Project cost estimating is an important part of construction project management. Traditionally, estimators use project drawings and specifications to create quantity takeoffs (QTO) and subsequently calculate sub/total costs based on their judgments and historical cost information.During the past decade, BIM practitioners in academia and industry have aimed to leverage BIM capabilities for cost estimating to overcome the current challenges. The result is BIM-enabled methods for QTO and cost estimation also known as Model-Based Estimating (MBEst). However, the effectiveness of MBEst has been limited mainly due to a lack of standard MBEst workflows and a lack of integration between design development and cost estimating processes. In response, the intent of this technical report is to make a comprehensive review of model-based QTO/estimating and to provide a standard method for BIM experts to adopt and implement MBEst.
This report is a product of a study led by Prof. Carrie Sturts Dossick, Director of the Center for Education and Research in Construction (CERC) and Faculty lead in the Communication Technology and Organizational Practices Research Group (CTOP) at the University of Washington and Assistant Professor Hyun Woo Lee in the Department of Construction Management. The research team included Alireza Borhani (Research Analyst, University of Washington), and Dr. Laura Osburn (CERC Research Scientist, University of Washington).