purpose | Ask for clarification | Agree a change with its cost and time | Order a change before the price is agreed |
| Changes the contract? | No | Yes | Yes, price settled later |
| Signed by | Answered by the design team | Owner, contractor, architect | Owner and architect |
More on RFIs in what is an RFI in construction.
How to keep change orders under control
- Describe the change precisely and attach the drawings that show it; "revised layout" invites disputes.
- Price changes before the work is done whenever possible.
- Keep a change order log with status, amount and time for every item.
- Show the change on the drawings: compare the revised sheet against the contract sheet so both sides see exactly what moved. In Ncored, the PDF editor we built in our architecture studio, you drop the contract revision onto the new one and see additions in blue and removals in red, on Windows and Mac. See how to compare two PDF files.
Frequently asked questions
What is a change order in construction?
A signed amendment to the construction contract that changes the work and adjusts the contract price, time, or both.
Who approves a change order?
The owner and the contractor sign it; under most standard contracts the architect signs it too.
What causes most change orders?
Owner-requested changes, design errors or omissions, and unforeseen site conditions are the most common causes.
Is a change order the same as a variation?
Broadly, yes. "Variation" is the usual term in the UK, Australia and many other countries; "change order" is the US term.
Related: what is a transmittal, types of construction documents, what is a punch list.