Despite many efforts from software vendors, AEC community and researchers, interoperability is still one of the main issues regarding reliable and robust transfer of information among different applications. In most cases, the Industry Foundation Classes (IFC) files fail to provide proper interoperability between geometric building models (architects) and thermal simulation software (engineers). This causes time consuming interactions and manual corrections prompt to errors. This paper evaluated two approaches for an efficient and robust transfer of IFC models considering space boundary characteristics to conduct thermal energy simulation (TES). The first approach was a multi-platform process which IFC files could be used by different TES tools. The second consisted of a single-platform process in which a single CAD software with built-in energy simulation capabilities was used. The two processes were tested with a simple residential building. Results indicated that the first process still required manual corrections and its performance was influenced by the TES tool used. The second approach addressed the interoperability problems, but caused "software dependency". It was found that geometry data reflecting different levels of space boundaries significantly influenced energy simulation results, indicating that proper definition of space boundaries improved the robustness of IFC files. This showed that IFC files can be enhanced to facilitate TES. This study also showed opportunities for improvement regarding interoperability and suggested other ways to tackle this problem.