# Thermal Performance Visualization Using Object-Oriented Physical and Building Information Modeling
## 1 Introduction  
A lack of information needed to visualize building energy simulation results prevents the efficient use of such results in developing schematic designs in the early design stages. [PERSON] et al. [1] pointed out that the visualization of building energy performance information at the early design stage can facilitate the energy-reduction strategies. Some of software applications including plug-in applications are available in the market to support building energy simulation-based design at the early design stage [2; 3; 4; 5; 6; 7; 8]. Most of the applications have the difficulty of seamless object mapping for information visualization between a building component and the simulation result. In order to improve information visualization, we investigated a platform for depicting building energy performance, focusing on thermal energy performance in building information modeling (BIM). To develop the platform, we first created a BIM model of Building Energy Simulation Test (BESTEST) Case 600 [9] to experiment with our method and develop a case study. Second, we created a thermal energy performanceindicator (TEPI) parameter to store thermal building energy performance results after conducting object-oriented physical modeling\(-\)based building energy performance simulation (OOPM\(-\)BEPS). Third, we designed a visibility setting in the BIM authoring tool that uses TEPI values to color\(-\)code building components. Finally, we developed the thermal energy performance visualization (TEPV) using the application programming interface (API) programming method. The TEPV enables building components in a BIM model to update TEPI values for simulated time and change the building components' colors automatically.  
The research objectives in developing this platform includes (1) providing the results of thermal energy performance through the TEPI parameter in BIM models, (2) displaying a series of thermal energy performance results as color-coding building components, and (3) enabling stakeholders in the early design stages to use the BIM tool as a common user interface when developing architectural models and thermal energy performance visualizations.  
Our study is significant in that we demonstrate a new method for associating the representation of thermal energy performance obtained from an OOPM\(-\)BEPS with color-coded building components in BIM. This approach is distinctly different from other building performance representations and other BEPS tools; our information visualization in BIM from OOPM\(-\)BEPS provides a new and sophisticated object\(-\)based performance visualization and mapping method. Consequently, the developed platform facilitates that architects become better informed based on the intuitive object\(-\)oriented building performance simulation results at the early design stage.  
The following sections present the details of our research methods, implementation, verification, and results. Also, findings from the interfacing of BIM and OOPM\(-\)BEPS for visualization are discussed. In this research, the terms \"building information modeling\" and \"building information models\" may both the abbreviated as BIM and used in different contexts.