A cost-plus estimating framework for BIM related design and engineering services

More than ten years have passed since Building Information Modeling (BIM) was introduced in Korea, but the industry lacks established approaches to assist firms in estimating the costs of providing additional BIM services in the design phases of a project. The deficiency also inhibits government agencies to allocate discrete and reasonable budgets when requesting BIM related services. This research focuses on the Architecture and Engineering (AE) industry and provides a framework to estimate costs for BIM design services based on the cost-plus pricing approach. The framework utilizes cost data from 54 projects to estimate average man-hours, and ‘man-hour coefficients’ for standard and non-standard work items. The man-hours can further be broken down to different design phases, disciplines and at different levels of development. The framework was implemented in an Excel-based system, which allows users to produce estimates for 11 different building project types, while providing flexibility in selecting preferred BIM services. Validation showed that the system produces accurate estimates for specific projects with customized requirements. By providing an objective approach for estimating the costs of BIM services, it allows clients and AE firms to agree upon a fair cost, and thus expedite its adoption in Korea.