01
Calculation first
Calculation logic is separated from page presentation and checked against worked examples, boundary cases, and unit conversions. Formulas and material assumptions appear alongside the result.
02
Source discipline
We do not invent building codes, product claims, prices, statistics, or manufacturer requirements. Product-specific decisions should be checked against the current label, data sheet, supplier information, and local requirements.
03
Corrections
Substantive corrections should be made promptly and propagated through shared calculation logic. Readers can report an issue through the contact page.