Analysis of Cost and Quality Relationship of Private Building Projects in Abuja.

Abstract

Time, cost and quality targets have been identified as the main criteria for measuring the overall success of construction projects. However, previous research shows that little evidence exists of successful projects where these factors are balanced. The aim of this research is to study the cost and quality relationship of private building projects executed in Abuja, thereby achieving a result that will show whether time and quality are effectively related to cost of construction or not. To achieve this aim the following objectives were examined: to determine the relationship between time and cost of selected private building projects in Abuja; to determine the relationship between quality and cost of selected private building projects in Abuja. The objectives of this research were achieved by obtaining time-cost relationship data for 30 completed private projects in Abuja. The data were obtained from consultant Quantity Surveyors who handled the projects. Cost-quality data were obtained through administered questionnaire to owners of the selected private buildings under consideration. 30 questionnaires were distributed, received and used for the analysis. The relationship between time and cost was analyzed by calculating the required effective duration for each project using time-cost relationship model developed by Ogunsemi and Jagboro (2006) which is given as T= 168.895 + 0.491C (if C ≤ 557) or 709.66 + 0.884C (if C ˃ 557). Where: T= effective project duration in relation to a given cost from date of site possession to practical completion (in working days). C= cost of the project (in millions of Naira). The calculated effective duration is compared with the actual duration, and the difference between the two defines the nature of time-cost relationship on percentage basis. The relationship between quality and cost was analyzed by finding the average percentage of quality obtained as provided by building owners in the questionnaire and comparing same with percentage quality expected (100%). The difference between these two defines the nature of cost-quality relationship in percentage. It was discovered that at a given cost, private building projects in Abuja are executed within duration that is 54% earlier than the required time but at a quality that is 10% lower than expected. In other words, the execution of private building projects in Abuja takes only 46% of the required time whereas only 90% of the expected quality is achieved. Based on the result of this research, it was therefore recommended that since the time-cost relationship is highly effective, this should be continuously maintained. As a result of loss of quality observed by this research, it was also recommended that additional attention should be given to cost-quality relationship in executing private building projects in Abuja so as to eliminate the laps. The study contributes to the body of knowledge by making the contractor/consultants know how to achieve maximum quality at an affordable cost, thereby ensuring high level of safety performance.