A proper builder's quote should include both parties' details, a written scope of work broken into stages, the specification of materials, a fixed or clearly itemised price with exclusions stated, a payment schedule tied to progress, insurance confirmation, a variation process, and a start date and duration. Anything missing should be requested in writing before you agree to proceed.
Treat the quote as the contract, because it usually becomes one
In most small and medium domestic jobs, the quote you sign and the deposit invoice you pay become the entire written contract for the job. There's rarely a separate formal building contract, especially for jobs under perhaps £30–40,000. That means everything you might later need to point to — the price, what's included, when payments fall due — has to be in that one document.
This guide goes through what a quote should include, clause by clause, so you know what a complete one looks like rather than just what to be suspicious of.
Identity and contract basics
- Full legal trading name and business address of the builder
- Company registration number if trading as a limited company
- Your name and the property address the work relates to
- Date issued and how long the price is valid
- A reference number, especially useful if the quote is revised
Scope of work broken into stages
The scope should describe the job as a sequence of stages rather than a single description. For an extension this typically runs from groundworks through structure, roofing, first fix, plastering, second fix, and decoration. For a smaller job — a bathroom, a re-roof, a driveway — the same principle applies at a smaller scale: break it into the discrete pieces of work so nothing is assumed.
Where drawings exist, the quote should reference them by revision number, because drawings get revised and a quote tied to an old version can create confusion about what was actually priced.
Specification — the materials and fittings named
- Brick, block or render type and, where relevant, a match to existing
- Window and door make, glazing type, and U-values if energy performance was discussed
- Roof covering and any insulation specification
- Named fittings for kitchens, bathrooms and sanitaryware, or a provisional sum if not yet chosen
- Flooring and finishes
- Electrical and heating specification — number of sockets, boiler make and output where agreed
Price, provisional sums and exclusions
A complete quote states the total price and shows how it's built up — even a one-line breakdown by stage is better than a single lump sum. Provisional sums (PC sums) should be marked clearly wherever an item hasn't yet been chosen, such as tiles or sanitaryware, along with the allowance included so you know what you're working with.
Just as important as what's included is what's excluded. A thorough quote states plainly what falls outside the price — scaffolding, skip hire, structural engineer's fees, party wall costs, external works, decoration beyond making good, and so on.
Payment schedule and deposit
The quote should set out how many payments there are, roughly what proportion of the total each represents, and what stage of work triggers each one. It should also state the deposit amount and explain what it covers — usually materials ordering and securing your place in the schedule, not general working capital for the business.
Variations, insurance and sign-off
- How changes to the scope get priced and agreed before work proceeds — ideally in writing, signed by both parties
- Confirmation of public liability insurance, with cover level and expiry
- Whether a workmanship warranty or insurance-backed guarantee is included
- Who arranges Building Control notification, if required
- Start date, expected duration, and what happens to the price if the start is delayed
Practical checklist
- Builder's legal name, address and company number if applicable
- Property address and date issued
- Price validity period
- Scope broken into construction stages
- Reference to current drawing revisions where relevant
- Named specification for structural materials and finishes
- Provisional sums identified with an allowance figure
- Clear statement of exclusions
- VAT treatment shown separately
- Total price and how it's built up by stage
- Payment schedule with triggers tied to progress
- Deposit amount and explanation of what it covers
- Written variation/change process
- Public liability insurance confirmation
- Guarantee or insurance-backed warranty details, if offered
- Building Control responsibility stated
- Start date and expected duration
Good and bad examples
What good looks like
A loft conversion quote that lists structural steel supply and fit, staircase, insulation, Velux windows by make, electrics with socket count, and decoration as separate line items, states a provisional sum for the en-suite sanitaryware with a stated allowance, and attaches the structural engineer's calculations already approved by Building Control.
What to push back on
A quote that simply states 'loft conversion to include staircase, en-suite and Velux windows — £38,000' with no stage breakdown, no named specification, and no mention of the structural engineer's involvement or Building Control at all.
Worked example
Illustrative example only — for illustration, not a typical or average price
| Line item | Included in fixed price? | Notes |
|---|---|---|
| Structural steel design & fit | Yes | Per approved engineer's drawing |
| Staircase supply & fit | Yes | Standard softwood, painted |
| En-suite sanitaryware | Provisional sum £1,200 | Allowance only, to be confirmed |
| Skip hire | No — excluded | Homeowner or separate invoice |
| Decoration throughout new rooms | Yes | Two coats, one colour |
Commonly missed items
- Drawing revision references, so the quote can be checked against the current design
- Named specification, leaving finishes to be argued over later
- Provisional sum allowances, so 'to be confirmed' items have no ceiling
- A written variation process
- Confirmation of who notifies Building Control
Warning signs
- The quote is a single sentence covering a large or complex job
- No specification is given for anything — everything is 'standard' or 'as discussed'
- Provisional items have no stated allowance figure
- The builder discourages you from getting the quote checked or compared
- No insurance mentioned and no certificate offered when asked
Questions to ask
- Can you show me the price broken down by stage or trade?
- Which items are provisional, and what allowance have you included for each?
- What's specifically excluded from this price?
- How will you notify me of any cost increase before it happens?
- Can I keep a copy of your insurance certificate with the quote?
When to seek professional advice
- If you're not confident reading a construction specification, ask a surveyor or architect to review the drawings and quote together
- If structural work is involved, check Building Control requirements with your local authority before work starts (gov.uk/building-regulations-approval)
- If the quote and any verbal promises seem to conflict, get the verbal points added to the written quote before signing
Official sources
Frequently asked questions
- What's a provisional sum and why does it matter?
- A provisional sum (or PC sum) is an allowance included in the price for an item you haven't chosen yet, such as tiles or sanitaryware. It matters because if your final choice costs more than the allowance, you'll be charged the difference — so check the allowance is realistic for what you actually want.
- Do I need drawings before I can get a proper quote?
- For anything beyond simple like-for-like work, yes. Without drawings, a builder is pricing from a verbal description, which tends to produce vaguer quotes with more room for disagreement later about what was actually included.
- Should the quote mention who applies for Building Control?
- It should state clearly whether the builder or you are responsible for notifying Building Control, since this affects both cost and who is accountable if inspections are missed. Confirm the requirement with your local authority (gov.uk/building-regulations-approval).
- Is it normal for a quote not to include VAT?
- It's normal for VAT to be shown separately if the builder is VAT registered — check the figure is clear either way, since a price that silently doesn't mention VAT can lead to a surprise 20% addition at invoice stage.
- What if my builder says a detailed quote isn't necessary for a small job?
- Even small jobs benefit from a short written scope and price, if only to avoid disagreement about what 'the job' actually was. It doesn't need to be lengthy, but it should exist in writing.
Builder Proof UK publishes general educational information for homeowners. It is not legal, structural, surveying, planning, electrical, gas, insurance or financial advice, and it does not replace advice from a suitably qualified professional for your specific project.