ABSTRACT
Contingency funds are included in project estimates to manage risk and uncertainties associated with a construction project. The fund is calculated in various ways. In most cases it is either underestimated or inflated. The aim of this research work was to evaluate the contribution of Cost Contingency toward successful execution of building projects in Nigeria. To achieve this aim the impact of contingency provision in some selected building projects had been evaluated. Data for this study was obtained from 40 project files of completed buildings obtained from 10 organizations.. Furthermore 100 comprehensive survey questionnaires on project Cost Contingencies were randomly distributed to Quantity Surveyors and Project Managers with 67% response obtained. The data were analyzed with the aid of simple statistical tools using SPSS package. The study found that although the inclusion of contingency allowance reduces the incidence of project cost overrun, 55% of the projects considered were in excess. It was also found that projects exceed their initial cost estimate by an average value of 5.07% where contingency is applied and by an average value of 9.52% where no contingency is applied. Based on the results it was concluded that, there is a lack of application of quantitative risks analysis in the determination of contingency fund. Therefore to improve the accuracy of Cost Contingency allowance an application of quantitative risk analysis techniques in its estimation has been recommended.