How to Write a Construction Quote
A good quote wins the job and prevents the argument at the end. The difference is in the detail — what is included, what is not, and what happens when the scope changes.
Most disputes on building jobs are not really about money — they are about what the price was supposed to cover. A vague quote leaves that open to interpretation, and interpretation always drifts in the customer's favour once the work is done.
This guide covers writing a construction quote that both wins the work and protects you: the difference between a quote and an estimate, what a proper quote must include, how to handle the unknowns, and the terms that keep the job out of dispute.
Key takeaways
- A quote is a fixed price you commit to; an estimate is an indicative figure that can change — never confuse the two.
- Spell out inclusions and exclusions explicitly; the exclusions protect you as much as the inclusions sell the job.
- Use provisional and PC sums for work you cannot yet price precisely, and label them clearly.
- Set out a payment schedule tied to stages so cash flow matches the work.
- State how variations are priced and agreed, so changes become paid extras rather than free work.
Quote vs estimate — get the word right
A quote is a fixed price you are contractually committing to; if you quote £12,000 and it costs you more, that is your problem. An estimate is your best indication of the likely cost, which can move as the job reveals itself. The words carry legal weight, so use the one you actually mean and say so on the document.
For a well-defined job you can quote confidently. For genuinely uncertain work — an old building, an unknown structure — an estimate, or a quote with clearly labelled provisional sums, is the honest and safer choice.
What to include
A quote that wins and protects you states the scope of work in plain terms, an itemised or clearly staged price, and — critically — what is excluded. Exclusions are where builders get caught: if the quote does not say 'making good decorations excluded' or 'skip hire not included', the customer will assume it was in the price.
Include the basis you priced on — access assumed, existing services usable, no asbestos, and so on — plus your validity period (prices move), the programme, and your terms. The clearer the document, the fewer arguments later.
Exclusions protect your margin
Every line you exclude is an argument you have already won. Spell out what is not in the price — making good, decoration, specialist surveys, unknown structural work — so anything extra is a paid variation, not an assumption.
Provisional sums and the unknowns
When you cannot see the whole job — the state of the roof timbers, what is under the floor — do not either gamble on a fixed price or pad it heavily. Use a provisional sum: an allowance for that specific element, clearly labelled, to be adjusted to the actual cost once it is exposed. Prime cost (PC) sums do the same for customer-chosen supplies.
This keeps your headline price competitive while being honest that one element is an allowance, not a commitment. Customers accept a labelled provisional sum far more readily than a surprise bill at the end.
Payments, variations and terms
Set out a payment schedule that matches the work — a deposit for materials, stage payments at agreed milestones, and a final balance on completion, so you are never funding someone else's building work for weeks. State your payment terms and what happens if payment is late.
Above all, say how variations are handled: that any change to the scope is priced and agreed in writing before it is carried out. That single clause is what turns 'while you're here, could you just…' into a paid extra instead of goodwill you never get back.
Quote, sign and vary in one place
With TradePlanr you send a professional quote the customer signs digitally, then capture any change as a signed variation and convert the lot to a staged invoice — the whole paper trail lives on the job.
Frequently asked questions
What is the difference between a quote and an estimate?
A quote is a fixed price you commit to; an estimate is an indicative figure that can change as the job develops. The distinction has legal weight, so use the correct term and state clearly which you are giving.
What is a provisional sum?
A provisional sum is a labelled allowance for an element you cannot price precisely yet — such as unknown structural repairs — adjusted to the actual cost once the work is exposed. It keeps your price honest without gambling on a fixed figure.
How do I stop scope creep?
State on the quote that any variation is priced and agreed in writing before it is carried out, and list your exclusions clearly. That turns extra requests into paid variations rather than free work.
From guidance to action
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