Many modern commercial buildings involve complex shaped façades, resulting in increasing complexity as well as challenges in façade fabrication and assembly processes. Currently, fabrication drawings are essential for fabrication, design evaluation and inspection of building components. Computer-aided automation, which can significantly improve the efficiency and accuracy of the fabrication and assembly process, is thus essential for the generation of façade fabrication drawings, thereby supporting the fabrication and assembly of the building façade components. Among current computer-aided technologies, building information modeling (BIM) has been widely applied to many sophisticated building projects due to its comprehensive ability in digital representation of building mode...[ Read more ]

Many modern commercial buildings involve complex shaped façades, resulting in increasing complexity as well as challenges in façade fabrication and assembly processes. Currently, fabrication drawings are essential for fabrication, design evaluation and inspection of building components. Computer-aided automation, which can significantly improve the efficiency and accuracy of the fabrication and assembly process, is thus essential for the generation of façade fabrication drawings, thereby supporting the fabrication and assembly of the building façade components. Among current computer-aided technologies, building information modeling (BIM) has been widely applied to many sophisticated building projects due to its comprehensive ability in digital representation of building models. BIM has demonstrated its advantages over generating different types of drawings. However, generating fabrication drawings for façade panels using conventional approaches is time-consuming and error prone, especially when the number of façade components become huge. Therefore, this thesis aims to develop BIM-based methodologies to automate the generation of fabrication drawings for façade components, thereby facilitating the whole construction process.

For façade panels, a BIM-based framework is proposed for the automatic generation of fabrication drawings for façade panels. The framework integrates both graphical and non-graphical information from BIM models and other external data sources. Specific algorithms are applied to automatically generate the graphical information on the drawing templates based on the BIM geometric models. Title blocks of the drawing templates are also automatically filled in with corresponding non-graphical information. Complete fabrication drawings as well as a tabulated file with essential graphical information on similar components are then generated automatically.

For structural components such as mullions and transoms, it is important to represent their physical characteristics clearly, thus a large number of section views need to be produced, which is a time-consuming process and very labor intensive. Therefore, automatic generation of fabrication drawings for building façade components (such as mullions and transoms) is of paramount importance. In this thesis, attempts have been made to develop an efficient framework in order to automatically generate fabrication drawings for building façade structural components, including mullions and transoms. To represent the complex physical characteristics (such as holes and notches) on mullions and transoms using minimum number of drawing views, a computational algorithm based on graph theory is developed to eliminate duplicated section views. Another methodology regarding the generation of breaks for front views is also proposed to further improve the quality of drawing layouts. The obtained drawing views are then automatically arranged using a developed approach. In addition, primary dimensions of the drawing views focusing on the physical features are also generated. Furthermore, in order to maintain the consistency of the drawing formats, a methodology is proposed to simulate the scales of the drawings by using clustering technique.

With the adoption of the proposed BIM-based methodologies, time and human effort in the generation of fabrication drawings for façade components can be significantly reduced, and all the fabrication drawings for similar components will follow a consistent drawing format with explicit layout, thereby enhancing their readability.