We prefer sources that are closest to the original fact. Depending on the topic, these may include:
- manufacturer technical sheets, care instructions, safety data sheets, and written warranty terms;
- government agencies and local authorities;
- applicable codes, standards, and recognized industry organizations;
- qualified professionals working within the relevant field;
- original project records, measurements, and photographs when their origin can be verified.
Important factual claims should include a link or a clear reference that allows the reader to identify the source. Information that changes over time—such as product availability, prices, warranty terms, regulations, and trend data—must be checked again when an article is materially updated.
Search snippets, anonymous posts, competitor marketing pages, and AI-generated answers are not accepted as the sole evidence for a material factual claim.
We do not publish unsupported superlatives, rankings, guarantees, or numerical claims. Statements such as “best,” “lifetime,” “maintenance-free,” “always,” or “never” require precise context and reliable support. Estimates are labeled as estimates and should explain the assumptions that affect the result.