Synthetic worked example
Synthetic worked example: pricing a four-item BOQ
An invented BOQ with explicit quantities, illustrative rates, allowances and checked arithmetic. No customer project or CAIS performance claim.
SYNTHETIC WORKED EXAMPLE. Every quantity, rate, date and project assumption is invented for teaching. This is not a customer case, market quotation, CAIS fee or measured CAIS output.
Scenario and assumptions
Imagine an entirely invented small work package called Practice Package A. The assumed pricing date is 1 October 2026. All monetary values use illustrative currency units with no connection to a national currency or current market. The table describes scope for arithmetic practice only.
Assume the four unit rates cover their stated measured work. Add a separate 5% concrete quantity allowance, an 8% overhead allowance on direct cost including that concrete allowance, and a 10% contingency on the resulting base estimate. These percentages are choices for this example, not recommended industry allowances.
- Tax, escalation, profit, design fees and works outside the four rows are excluded.
- The concrete allowance applies only to concrete; no other quantity allowance is assumed.
- No drawing was measured and no CAIS service was executed to obtain these values.
Input quantities and invented rates
Multiply each quantity by its invented unit rate. Unit rates are expressed per the unit shown. All amounts are illustrative currency units.
| Item | Unit | Quantity | Unit rate | Amount |
|---|---|---|---|---|
| Concrete | m³ | 12.00 | 250.00 | 3,000.00 |
| Formwork | m² | 70.00 | 45.00 | 3,150.00 |
| Reinforcement | t | 1.80 | 900.00 | 1,620.00 |
| Blockwork | m² | 95.00 | 38.00 | 3,610.00 |
Calculate and reconcile the total
The measured direct cost is 3,000.00 + 3,150.00 + 1,620.00 + 3,610.00 = 11,380.00. The additional concrete quantity is 12 × 5% = 0.60 m³, giving an additional 150.00. Direct cost including that allowance is 11,530.00.
Overhead is 11,530.00 × 8% = 922.40. The base estimate is therefore 12,452.40. Contingency is 12,452.40 × 10% = 1,245.24, giving a scenario total of 13,697.64. Keeping the percentage basis explicit prevents an allowance being counted twice.
| Calculation step | Amount |
|---|---|
| Measured direct cost | 11,380.00 |
| Concrete allowance: 5% of concrete only | 150.00 |
| Direct cost including allowance | 11,530.00 |
| Overhead: 8% of direct cost including allowance | 922.40 |
| Base estimate before contingency | 12,452.40 |
| Contingency: 10% of base estimate | 1,245.24 |
| Illustrative scenario total | 13,697.64 |
What a reviewer would challenge
Correct arithmetic does not establish that the quantities, scope or rates are suitable for a real project. A reviewer would ask where the measured quantities came from, whether each rate covers the intended work, and whether the allowance basis matches the estimating brief.
- Trace quantities to current drawings and measurement notes.
- Replace invented rates with authorised, dated pricing evidence for a real estimate.
- Explain overlaps and exclusions before comparing this package with another estimate.
- Review uncertainty separately; adding contingency does not repair an omitted work item.
Methodology and limits
The inputs were created specifically for this original editorial exercise. Line amounts and allowances are calculated directly from those inputs; there is no external rate source, customer data or performance measurement. The values demonstrate a calculation method only.
For practice, prepare an invented Excel or CSV BOQ and use the public pricing trial. Its generated result requires human review and will not necessarily match these deliberately invented rates. Experimental QTO must be independently validated before its quantities support pricing.