How to Write a Construction Change Order (With Free Template)

If you've been in the trades long enough, you've eaten the cost of extra work you didn't document. A client asks for something outside the original scope, you do it because you want to keep the relationship, and then when the bill comes they say "I didn't think that was extra."

That's not a client problem. That's a documentation problem.

A properly written change order protects you legally, keeps your cash flow predictable, and sets professional expectations with your clients. Here's exactly how to write one.

What Is a Construction Change Order?

A change order is a written amendment to your original contract. It documents any scope change — added work, deleted work, or substituted work — along with its impact on cost and schedule.

In California, under Business & Professions Code §7159, any change to a home improvement contract must be in writing and signed by both parties before work begins. Verbal agreements don't hold up in arbitration or small claims court.

What Every Change Order Needs

A professional change order should include:

Project and party identification — Contractor name, license number, phone, email. Client name and property address. Reference to the original contract date.
Description of the change — Be specific. "Additional framing" is not enough. "Add one LVL beam (4"×12"×16') to open kitchen wall per structural engineer's spec dated 3/1/2026" is defensible.
Reason for the change — Client request, design change, unforeseen condition, or engineer/architect directive.
Cost impact — Break it down: labor cost change, materials cost change, total change order amount, revised contract total.
Schedule impact — How many additional days does this add? Even if it's zero, say so.
Signature lines — Both contractor and client must sign before work begins. Date the signatures.

The Language That Protects You

Include this clause in every change order: "Work described in this Change Order will not commence until this document is signed by both parties. Contractor shall not be responsible for any delays caused by the time required to execute this Change Order."

This prevents the "just go ahead and start, we'll sign it later" situation that always ends badly.

Common Change Order Mistakes

Not getting it signed before starting work — the most common mistake. Once the work is done, your leverage disappears.
Being vague about scope — if the description is ambiguous, the client will interpret it in their favor.
Forgetting overhead and profit — your change order price should include your markup, not just direct costs.
Not referencing the original contract — your change order should explicitly reference the original contract date and amount.

The Easier Way