Understanding the Role of the Estimator
Estimating is more than “pricing a build”. It’s a structured forecasting process that blends technical knowledge, measurement accuracy, supplier relationships, and risk awareness. A good estimate isn’t just a number — it is a financial roadmap for the entire project.
Types of Estimates
Preliminary / Feasibility Estimates
Used early in a project, based on historical rates and broad assumptions. Suitable for concept plans or developer feasibility studies.
Detailed Estimates
A line-by-line breakdown of every trade, task and material. This level of detail is required for fixed-price residential contracts in Australia.
Bill of Quantities (BoQ) Based Estimates
Common in commercial work. The BoQ becomes the contract pricing schedule — contractors price the quantities provided by the QS.
The Measurement Process
Regardless of software or spreadsheet, the measurement workflow remains consistent:
- Review drawings and specifications.
- Establish assumptions (site access, soil class, finishes, services extent).
- Measure quantities by trade.
- Apply labour, material and subcontractor rates.
- Add overheads, margins, and allowances.
Key Quantities Every Estimator Must Understand
- Concrete: Volume (mÂł), mesh, bar schedules, pump time, curing requirements.
- Timber/Steel: Linear metres, sections, connections, bracing requirements.
- Cladding & Linings: m² coverage including waste factors.
- Services: Usually subcontract priced — but the estimator must validate against benchmarks.
Common Estimating Mistakes
- Forgetting site-specific costs: Rock, spoil removal, temporary fencing, erosion control.
- Failing to read engineering revisions: A single change in a footing detail can add thousands.
- Assuming rates are universal: A carpenter in inner Melbourne is not the same rate as one in regional QLD.
Expert Tip: A good estimate makes risk visible. Every “grey area” should be highlighted, clarified, or an allowance added.