DEMITONResearch / Context statistics
Context
Figures that frame a disease rather than measure it, such as a typical planned margin. Never a headline.
Figures that frame a disease rather than measure it, such as a typical planned margin. Never a headline.
Updated 2026-09-25 · release v5 + 5 · all five diseases
Every figure
| Figure | Of | What it measures | Where | Confidence | Source |
|---|---|---|---|---|---|
| 9.89% | of contract value | Planned gross margin on Australian civil and transport work | Australia | moderate | Love, Irani, Smith, Regan & Liu (2017) |
| 1.98% | of contract value | Head office overhead as a share of the contract | Australia | low | O'Leary & Vaz-Serra (2025) |
The evidence
9.89%of contract valuePlanned gross margin on Australian civil and transport workAustraliaModerate confidenceContext
What it is. Mean margin excluding overheads, of contract value.
Range 6% to 9.89% (across studies)
Sample. 67 projects from one Australian contractor (9.89%); 8 Australian transport projects (almost 9%); six years of one contractor's ledgers (6% to 9%).
What it is not. Two of the three sources are one contractor's data each, and all three are the same research group. The docs page rounds this to 9%.
Where it came from
- Love, Irani, Smith, Regan & Liu (2017), Cost Performance of Public Infrastructure Projects: The Nemesis and Nirvana of Change-Orders · free copyaccepted manuscript, p.25 · source record
- Love & Ika (2021), The 'context' of transport project cost performance: Insights from contract award to final construction costsabstract, via IDEAS/RePEc (the full text returned 403) · source record
- Love, Ika, Ahiaga-Dagbui, Locatelli & Sing (2019), Make-or-break during production: the costs of reworkabstract (margins of 6% to 9%) · source record
1.98%of contract valueHead office overhead as a share of the contractAustraliaLow confidenceContext
What it is. 1.98% of contract value, head office overhead.
Range 0.99% to 1.98% (scenario)
Sample. 30 senior Australian estimators, mostly building work.
What it is not. Our multiplication of two figures, one of them a UK 2002 number cited second-hand. Use your own rate if you have it.
Our arithmetic. Head office is 9.9% of preliminaries (table 4); preliminaries are 10% to 20% of the contract sum (introduction, citing Chan & Pasquire 2002). 9.9% x 10% = 0.99%; 9.9% x 20% = 1.98%.
Where it came from
- O'Leary & Vaz-Serra (2025), Challenges in pricing preliminaries costs for contractors: An Australian case studytable 4; introduction · source record