Guide · California home improvement
Change orders: signed before the work starts
"While we're in here, we should..." Surprises behind walls are normal. Whether one becomes a fair price change or an argument at the end of the job depends on one thing: whether it was written down and signed before the work happened.
What California law requires
A change order becomes part of a home improvement contract "only if it is in writing and signed by the parties prior to the commencement of any work covered by a change order" (BPC 7159(c)(5)). The same section requires the contract and any changes to it to be in writing and signed (7159(d)).
Not written up at the end of the week. Not a handshake and a texted number. Signed by both of you, before that work starts.
Three things every change order states
The note every contract must carry spells them out (7159(d)(13)):
- The scope: what extra or changed work is being done.
- The cost: the amount added to or subtracted from the contract.
- The effect: what it does to the schedule of progress payments. The notice in 7159(e)(3) adds the completion date.
The third is the one people skip. A $4,000 change order that does not say which payment it lands in is a future argument.
"No signed change order means free work"? Not quite
The notice in every contract says extra work "is not enforceable against a buyer" unless the change order identifies the scope, the amount and the effect in writing before the work starts (7159(e)(3)). It also says you may not require the contractor to do extra work without giving written authorization first.
But the same notice says the contractor's failure "does not preclude the recovery of compensation for work performed based upon legal or equitable remedies designed to prevent unjust enrichment." In plain words: if they built something of value for you, a court may still have you pay for it. The paperwork rule protects you from surprise bills; it does not make extras free. If work is about to go ahead without paper, pause it until the change order exists.
A change order you can copy
Change Order #__ · Date: ______
Work: ______________________________
Price: + / − $______ New contract total: $______
Effect on the payment schedule and completion date: ______________________________
Owner signature and date: __________ Contractor signature and date: __________
Print a few blank copies when you sign the contract and keep them in the job folder.
Three habits that keep changes clean
- Price before yes. "Please write it up as a change order" is a complete answer. Never approve work without a number.
- Number them. CO #1, #2, #3: a numbered trail makes the final accounting simple.
- Recalculate the schedule. After each change order, read the payment schedule again with the new total. Payments should still follow work actually done (BPC 7159.5(a)(5)); see progress payments.
Check a change order before you sign it
With Project Guard ($39 once for one project, 90 days, no renewal, refundable any time in those 90 days), paste a change order and we check that it names the work, the price and the effect on your payments or completion date, and file it with the payment it changes. The free quick check reads a quote or contract against California's contract rules, with no account needed.
General information about California law, not legal advice. Checked against the official text on November 3, 2026. Sources: BPC 7159, BPC 7159.5, CSLB home improvement contracts guide.