Paper Title
Investigating Extent And Events Leading To Cost And Time Overruns Of Public Building Projects

Abstract
Extant literature reveals abundance of studies to establish causes of overruns using a questionnaire approach. This approach has been observed to be fraught with limitations. The authors contend that the circle of investigation into identifying the causes of cost and time overruns can only be complete when the views of practitioners are complemented with investigations into the extent and events that trigger the overruns. This research assesses the antecedents of 321 completed school projects to understand the root causes of overruns. In all, 72% and 87% of the projects evaluated overran their initial budget and duration respectively. The mean cost and time overrun is also 9.6% and 106% respectively. It has been observed that any attempt to reduce the effect of change orders on only external works by 75% through proper pre-contract planning would reduce the change orders by 56%. The deduction from the investigations conducted revealed endogenous factors within the public sector system - poor project planning, payment delays, lack of enforcement of contract provisions and political interference. Similarly, excessive payment of price fluctuations resulting from project delays and uncertainties in material and labour prices, and variations are responsible for cost overruns. The findings of the research therefore present a unique opportunity in understanding the fundamental causes of overruns within public sector building projects. Knowledge of the extent of overruns is also expected to prompt policy makers and project managers on the pervasiveness of overruns. Keywords- Cost Overrun; Payment Delays; School Projects; Time Overrun;