What Should Be in a Builder's Quote? Complete Checklist

Before anything else, a builder's quote should contain their full business details: company name, registered address, company number (if limited), VAT number (if registered), and insurance details. Without these, you have no recourse if things go wrong. A verbal quote or a handwritten note on headed paper is not sufficient for any project over a few hundred pounds.

The quote should also include your name, the property address, and a clear description of the project scope. This description should be specific enough to remove ambiguity — 'build a kitchen extension' is not the same as 'build a 25m² single-storey rear extension with bi-fold doors, underfloor heating, and a fully fitted kitchen to specification attached'.

Some warning signs in a builder's quote should make you pause before accepting. A quote with no breakdown — just a single lump sum — is the biggest red flag. Without itemisation, you can't verify the pricing, negotiate specific elements, or hold the builder to what was agreed if they cut corners.

Watch out for vague language like 'allowances' without specified amounts, 'PC sums' (prime cost sums) that are unrealistically low, or phrases like 'works as necessary' that give the builder carte blanche to charge extra. Provisional sums should be clearly labelled with a reasonable estimate, and you should agree on how any difference will be handled.

Be cautious of quotes that arrive suspiciously quickly after a site visit. A detailed quote for a £50,000 extension takes time to prepare — pricing each trade, sourcing material costs, and calculating labour. If it arrives within hours, it's likely a rough estimate dressed up as a quote.

The most common omissions are the items that cause the most disputes. Scaffolding is frequently excluded or underpriced. Skip hire and waste removal costs add up quickly — a typical extension generates 6-10 skips at £250-£400 each. Temporary works like propping, weatherproofing, and site protection are often assumed rather than priced.

Building Control fees and inspections are almost always excluded but rarely flagged. The same goes for party wall surveyor fees if you're building near a boundary. Utility disconnections and reconnections (especially gas and drainage) are another frequent omission that can add £1,000-£3,000 to the bill.

Internal decoration is commonly excluded from building quotes — builders expect you to paint and decorate after they finish. If you want the builder to handle decoration, make sure it's explicitly included with a specification (two coats of emulsion, primer plus gloss on woodwork, etc.).

Getting three quotes is standard advice, but comparing them is only meaningful if each builder has priced the same scope of work. Before inviting quotes, prepare a written specification or brief describing exactly what you want. Include drawings if you have them — even rough sketches help ensure each builder prices the same project.

When comparing, create a simple spreadsheet listing each element and each builder's price. This reveals where one builder is significantly higher or lower on specific items. A builder who is cheap on groundworks but expensive on electrical may be cross-subsidising — or may have more realistic groundwork costs and less experience with electrics.

Don't automatically choose the cheapest quote. The cheapest builder may have missed items, underestimated the complexity, or be planning to make up the difference with variations during the build. The middle quote is often the most realistic, but what matters most is the detail and completeness of the quote rather than the total figure.