Comparative accuracy of floor area, storey enclosure and cubic methods in preparing preliminary estimate in Nigeria
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Date
2011
Authors
Akinsiku, O. E.
Babatunde, S.O.
Opawole, A.
Journal Title
Journal ISSN
Volume Title
Publisher
Macmillan Publishers Ltd.
Abstract
The aim of construction cost forecasting is to provide an estimate of a construction contract. Construction clients are interested in knowing their financial commitment before the completion of a detailed design. There are various methods used by estimators to forecast the construction cost of building and civil engineering projects. The accuracy of these techniques is, however, impeded by some external factors that need to be overcome or are provided for in order to get a realistic estimated value. This study examined the three most common techniques used in preparing preliminary estimates in Nigeria, namely, the floor area or superficial method, the cubic method and the storey enclosure
method. Total construction costs were extracted from the final accounts of 10 bank projects executed within the last 15 months in Lagos metropolis, Nigeria. From the extracted costs, using a random selection, a project was used as the base on which other techniques were used. The data were analysed using their respective deviation from the final cost and the Pearson correlation coefficient was used to test their degree of relationship with the final cost. The study revealed the cubic method of calculating preliminary estimates as having the highest frequency of accuracy closest to the obtained construction value with respect to the 10 projects sampled, whereas the floor area and storey enclosure methods followed behind. However, using the Pearson product moment correlation coefficient, the floor area or superficial method has the greatest relationship to the construction cost; the cubic method came second, whereas the storey enclosure method has the least relationship with the construction cost.
Description
Staff publications
Keywords
Accuracy , Preliminary estates , Construction cost , Building , Research Subject Categories::FORESTRY, AGRICULTURAL SCIENCES and LANDSCAPE PLANNING
Citation
Akinsiku, O. E., Babatunde, S.O., & Opawole, A. (2011). Comparative accuracy of floor area, storey enclosure and cubic methods in preparing preliminary estimates. Journal of Building Appraisal. 6, 315 – 322.