Intelligent BIM-Based Drafting & Design For Manufacturing

Building information modelling (BIM) is an emerging technology in the AEC industry that has seen increased adoption in recent years. Although it is intended to address a wide range of challenges encountered in the AEC industry, BIM can be expanded to fulfil the needs of construction practitioners in terms of designing and drafting, especially for framing and boarding of light-frame residential buildings. Traditionally, framing and boarding activities on site require construction framers to use their practical knowledge and understanding of the overall manufacturing process. Moreover, the design and drafting requirements associated with modular construction exceed those of the traditional stick-built method.

This research focuses on the development of a framing add-on (called “FrameX” ) to Autodesk Revit, which is a popular CAD software in the North American construction industry. The developed add-on can automate the design and drafting of framing and boarding elements, including generation of detailed shop drawings, bills of materials, and cutting layouts for light-frame buildings. The use of this add-on saves a significant amount of drafting time and reduces human error, resulting in an increase in overall accuracy and efficiency of the design and drafting process.

Autodesk application programming interfaces (APIs) and software development kits (SDKs) are used to extend the capabilities of Revit using programming languages such as C#. The research team automated existing features with Autodesk Revit and also added features such as this framing add-on.

The degree of effectiveness of BIM models in communicating information among project stakeholders plays an important role in determining the construction efficiency. To make a BIM model fit for use by contractors and sub-contractors, it needs to be furnished with sufficient construction detail (i.e., construction-specific information) for specific application needs. Such detailed BIM models are vital in project coordination and decision making in relation to construction material take-off and usage at the construction stage. Nevertheless, developing a construction-centric BIM model through manual modelling is time-consuming and error-prone. Furthermore, trades know-how in the construction industry remains mainly in the minds of experienced trades people and is generally missing from existing design software or is otherwise inaccessible to building designers. As such, construction-centric designs generated by building designers using existing BIM design software usually fall short of practical constructability analysis, resulting in considerable material waste and re-work in the field. This study thus explores a BIM-based automated approach to boarding design (i.e., optimizing and modelling sheathing and drywall layout design) in the light-frame building industry. This approach advances the current practice in the field by adapting BIM design models for construction practitioners in an automated fashion.

This research develops an automated drafting and planning system for window manufacturing. As an engineering-to-order component, a window requires customized design. In current practice, window manufacturers usually obtain the building information based on 2D drawings from the customer. Sales personnel will input the specifications to generate a quote and 2D drawings for windows. The information then flows to the Enterprise Resource Planning (ERP) system to generate customer orders for the scheduling and manufacturing department. There are several identifiable issues with the existing practice: (1) lack of details for 2D drawings of windows; (2) time-consuming manual process for scheduling customer orders; (3) information often missing from the “work traveller” (a sticker that specifies all the window components and hardware information); (4) work traveller lacks detailed data for specific workstations; and (5) the process is highly reliant upon the worker’s experience. 

The proposed method addresses the above issues by implementing manufacturing-centric BIM. A higher-level-detailed design can be developed to improve the design efficiency and accuracy, and specific information for each station can be generated to achieve workstation-based information delivery through the computer, reduce process waste, and reduce human error. In this manner, automation in drafting and planning for window manufacturing under BIM environment can be achieved in order to provide a design and assembly plan complete with a BOM for the window structure as well as manufacturing information for each workstation.

With the emergence of BIM, off-site construction is gaining momentum in the construction industry. This construction method can benefit the industry through improved productivity and reduced waste. However, it also poses new challenges to building designers and construction practitioners with respect to building design and construction planning. For example, when designing building products and BIM models, designers need to consider manufacturing process constraints in order to harness the benefits of manufacturing technology. This is in part due to the fact that, in the off-site construction paradigm, building design must be transformed from product-focused to manufacturing process-driven. In current practice, considerable human involvement and off-site construction knowledge are required in order to adapt the building design (e.g., panelized building objects) to the manufacturing context within the BIM environment.

In this regard, the key contribution of this research is the development of a BIM-based algorithm for panelizing building components. For example, the proposed algorithm is capable of determining the granularity of wall panels and optimizing the configuration of multi-wall panels under engineering constraints, thereby improving productivity. The proposed approach is implemented within an Autodesk Revit environment using API. A case study of a residential building is used to demonstrate the proposed approach.

Off-site construction and building information modelling technology brings benefits to the construction industry in many respects, such as reduced material waste, and leads to solutions that are moving the construction industry toward a more sustainable approach. Nevertheless, despite the uptake of off-site construction methods and BIM, a considerable amount of construction waste in the form of sheathing material (e.g., oriented strand board) is still generated in the light-frame building industry. This research thus presents an automated BIM approach to reducing sheathing material waste by enabling proactive designs and the planning of roof sheathing installation for modular buildings. Specifically, a BIM-based sheathing layout design algorithm, which incorporates trades know-how, is developed in order to achieve construction design automation. A hybrid algorithm integrating greedy algorithm and particle swarm algorithm is applied in connection with the design algorithm to optimize material cutting plans for the generated layout with the objective of minimizing sheathing material waste. Two case studies are presented to demonstrate the feasibility and effectiveness of the proposed approach in terms of roof sheathing material waste reduction. The results are summarized to provide deeper insights into sheathing waste reduction for more sustainable construction practice.

As the construction industry shifts towards automation and industrialized construction, and given that, in this context, construction processes are completed by automated machines in a production line setting, it is possible to estimate the production time and the associated cost with a higher level of accuracy. Additionally, with the rise of BIM applications in industrialized construction, a significant benefit is gained in terms of the data transformation between the phases of the projects. 

In the present research, a framework for a BIM-based estimation system is developed to generate accurate and detailed production estimates based on the machine’s motion and the geometric information of the project, where the motion of the moving parts of the machines’ structures are investigated in order to calculate the speed and distance each part travels in a given cycle. The developed estimation system is also used for maintenance scheduling purposes to calculate the life cycle usage of each part in the machine.