Editorial and evidence policy
This policy explains how we choose sources and fix mistakes. It also says how we stay independent.
Evidence before certainty
An early suitability read can flag useful questions. However, it cannot approve a design. Our guides say so plainly. They do not claim more precision than a few property questions can give.
Source order
- MCS's own installation standard (currently MIS 3002 v6.0) and certified-installer register.
- RECC's consumer code and Competition and Markets Authority guidance on unfair commercial practices.
- Other official UK energy-policy reporting for context.
- Commercial provider material only for clearly labelled examples, never as the sole basis for a technical or pricing claim.
Where town data comes from
Each town page uses figures from named bodies. Solar output comes from PVGIS, the European Commission's free modelling tool. We use its PVGIS-SARAH3 satellite data for a south-facing roof at 35 degrees.
The grid operator for each town comes from published network area maps. The planning authority is the local council, and we link to its own planning pages. For example, a Leeds page links to Leeds City Council.
Output figures are models, not promises. Your roof, shade and weather will change the result. So we always say they are estimates.
How we check facts
We keep a register of the facts we use. Each entry records the claim, the source, the date we read it and a short quote. If a source cannot be read, we do not quote it as if we had.
Rules also change. England altered its solar planning rules in August 2026, so we point to the Planning Portal and do not repeat detailed limits. Likewise, prices come from government data, not from sales material.
AI-assisted production
Automated tools may help organise research, draft outlines and refresh figures against current sources. A page is not published just because a tool produced it.
Claims must fit the cited sources, because a tool can be wrong. We avoid duplicate pages. Page metadata must describe the visible content accurately.
Review and corrections
Every guide carries a review date. A changed date should reflect a real review or a material edit. We check standards references against MCS data at each review.
We make corrections in place, so the page always shows the latest fix. Report a problem through the complaints and corrections page or the contact page.
Commercial separation
Page order follows user need, not the commission value of an enquiry. Any active referral relationship or paid placement must be labelled. An installer cannot buy an unqualified endorsement.