Automated generation of shop drawings in residential construction

• Parametric modeling to build framing expert system for residential construction.
• Illustration of logical rules linking framing elements in the context of parametric modeling.
• Use of BIM philosophy to maintain information consistency among all framing elements.
• Case study demonstrating applications of the underlying parametric modeling.

The residential construction industry relies mainly on elementary two-dimensional (2D) design and shop drawings. Building Information Modeling (BIM) and parametric design have proven to be an effective technology for integrating design and construction while maintaining low cost and producing more benefits to owners, designers, and builders. However, architects, engineers, and designers may lack the time and resources needed to generate accurate BIM models or to be able to use the model information to benefit the construction process. In this paper, we propose a methodology for the automation of shop drawings for the wood-framing design of residential facilities based on a parametric model that is incorporated into a 3D-CAD model. The proposed methodology is tested in a number of virtual scenarios within the CAD environment, and is implemented as a computer program referred to in this paper as FRAMEX, a tool developed using Visual Basic for Applications (VBA) as an add-on to AutoCAD. FRAMEX adopts the guidelines at the foundation of BIM technology to generate shop drawings in which the information is consistent at every level of detail, from the studs to the panels to the home where all the panels are joined to form a single entity. It also reduces the time required for drafting design by automating the process based on 3D-CAD and parametric modeling.