GBXML as BIM interoperability schema for building energy assessment

Whereas, Building Information Modelling (BIM) enables smart integration, collaboration, precision, quality and efficiency in project delivery, its application does not come without challenges such as high cost of BIM software  and training, resistance to change, legal barriers, interoperability problems, among others. Thus, this study aimed at proffering solutions to problems associated with BIM interoperability. To achieve this, Revit Architecture BIM software was used to generate an academic building’s 3D architectural model which was subsequently exported using the Industry Foundation Classes (IFC)and Green Building eXtensible Markup Language GBXML schemas, into the Integrated Environment Solution <Virtual Environment> (IES VE) software, assessment of components and geometry. Results of interoperating the model established that the IFC model was not consistent with the architectural form of the building, whereas, the GBXML model produced an architype of the architectural model. Hence, the GBXML model was used for the energy assessment. Further, from the findings of the assessment, the building under consideration has a total energy consumption of 106.32 kWh/m2; this is well in excess of the indicative target of 64.62 kWh/m2. Accordingly, the building’s CO2 emission rate of 39.2 KgCO2/m2 exceeds the target emission value of 21.3 KgCO2/m2 for a building in its class (notional). These high energy rates are due to the dependence on fossil energy sources and the absence of renewable energy sources such as photovoltaic systems, wind turbines, solar thermal systems, etc., that serve as CO2 sinks and means of supplementing the fossil sources of energy generation. Finally, the overall performance of the building is rated as “C”.