AN EVALUATION OF THE EFFECTS OF NON-PHYSICAL WASTES ON BUILDING PROJECTS PERFORMANCE

Abstract

Non-physical waste (NPW) is one of the challenges that is engendering low performance levels, yet an underexplored contributor to poor performance in the construction sector, particularly in developing countries, where emphasis has mainly been on material waste. Previous studies have identified NPW, limited attention has been given to how different NPW types separately influence multiple project performance measures (PM). This paper, therefore, aims to evaluate their distinct effect on six (6) PM, such as quality, cost, time, safety, satisfaction, and productivity. An extensive literature review was done to identify the NPW types and PM. A questionnaire survey method was administered to construction professionals in Abuja, Nigeria, through a purposive sampling technique. A reliability test was conducted to check the suitability of the data and the data were analysed using descriptive statistics. The study revealed that the data have good reliability with Cronbach's alpha of 0.96. More importantly, the results show that NPWs create performance-specific impacts: ‘waiting’ had the greatest impact on time performance (3.81); unused talent’ (3.61) has the most impact on quality performance; 'defect/rework' has the greatest impact on cost (3.79) and productivity performance (3.75); and accidents related waste critically impact safety (3.47) and client satisfaction (3.54) categories. In conclusion, NPWs should not be seen as a single unit but as distinct performance-related risk factors requiring targeted management strategies. Thus, enhancing awareness, stronger supervision, improved workforce structure, and structured communication systems are recommended to minimise the high impact of NPW.