Fifteen ways a fixed bid turns into an open invoice

A change order is a written amendment: scope, price, and schedule impact. Good ones are specific and signed before work starts. Bad ones arrive as a text message after the work is already done, with a number and no breakdown. The fifteen items below are the ones that show up again and again in residential renovation disputes.

The traps

1. “Allowance” treated as a price. The bid says $10,000 for cabinets, but the specification is empty. You choose $18,000 cabinets. The difference is a change order, plus markup.
2. Unpriced exclusions. “Subfloor repair by others” sounds administrative until the subfloor is rotten. Ask for a unit price per sheet before signing.
3. No unit rates for unknowns. Contractors who cannot give a rate for drywall repair, framing, or electrical discovery are telling you the price will be invented later.
4. Verbal approvals. The single most expensive sentence in renovation: “Go ahead, we'll sort it out.” If it is not in writing, it is not agreed — and the invoice will reflect the contractor's memory.
5. Markup stacked on markup. Materials marked up 20%, then the change order marked up another 15% for “administration.” Ask for one markup, stated once.
6. Change-order fees with no cap. A flat $500 processing fee per change is reasonable; 10% of every change with no ceiling is not.
7. Owner-supplied fixtures with no install price. You buy the faucet, the plumber charges two hours to fit it. Multiply by every fixture and the savings disappear.
8. Schedule impact priced only in dollars. A three-week delay costs rent, storage, or a second mortgage. Ask for the schedule impact in writing on every change.
9. “As required by code” blank checks. Code compliance is not optional, but it should be scoped. Ask which code items are already included and which are not.
10. Hidden demolition scope. The bid removes tile but not the mortar bed. Removing a 2-inch mud bed is a different job with a different dumpster.
11. Relocation clauses. Moving a drain two feet is not “minor.” Get plumbing and electrical relocation priced per fixture before demo.
12. Retroactive change orders. Work performed, then billed as a change. Refuse retroactive pricing; the contract should require written approval before work.
13. Contingency spent before it is needed. A contractor who knows there is a 20% cushion sometimes finds a way to use it. Keep the contingency in your account, not the bid.
14. Final payment before closeout. Paying the last 10% before final inspection, lien waivers, and the punch list removes every incentive to finish.
15. No written punch-list deadline. “We'll come back” is not a schedule. Put a date and a holdback amount on it.

What a change order should contain

One page is enough, but all five elements need to be there: a description of the work, the price with a breakdown (labor, material, markup), the schedule impact, the effect on the contract total, and two signatures. If the contractor resists putting it in writing, that is the answer to a different question — whether you want to keep working with them.

The final walkthrough

Walk the house room by room with a roll of blue tape and the contract's finish schedule in hand. Test everything that moves or carries water: every door, every window, every faucet, every outlet, every switch, every drain. Run the shower and the dishwasher at the same time. Open the panel and confirm the breakers are labeled.

• Doors latch without lifting; windows open and lock.
• Every outlet and switch works; GFCI and AFCI trip and reset.
• Water runs hot within a reasonable time at every fixture.
• Drains do not gurgle; the shower drains without pooling.
• Tile is level at the edges, grout lines consistent, no lippage underfoot.
• Paint is even under raking light; no holidays at corners.
• Cabinets close evenly; drawers do not rub; toe kicks are secure.
• Counter seams are where you agreed; no chips at the cutouts.
• HVAC returns are clear; the filter is new and the right size.
• Smoke and CO alarms are present, interconnected where required, and tested.
• Exterior: flashing, grading, downspouts, and the paint line at the threshold.
• Paperwork: final inspection card, warranty documents, manuals, paint colors, lien waivers.

Photograph each item you mark. The photos are what turn “it's fine” into “here is the list.” A punch list with twelve dated photos gets finished faster than a conversation.

If the number is already wrong

If you are mid-project and the change orders are already piling up, stop signing and start documenting. Ask for a written reconciliation of the contract total, approved changes, and pending changes. Compare it against the payment schedule and what has actually been completed. Most disputes are not about the work — they are about two different versions of the same spreadsheet.

For the sequencing that prevents most of these traps, read the eight stages. For the numbers behind them, use the cost estimator.