How we price jobs

Prices for building work vary enormously, and a lot of what's published online contradicts itself. This is how we arrive at the figures on our cost guides.

Rules come from the source

Building Regulations, gas safety law, water regulations, grants and VAT reliefs are checked against the legislation on legislation.gov.uk and the official guidance on GOV.UK, HMRC and the devolved governments. Approved Documents are read in full, including which edition is in force: where a new edition has been published but isn't in force yet, we say so.

Prices are triangulated, then built up

• Published trade data, such as Checkatrade's estimator-reviewed cost guides and MyJobQuote's job data.
• Retailer shelf prices for materials and products (for example worktops, doors and showers), read on the day we check.
• Specialists' published price lists and council schedules of rates.
• Buyer surveys (Magnet, Which?) as a sense check on what people actually spend.

We never copy another site's table. Totals on our pages are built up from their parts (units, labour per unit, materials per metre), so they add up, and the calculators use exactly the same figures as the text. Where sources disagree, or contradict themselves, the page says so and explains which figure we used and why. Where a figure is our own assumption, the calculator says so.

Dates mean something

Every guide shows the date its prices and rules were last checked, and every source it cites has its own checked date. We only change those dates when we've actually re-checked. An automated check refuses to publish a page that types a price directly instead of reading it from our price book, uses a source not checked in 120 days, or renders a broken figure.

What we can't do

No guide replaces a quote. Prices in your area, for your house, depend on things only a tradesperson can see. Use our ranges to judge whether the quotes you get are sensible, and ask about anything that falls outside them.