Calculator audit
Grey structure methodology
Reproduce every base rate, city factor, storey adjustment, area conversion and material ratio used by the main calculator.
Audit the calculatorEvidence-based library
Measure the right area, audit quantities, compare scopes and update rates without turning a planning estimate into false precision.
Start with the decision in front of you. If the area is uncertain, read the area guide before using a rate. If a quotation is difficult to compare, normalize scope before comparing totals. If work is about to be covered, use the site checklist while evidence is still visible.
Each guide separates four layers that are often mixed together: a mathematical conversion, a site measurement, a project specification and a market rate. Primary sources establish the regulatory or technical context. Worked examples show the arithmetic. Local assumptions are labelled rather than presented as national facts.
Calculator audit
Reproduce every base rate, city factor, storey adjustment, area conversion and material ratio used by the main calculator.
Audit the calculatorArea measurement
Build a floor-by-floor area schedule and avoid mixing land units, footprint, coverage and total constructed area.
Measure area correctlyConcrete
Convert drawings into a shape-by-shape volume take-off and understand why nominal ratios are not mix designs.
Estimate concrete quantitiesReinforcement
Turn bar marks, diameters, cut lengths and counts into a traceable mass schedule before waste.
Build a steel take-offMasonry
Measure walls by thickness, deduct openings and reconcile nominal brick modules with actual units.
Build a masonry take-offProcurement
Normalize area, scope, specification, commercial terms and provisional items before ranking prices.
Compare quotations fairlyCost control
Use dated supplier evidence and PBS price direction without treating a national series as a local quotation.
Refresh planning ratesSite records
Record approvals, dimensions, reinforcement, concrete, masonry and concealed-work evidence at the right stage.
Open the site checklist
Sources establish the technical context. Calculator planning assumptions remain separately labelled and should be checked for the specific project.