Aspects of BIM-to-BEM information transfer: A tale of two workflows

Abstract

Achieving seamless transfer of information from BIM (Building Information Modelling) to BEM (Building Energy Modelling) has been the objective of multiple efforts. Nonetheless, to improve the state of art in this area, further efforts are needed. To this end, the examination of existing workflows for automated BIM-to-BEM information transfer can be useful. In this context, the present paper reviews available semi-automated approaches for information transfer from IFC-compliant BIM tools to a state-of-the-art building energy simulation application. The starting point of the case study is a synthetic building, which is modelled in two BIM-authoring tools. These models are subsequently exported to the data exchange format IFC, which are in turn transformed into the Input Data Files (IDF) of the simulation tool. The integrity and validity of the resulting geometry and semantic data are analyzed. Moreover, the simulation results obtained based on the two IDF instances are compared with a manually generated base case model. The findings of the case study point to: i) various challenges and constraints with regard to the generation of BIM models intended for subsequent export to BEM; ii) specific issues concerning the transferability of geometry and semantic data from IFC to IDF via the selected workflows; iii) inconsistencies in the resulting simulation results. Moreover, the case study provides pointers to enhancement possibilities of specific aspects of the examined workflows.