Raise a change order with proof, not argument

Record the event in correspondence and send the notice the same week, naming the event and the date it occurred. You do not need the cost yet, and waiting for it is the most common way the notice goes late.

Why: US contracts condition the entitlement itself on the notice, not merely the payment for it. The period is short, it runs from when you should have recognised the event rather than from when you finished pricing it, and it is not the same on private and federal work. Miss it and a claim that would have been paid can be gone on the date alone, so read the period out of your own contract before you need it.

Raise the variation and write it as a difference: what the contract documents required, what is now required instead, and which instruction, drawing revision or site condition moved it. Keep the description to the change itself and leave the pricing to the next step.

Why: A change described on its own reads as a request for more money. The same change described as a departure from a named scope item reads as a fact, and the argument moves from whether it is a change to what it costs. That is the whole move.

Pull the daily reports covering the affected days into the evidence bundle along with the instruction, the drawing revision and the photographs, and note what is missing so it can be captured now rather than looked for later.

Why: The gap you find today is one somebody can still fill. The same gap found during the final account is a hole in your case, and the only person who could have closed it left the job in the spring.

Build the cost as separate lines for labor, materials, equipment, subcontract work and the additional supervision the change caused, then apply the overhead and profit percentages the contract sets rather than a round number.

Why: A lump sum invites a lump sum counter-offer. A breakdown can only be argued line by line, and most lines are not worth arguing about, so the negotiation narrows to the one or two that are. Where the contract lets the owner direct the work before the price is agreed, this breakdown is also what the eventual settlement gets measured against.

Move the change through its stages to execution, and settle the time impact in the same document as the money: either an agreed extension, or an explicit reservation where the delay cannot be assessed yet.

Why: A change order that settles the cost and stays silent on time is usually read later as having settled both. If the schedule effect is not yet knowable, saying so in the document is what keeps it open.

Let the executed change orders adjust the contract sum so the next payment application bills them as their own lines, with the work completed to date against each one, rather than folding them into the original scope lines.

Why: A change buried inside an original line is a change that gets questioned every month for the rest of the job. Billed as its own line against its own executed change order, it is approved once and stops coming up.