Abstract:
Quantity calculation is a key component of the cost estimation process. Cost consultancy firms encounter various challenges such as higher time consumption, lower accuracy, higher expenditure for employees, and higher stress levels for estimators when conventional methods are practiced for quantity calculation. The drawbacks of quantity calculation with conventional methods can be effectively addressed through the adoption of 5D-Building Information Modelling (BIM) based quantity calculation. 5D-BIM is one of the dimensions of BIM which is beneficial in Quantity Surveying related aspects. Thus, this study aims to investigate the advancements of 5D-BIM that can be brought to the quantification approaches in the Sri Lankan context. Accordingly, a qualitatively based extensive literature synthesis has been conducted to review the concept of 5D BIM, ascertain the problems of conventional quantification methods, identify the key features of 5D BIM-based quantity calculation, and explore how the problems of conventional quantification approaches can be solved by the key features of 5D-Building Information Modelling (BIM) based quantity calculation. Following the qualitative approach, data were collected through eleven semi-structured expert interviews. Experts were selected through purposive sampling followed by snowball sampling. The data analysis was conducted through manual content analysis. Findings revealed context, features of 5D-BIM-based quantity calculation which solve the problems of conventional methods in the Sri Lankan context which includes high time consuming, lesser accuracy, minimal collaboration, inefficient for preliminary stage estimating and inefficient for cost planning with cross-reference to the findings in the literature review. In addition to the findings in the literature review respondents were suggested problems in conventional methods in Sri Lanka and how those problems can be addressed through key features of the 5D-BIM approach.
