Construction Cost Models for Highrise Office Buildings in Nigeria

Abstract

Existing cost estimating models offer frameworks for forecasting the probable cost of proposed construction projects. Nevertheless, they have been criticised to be either low in accuracy or slow in application. This paper describes the development of alternative costpredicting models which will be relatively faster and more accurate. Adopting the principle of cost-significant items, 15 priced bills of quantities of high rise office building projects executed or awarded in Nigeria between 2002 and 2011 were analysed. The study found thatll (29.7%) out of 37 bill items were cost-significant accounting for 72.2% of total value of the work. The implication of the finding is that by concentrating efforts on these few items will not only reduce the stress on estimators but also enhance the accuracy of cost estimates. The resulting 11 cost-significant items were used to develop Pareto-based and multilinear regression models capable of predicting construction cost to an accuracy of 5%. [ABSTR)