The failure of cost anticipation and allocation in construction is attributable to ignorance of the natureudand values of elemental direct costs in developing countries. This study aims at providing bases forudprecise and simplified prediction and management of direct costs of structural building elements forudlabour-only contracts. The objectives of the study are to identify quantitative variables influencinguddirect costs of structural building elements and develop cost prediction models for small and mediumudrise buildings. A total of 216 low and medium rise building projects were used for analyses. Data wereudobtained from cost records and published data. Tools used for data analyses were descriptive andudstandard regression analyses. The results show that the six models developed have adjusted R2udranging between 0.742 and 0.830 indicating high degree of prediction dependability. Of the elevenudvariables reliably used to predict the direct costs of six structural building elements the gross floorudarea, bid price and labour prices made the strongest unique contribution to the direct costs. It isudrecommended that direct costs should be predicted with elemental cost models adopted for simplifiedudproject planning, accurate cost prediction, and ease of overhead allocation among low and mediumudincome families who mostly use labour only contract system.
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