How Contractor Change Orders Really Work

A signed contract with a fixed price feels like the end of the cost conversation. On a renovation it is closer to the beginning, because change orders are the mechanism by which that fixed price legitimately moves — and the clause governing them is usually the least-read paragraph in the whole document.

Getting it right before work starts is worth more than negotiating the price.

What change orders actually are

A change order is a written amendment to the contract: a change in scope, a change in price, sometimes a change in schedule, agreed by both parties.

They arise from three quite different situations, and the distinction matters because it determines who should reasonably bear the cost.

Owner-requested changes. You decide mid-project to move a wall, upgrade the tile, add a circuit. Entirely your cost, and entirely fair.

Concealed conditions. The wall comes open and there is knob-and-tube wiring, rot, asbestos, or a beam nobody knew carried load. Nobody could have priced it in advance. This is what change orders exist for and it is normal on any older house.

Scope the contractor missed. They did not price something the job always required. This is the contentious category, and whether it becomes a change order depends almost entirely on how specific the original scope document was.

The third category is where disputes live, and it is why an explicit exclusions list in the estimate matters so much. The contractor estimate guide covers what that document should contain.

The clause that controls everything

Before signing, the contract should say four things about changes.

Written approval before work proceeds. No verbal authorisations. A conversation on site is not a change order, and "you said go ahead" is not a document.

How changes are priced. Either cost plus a stated markup percentage, an agreed hourly rate for labour plus materials at cost, or a published schedule. Without this, changes get priced after the work is done, which is the weakest possible position to negotiate from.

Schedule impact stated. A change that adds two days should say so. Otherwise the completion date quietly becomes unenforceable.

A cap or notification threshold. Some contracts require the owner's approval above a stated amount, which prevents an accumulation of small changes nobody tracked.

That clause costs nothing to negotiate before signing and is effectively impossible to negotiate after.

Why renovation carries more of them than new build

New construction happens on a known site to a known design. Renovation happens inside a building whose history nobody documented.

The realistic planning figure is a contingency of 10 to 20 percent on renovation work, more on anything older or where systems are being touched. A project budgeted to the exact contract price has no room for the first genuine surprise, and there is almost always a first genuine surprise.

Treating that contingency as a separate, visible line rather than hoping the quote holds is the difference between a manageable overrun and a stalled job. The crew hours guide covers the same discipline from the contractor's side of the table.

The pricing asymmetry

Here is why change orders cost more per unit of work than the original contract did, and why that is partly legitimate.

At bid stage the contractor is competing. Mid-project they are not. There is no second quote for moving one outlet in a room that is already open, and both sides know it.

There is also real inefficiency in a change. Work already done may have to be undone. Material may be ordered in small quantities at worse prices. The crew may be pulled off a planned sequence. A change that would have cost $500 if included in the original scope genuinely can cost $900 as an interruption.

What is not legitimate is a markup that bears no relation to either — which is exactly what the pricing clause prevents.

Keeping track as they accumulate

The failure mode is not one large change order. It is eleven small ones that nobody totalled.

Keep a running log with the date, what changed, why, the agreed price and the schedule impact. Ask for the revised contract total on every change order rather than just the increment, so the current number is always visible.

If a contractor resists writing changes down for small items — "we'll sort it at the end" — that is the moment to insist. Sorting it at the end means receiving a number you cannot verify against work you can no longer inspect.

Reducing them before they happen

Most change orders on a well-run job are avoidable, and they are avoided before anything is demolished.

Decide your selections early. Every undecided item is an allowance, and every allowance is a future adjustment. The contractor allowance guide covers how to price them realistically up front.

Investigate what you can. Opening a small inspection hole, pulling a permit-history record, or having an electrician look at the panel before bidding converts an unknown into a priced item.

Get the scope specific. Vague scope is what turns missed work into a negotiation. "Update the bathroom" is not a scope; a fixture list, a tile schedule and a note about who patches the ceiling is.

Ask what typically comes up. A contractor who has done twenty of these knows the three things that usually appear. That answer is free and it is the most useful thing you will hear during the bidding process.

Where this fits in choosing a bid

Change-order behaviour is a reason to weigh bids on more than price, because a low number with a weak change clause is not a low number.

Ask each bidder how they price changes and what their last three jobs came in at against contract. A contractor who tracks that and will tell you is a different proposition from one who has never thought about it.

The bid comparison calculator levels the quoted scope so the starting point is honest, and the lowest bid guide covers why an underbid so reliably reappears through this route. For consumer guidance on contract terms, deposits and dispute resolution, the Federal Trade Commission publishes a short checklist worth reading before signing.