Schedule overrun is one of the greatest hindrances to construction project performance, thereby making schedule management an integral part of construction project management. The aim of this study is to examine how the effect of sustainable energy management (SEM) and sustainable waste management (SWM) on schedule performance (SP) is mediated by technological complexity (TC) and moderated by project size (PS). Data were obtained by means of a questionnaire survey of 168 completed construction projects in Nigeria. The partial least squares structural equation modelling (PLS-SEM) technique was adopted in analysing the collected data. The results show that TC partially mediates the relationship between SWM and SP, while TC fully mediates the relationship between SEM and SP. Also, the findings of the study indicate that the negative effect of SWM on SP will be greater with large PS. This study contributes to previous studies in the area of schedule management, by providing empirical proof to explain the means through which SWM and SEM could lead to SP through TC, and how this would vary depending on PS. The study proffers ways for contractors to improve the SP of their projects considering PS and TC.
The adoption of green construction practices (GCP) has been on the increase in recent years as a means of reducing the negative effects of construction on the natural environment. However, GCP have been discovered to expose the construction workers to numerous health and safety (HS) risks, resulting from a decline in safety investment due to the economic burden associated with its adoption. This study explores the means through which GCP influence the HS performance of construction projects through economic performance. To obtain the views of contractors, a survey questionnaire was developed, and data was collected from project managers and site managers of "class A" contractors, with a response rate of 81.55%. The partial least squares structural equation modeling (PLS-SEM) technique was adopted to analyze the data. The results show that the effect of GCP on HS performance is fully mediated by economic performance. The study concludes that for projects that adopt GCP to have high levels of HS performance, they are required to have an optimal economic performance. Efforts should be intensified by the government in providing subsidies, tax waivers, and other incentives for adopters of GCP to ensure the economic performance of their projects since it guarantees high HS performance.