Why Most Contractors Lose Money on Change Orders
Ask any honest contractor where their margin actually lives and they'll point at change orders. Then ask them what their average change order margin is and watch their face. The "profitable" line item is run at break-even on most jobs, and it's not because the math is hard. It's because the bid didn't set it up to be profitable.
What goes wrong
The classic failure: the customer asks for a change in the middle of the job. The contractor scribbles a number on a notepad, drops it in front of the customer, gets a verbal OK, and does the work. Three weeks later when the invoice goes out, the conversation goes one of two ways:
- The customer pushes back on the number because they don't remember agreeing to it.
- The contractor remembered to bill the material but not the labor reshuffling. The crew sat for an hour while the order changed. That hour shows up on payroll but not on the invoice.
Either way, the change order that should have been the most profitable hour of the project ran at 30% margin instead of 60%.
The contract clause that fixes it
A working contractor's change-order clause:
Any change to the agreed scope of work requires a written Change Order signed by both parties before work begins. Change Orders are billed at a 40% gross margin, with a $250 minimum per occurrence to cover crew re-sequencing.
Four lines. Three things that matter:
- Written + signed before work begins. Verbal change orders are how change orders run at break-even. A written CO is a memory, a price, and a signature, in that order.
- Stated margin. 40% isn't a luxury number on a change. It's the floor, because the disruption cost is real and the spec-creep risk is real.
- Minimum charge. The $250 minimum stops the "while you're here, can you also..." conversation from costing the contractor a half day at zero margin.
Why the math should be different
A change order is more expensive to execute than the same scope at original bid because:
- The crew is mid-task and has to context-switch
- The material is a separate order, separate delivery, separate handling
- The accounting and billing carry incremental overhead
- The customer's expectations are higher because the contractor is "right there"
A 40% margin on a change isn't gouging. It's pricing the disruption honestly.
The Estimate.Pro change-order flow
Inside Estimate.Pro, every project carries a change-order workflow — the contractor selects scope additions from the trade template, the engine prices them at the project's change-order margin (defaults to 40%, configurable per customer), and renders a one-page change order that gets signed in the field. The bid line items, the markup math, and the contract clauses all carry forward from the original bid. No re-pricing. No napkin math.
The bottom line
Change orders are not the place to be generous. The contractor who runs change orders at the same margin as the original bid is the contractor who works for free on the customer's scope creep. Put the clause in writing, set the margin, charge the minimum, and the change order goes back to being the most profitable hour of the project.