A project budget for supply is built up from measured area, not from a rate per square metre alone. Net floor area is taken from the schedule, then adjusted upward for cutting wastage — typically 5 to 8 percent for straight-lay engineered and vinyl, higher for pattern-lay, herringbone or diagonal installations.
The line items that populate a budget are: primary product at landed rate, adhesive or underlay, transitions and accessories, freight to site, and a programme contingency. Where the project spans multiple stages, batch reserve stock is a separate line — not part of the primary quantity.
01What moves the number
Product substitution and colour custom drive the largest variances at tender. Programme certainty drives the second largest — a rate priced against a six-month production window will not hold against a two-year staged draw. Freight moves independently of both and should be reviewed against the actual delivery basis before the budget is committed.