Editorial & Methodology Policy

Last updated: 26 June 2026

BuildMetricLab exists to give Australian homeowners, owner-builders, and trade professionals accurate, no-nonsense quantity and cost estimates for common construction tasks.

Principles

1. Show your working. Every calculator shows the exact formula used. If you don't agree with the method, you can reproduce the calculation yourself.
2. Cite the source. Where a calculator depends on industry benchmarks (e.g., bricks per m², density, NCC Section J / NatHERS references, AS/NZS standards) the reference is listed under Sources & Methodology.
3. Estimates, not promises. We include standard wastage percentages and mark clearly where site conditions invalidate a number. We do not claim exactness the numbers cannot deliver.
4. No sponsored output. Affiliate partners have zero influence on calculator formulas or defaults.
5. Versioned math. When we update a formula, the tool's last_updated date changes and the change is recorded in the site changelog.

How we source prices

Default unit prices reflect typical Australian builders' merchant and hardware trade prices in 2026, exclusive of GST unless noted. Prices are editable in every calculator so you can plug in your own quote.

Contributor sign-off

All calculators are reviewed before publication for:

• Formula correctness against a reference textbook or Australian Standard.
• Unit consistency (metric throughout).
• Disclaimer completeness for the tool's risk class.
• Australian English spelling and terminology.

Corrections

Email [email protected] or use the feedback button on any tool page. We aim to respond within five working days.