No published national figure for quantity growth against the priced schedule

What it is. None - no Australia-wide source read measures the final measured quantity against the schedule quantity.

Sample. Search terms: quantity variation; quantity growth; bill of quantities variance; schedule of rates final account; remeasurable contract; earthworks quantity variance; unit rate contract quantity overrun; Auditor-General road construction contract variations; Austroads estimated against actual quantities. Eight national or state sources were opened and none reports measured against schedule quantity. Related shares that are not this cause: Grattan found scope changes explain about 11% of the cost overrun on 51 Australian transport projects over $100 million (additions to what is built, owner-side, between announcement and completion); Love and colleagues found change orders at 11% of work value for one contractor. A Queensland Transport and Main Roads variation study (USQ, Purvis 2015) was found but could not be opened (connection refused again at review, 2026-11-02). It covers Queensland Transport and Main Roads only, so it could not fill the national cell. A further search at review for an Austroads, Auditor-General or road agency quantity outturn study found none: Baccarini's contingency study of 48 road projects and a NSW road authority estimating study compare cost against estimate, not measured against schedule quantity.

What it is not. Recorded as none on purpose: no defensible Australia-wide figure for how far measured quantities exceed the schedule on re-measurable contracts was found, not that none exists. The 11% figures above are shares of a different thing and are not offered as proxies.

Where it came from

• Terrill & Danks (Grattan Institute) (2016), Cost overruns in transport infrastructure
  Section 1.3.1, Figure 1.5 (p.13) · source record

Considered and set aside

• Love, Irani, Smith, Regan & Liu: 67 projects from one contractor; change orders were 11% of work value. A change order is an instructed variation of scope, design or error, not a difference between the schedule quantity and the quantity measured, and the paper does not separate re-measure.
• Ryan & Duffield: 28 megaprojects reported by final profit against tendered profit. No quantity measure, and the paper does not split the loss by cause.
• WT Partnership, for the Independent Pricing and Regulatory Tribunal (NSW): Compares two estimates of quantities (consultant against council) for one NSW plan before construction; earthworks differed and the council's estimate was 6% high. It is a pre-construction check, one plan, one state, and the error ran the other way.
• Victorian Auditor-General's Office: Victoria only, four projects, budget overspend of 0% to 9% attributed to land prices and geotechnical conditions. No quantity data.
• Bureau of Infrastructure, Transport and Regional Economics (BITRE): National road-works cost shares and price indexes. They say what money goes on labour, materials and equipment, with no measure of quantities built against quantities priced.
• Infrastructure Australia: National pipeline and capacity analysis. Reports input price sentiment and productivity, with no project quantity outturn.
• Infrastructure Australia: Says there is no consistent project-level data on subcontracting and self-performance, and proposes a workstream to collect core measures such as budgeted against actual cost (p.61). It holds no quantity outturn, and does not itself say budget-against-actual data is absent.
• Australian Bureau of Statistics: Industry income, expense and labour totals in dollars. No physical quantities and no job-level outturn.

overrun/quantity_growth_none_au · AU · F42 ·the record ·link to this figure ·dispute this figure(or email support@demiton.io)