Editorial & calculation policy
How we distinguish evidence, assumptions and useful examples.
How this content is produced
These guides and calculators were developed with AI assistance. Formula tests and checks against the linked sources form part of the publishing process. They have not received an independent professional accreditation, and no invented expert profiles or testimonials are used. Supplier examples are observations from the cited pages, not evidence of completed projects or a representative pricing survey.
Sources and factual claims
Important rules and factual claims should point to a primary source wherever possible. Records store the publisher, URL, source date when available, date checked, confidence and review status. A source supporting a general principle does not validate an unrelated example price.
Illustrative pricing
We do not currently have a representative survey of UK trade prices. Calculator defaults are deliberately labelled as illustrations and can be edited. We do not describe these defaults as national averages, local prices or current supplier offers. Obtain written quotations for an actual project.
Review and publishing
Content moves through draft, review and published states. The publishing gate requires reviewed content and useful sections. Sensitive tax content requires verified sources and a future review date; overdue sensitive pages are excluded from public queries. Automated tools prepare audit findings and briefs, and never publish on their own.
Corrections and independence
Commercial arrangements must be disclosed next to the relevant placement. A sponsored item must not be presented as an independent recommendation. Use the contact page to report a formula, source or content issue when a publisher contact is available.