Where our numbers come from

UK tradespeople can submit their typical prices for specific job types in their region. We verify their business credentials before any data goes live - Companies House registration for limited companies, or sole trader details for individuals. Trade-specific accreditations (Gas Safe, FENSA, NICEIC, etc.) are checked where applicable.

We publish each contributor's business name in the Trusted Contributors section on relevant pages, along with the date their data was last updated. Contributor data is anonymised before being included in regional averages - we don't show individual quotes as a public price list.

We ask contributors to update their prices at least once a year. Stale submissions (over 18 months old) are flagged and removed from the averages until updated.

Where contractor submissions are limited - particularly in the early stages of the site - we supplement with research from industry bodies, trade association published rate cards, and government data where available. We clearly label which data is research-based vs. contributor-sourced.

Sources we reference include the Office for National Statistics construction output data, the Federation of Master Builders' State of Trade Survey, BCIS (Building Cost Information Service) published benchmarks, and manufacturer-published installation cost guidance from boiler and window manufacturers.

For each job type and region, we take the middle 80% of submitted prices (removing the lowest 10% and highest 10% to exclude outliers), then calculate the median and interquartile range. The "typical price" shown on cost pages is the median; the price range reflects roughly the 25th to 75th percentile.

Regional multipliers for the London premium and lower-cost regions are calibrated against ONS construction output data and cross-checked against our own submissions where volume permits.

Each cost page shows a "Last updated" date. We review core prices at minimum quarterly, and update following significant market events - energy price changes affecting boiler demand, material cost spikes (timber, steel), or major changes in labour costs.

All pages are reviewed annually as standard. Pages flagged by readers as inaccurate get priority review within 5 working days.