Currently in the AEC market of China, most of the design projects are documented in the form of 2D-drawings, which impedes the paradigm shift towards BIM-based construction. This project aims at developing an automatic building information model generation software based on CAD drawings. Such tool will help with the BIM-BEM model transformation process to faciliate the HVAC system design automation. Recognition algorithms of both graphic and semantic objects will be established, coupled with domestic Revit component-family database to create a simpler BIM tailored for the BEM workflow.