Integrated Data Model and Mapping for Interoperable Information Exchange Between BIM and Energy Simulation Tools

Energy efficiency is an important aspect in building design nowadays. During the design phase, energy simulation and analysis can enhance the overall building energy efficiency at a lower cost and less delay to the project schedule. Currently, energy analysis is performed digitally in energy simulation software applications which require users to draw a virtual model and define the parameters in the application platform before running the simulations. As building information modeling (BIM) technology becomes increasingly adopted in the architecture, engineering and construction/facility management (AEC/FM) industry, BIM models are often used in construction projects. However, these BIM models are not compatible with the existing energy simulation applications, and the required model conversion often results in information loss and distortion. One reason is that the current BIM data schemas, such as the Industry Foundation Classes (IFC), do not fully support data for energy simulation and analysis. This paper presents a data model to extend BIM schemas for supporting energy simulation and analysis. The data model was developed by studying the four most widely used energy simulation software, namely eQUEST and EnergyPlus. The proposed data model was then used to extend the latest IFC4 schema. Based on the results, a mapping between the extended IFC4 schema and gbXML was also developed to allow information exchange between BIM and energy simulation software. An example scenario is presented to illustrate the potential of the extended IFC4 schema for supporting energy analysis directly.