Unit rate estimating.
Unit rate estimating is the most common method for pricing construction work. Each item of work is given a rate per measurable unit — per square metre of brickwork, per cubic metre of concrete, per linear metre of drainage.
Who this guide is for
Estimators, quantity surveyors, and contractors who need to build rates from first principles or adjust standard rates for specific projects.
Building a unit rate
A unit rate has three components: labour, materials, and plant. Labour is calculated from gang composition and productivity. Materials include the base cost plus waste. Plant includes hire, fuel, and operator costs. Overheads are sometimes added as a percentage uplift rather than included in individual rates.
Miniature example
Concrete in foundations (per m³):
Materials: C25 concrete £115/m³ + 5% waste = £120.75
Labour: 2 labourers × £20/hr, 0.5 hrs/m³ = £20.00
Plant: poker vibrator £8/hr × 0.25 hrs = £2.00
Total unit rate: £142.75 per m³
Common mistakes
- Using composite rates for non-standard work without adjustment
- Double-counting overheads in unit rates and in a separate preliminaries section
- Not updating material or labour elements when costs change mid-project
Related guides and tools
Learn about building up labour rates and material pricing. Try the Construction Estimator to apply your own unit rates.