Costing is the process of applying appropriate costs or rates to the line items in an estimate or bill after the quantities have been taken off.
Once the quantities have been measured, the estimator or QS prices each item, either by building up a rate from labour, plant and materials, by using rates from previous projects or price books, or by obtaining quotations from subcontractors and suppliers. The priced items are then totalled, and additions are made for preliminaries, overheads and profit, and risk. The accuracy of costing depends on using rates that reflect the specification, location, quantity and timing of the work.
- Rates should be adjusted to the base date of the estimate.
- Check what each rate includes, such as waste, fixings or attendance.
Related terms: take off, rate build up, pricing, estimating.
