Interoperability between building information models and software for lighting analysis

Lighting analysis models are being integrated into building information models (BIM) quickly. The BIM of the Politecnico di Torino (Polito) campus used in the Smart Energy Efficient Middleware for Public Spaces (SEEMPubS) project is an integrated representation of each building to merge architectural, structural, electrical and HVAC elements and components. In the Polito campus there are three types of buildings: historical, modern and contemporary. A special approach has been adopted to model and to exchange data between software about historical buildings because they are characterized by paints, stuccos, etc. The aim of this research was to set a parametric model able to share information without data loss, testing the interoperability between architectural software like Revit Architecture and lighting analysis software like Daysim and Radiance. As the process of exchanging data from Revit to Daysim and Radiance is not direct, Ecotect Analysis was used as an “interoperable bridge” with good results. Three different formats were tested: IFC, gbXML and FBX and for each one problems and possible solutions were analysed. Up to now, Ecotect was used in two different ways: to define material parameters before the export phase and to visualize analytical data obtained from Daysim and Radiance. In our tests some errors have occurred referring to data retention like material properties, but at present the main problems have been solved. Indications about performance of daylighting and energy consumption have been obtained, although a lot of work should still be done. The correct data exchange that we obtained enabled the optimization of the building simulation process by avoiding the need to remodel the same building in the lighting applications.