Valuations
Material prices went up mid-contract. Who pays the difference?
Timber jumped between your quote and the second fix, and the merchant’s new price is your problem or the client’s depending on one thing only: what the contract says. Fairness has no vote, which is why this page is half about the current job and half about the next quote.
QScope Team·25 March 2026·5 min read
The starting rule is brutal and short: a fixed price is fixed. Agreeing a lump sum means you took the risk of your input costs moving, in both directions, and a supplier’s increase is inside that risk. The client’s polite refusal to share it is not sharp practice; it is the deal.
What a fluctuations clause would have done
Standard forms offer fluctuations provisions, optional machinery that adjusts the contract sum for cost changes during the job, in flavours ranging from narrow (tax and levy changes only) to full cost indexation. They fell out of fashion in the low-inflation decades and came back the hard way when materials spiked; whether yours has one is a contract particulars question, and on most small jobs the honest answer is no, the option was never ticked. If it was: follow its machinery exactly, the notice requirements and evidence rules are conditions, not decoration.
The narrow escapes worth checking before you concede
- Was the dearer material actually a change? A specified product discontinued or unavailable, replaced by instruction with something else, is a variation valued at its real cost, not a fluctuation. The line between “the same thing got dearer” and “I was instructed to supply a different thing” is worth drawing carefully, with the correspondence.
- Was the delay that pushed you into the higher prices the client’s? If you would have bought in March at March prices but for client delay, the increase can form part of the money consequences of that delay, argued with the delay machinery, not as a price plea.
- Provisional and PC sums adjust anyway: allowances are replaced by actual costs by design, including the increase, so check which bill lines the pain actually sits in before treating it all as fixed.
- A quote that never became binding: if the price was estimate-labelled or the contract formed on other terms, the analysis changes, what actually got agreed is the first question, not the last.
Pricing the next job in a rising market
The real lesson lives in the next quote, and there are four honest tools: a shorter validity period on the quote itself (“prices held for 30 days”); a fluctuations clause proposed openly where the job is long, framed as fair in both directions because it is; early procurement of the volatile packages, bought at today’s price the week the contract signs, which may need the deposit conversation; and provisional sums for the genuinely unpriceable, labelled honestly. A homeowner will accept any of these explained in advance (section 106 makes the quote the whole framework there); what no client accepts gracefully is a fixed price that turns out to have been an opening position.
What to do this week
1. On the live job, check the four escapes against the documents before conceding the increase is yours.
2. Buy forward the volatile packages you are already committed to, today’s known price beating next quarter’s guess.
3. Fix your quote template: validity period, and a decision per job about fluctuations or early procurement.
Where the information stops
Whether your facts fit one of the escapes, particularly the change-versus-fluctuation line, is a documents question, and on an increase big enough to hurt, worth a professional read before you either concede it or build a claim on it.