The true cost of construction material wastage: a case study

The true cost of construction materials wastage for a typical 8-yard mixed skip in the UK is widely quoted as £1300. This cost is at least 15 years old and needs to reflect the current practices. This study calculates a preliminary updated cost of construction materials waste whilst developing a robust methodology that can be applied in more extensive projects. Three contractors agreed on site selection, relevant risk assessments, timings, and availability of personnel based on selection criteria. The data was collected from the three sites involved - commercial, civil engineering, and residential building projects. The calculation of cost data included material costs - contractor purchase price per unit from bills/invoices; industry standard cost book (SPONS) per unit; and builders’ merchants and trade catalogues whilst the contractors provided hourly rates for labour costs. The commercial project mostly contained plasterboard, timber and demolition wastes resulting from ‘cutting waste’ and ‘stripping out’ with some of the wastes suitable for recycling. The civil engineering project mostly contained welfare waste and non-construction source with the welfare wastes recorded as ‘mostly recyclable’ (large quantity of plastic and metal drink containers). The residential project contained a wide variety of waste, including packaging, insulation, timber and plastic resulting from ‘cutting waste’, ‘unrecovered packaging’, and ‘damage’. Therefore, the new cost for an average 8-yard mixed skip is estimated as £1,619. The method developed also identifies the ‘root cause’ for each waste item in the skip, and allows targeted strategies for reduction to be implemented thereby forming the basis for further research.