A post-contract project analysis of material waste and cost overrun on construction sites in Abuja, Nigeria

Abstract

Material waste and cost overrun have been identified as common problems in the construction industry. These problems occur at both pre- and post-contract stages of a construction project. As a result of a dearth of empirical research and low level of awareness, the majority of managers of construction projects in Nigeria pay hardly any attention to material waste issues that affect cost overrun. This article examines the material waste issues that affect cost overruns at the post-contract stage of building projects. The study covers building construction projects in Abuja, Nigeria. In-depth interviews were conducted with professionals using purposive sampling technique. It is purposive, because only building professionals handling projects that are worth over eight million USD are consulted/interviewed. The professionals included 15 project managers, nine quantity surveyors, five site engineers and one senior technical officer of a waste management department/unit. The interviews were on issues relating to material waste and cost overruns at the post-contract stage of a project. The collected data were analysed manually, using the deductive approach. This involves constant comparative analysis of the data to generate common patterns on material waste and cost overrun. The research found that poor quality-of-procurement management, construction management, and site management would cause material waste, which contributes to project cost overruns. A good-quality procurement management entails procuring the appropriate materials, at the right time and in accordance with specifications. Rework, site accidents, inadequate site security/fencing, poor site organisation and discipline, construction-site disputes, lack of experience, and lack of co-ordination among the parties all contribute to material waste and cost overruns. It can be concluded that proper attention to material waste issues has the potential to minimise the rate of cost overrun at the post-contract stage of a project. It is recommended that careful attention should be paid to the issues identified in this study, as they would help reduce the rate of material waste and cost overrun for projects. Keywords: Cost overrun, construction industry, material waste, post-contract stage