Hong Xian Li

An Automatic Scheduling Approach: Building Information Modeling-Based On- site Scheduling for Panelized Construction

Panelized/modular construction is increasingly adopted within the industry as a primary construction method, with in-plant fabrication and on-site assembly as two of the main processes. Each of these two processes involves a different emphasis regarding productivity improvement: for in-plant fabrication, manufacturing process management is the main focus, while, for on-site assembly, scheduling and management of assembly operations are of particular interest. This paper proposes a generic approach by which to generate the on-site schedule automatically based on a building information model (BIM), considering the structural supporting and topological relationships among building elements, as well as knowledge of steel panel construction. The BIM model is developed in an Autodesk Revit environment, based on which precedence relationships of elements are derived automatically, and is utilized to perform the on-site schedule through the Autodesk Revit Application Programming Interface (API). The generated schedule results are exported into Microsoft Project for further analysis, such as resource leveling. A case example is provided to demonstrate and validate the methodology. This paper explores the implementation of BIM, with the scheduling of panelized construction as the focus. This research lays the foundation for further implementation of BIM using Autodesk Revit.

Carbon Footprint of Panelized Construction: An Empirical and Comparative Study

Compared with the conventional stick-built construction method, panelized construction offers greater sustainability in terms of energy, waste, and emissions reduction. The empirical research presented in this paper addresses the carbon footprint of panelized construction by quantifying and comparing the carbon emissions during the framing stage between panelized and conventional stick-built construction methods. The data for quantifying the emissions of panelized construction is collected from a prefabrication plant, Landmark Building Solutions (LBS), while the data for conventional construction is drawn from previous research of one of the co-authors. The framing phase of panelized construction, including panel fabrication in the plant, panel transportation to the site, and panel erection on site, is investigated and compared with the stick-built method. The associated emission comparison includes (1) operational emissions and (2) embodied emissions; the former has to do with direct emissions during fabrication and construction, and the latter is related to resources during the process, measured in terms of embodied emissions (cradle-to-gate). Different research methods, such as reviews of accounting records and discussion with experts in a task-group setting, are customized to different elements. The research results indicate that carbon emissions are reduced significantly through the use of a panelized construction method, compared to the conventional stick-built method.