Building Design Coordination: Comparing 2d and 3d Methods

Coordination of Mechanical, Electrical and Plumbing (MEP) systems among themselves and with the architectural, structural and other building systems is an important, challenging and time consuming task on the design phase of multistory buildings. Many researchers have already expressed a critical view on the most widely adopted coordination process, which makes use of transparent trade drawings overlapped on a light table for detecting conflicts. The use of a 2D CAD system is nothing but a direct replacement for paper drawings and light table, not considerably changing the method. The authors of this paper, like others, advocate the use of 3D CAD for the coordination process as a more apt tool for this spatial task. Two studies were conducted to compare the performance of a 2D CAD-based coordination method to that of a 3D CAD supported process, both in terms of efficiency and efficacy. Both methods used 2D CAD drawings as input but the three dimensional process required subsequent solid modeling of all relevant building systems. Even with this additional burden, the 3D-based method outperformed the traditional one. Results show its higher efficiency as there was a significant decrease in the time spent for detecting interferences during the development of a masonry production design in an experimental study. The higher number of conflicts revealed in the plumbing design for a multistory building demonstrated also its increased efficacy in a case study.