Building information modeling (BIM) may advantageously be used to support life-cycle management of engineering structures. The Industry Foundation Classes (IFC) are a standardized BIM data format issued by the International Organization for Standardization to describe engineering structures, such as buildings, tunnels, and bridges. Although often employed for describing basic features of structures, the IFC standard is not capable of sufficiently describing the planning procedure of wastewater treatment plants, which is determined by functional aspects. This paper presents an IFC schema extension that supports BIM-based planning of wastewater treatment plants. A semantic model, serving as a formal basis for the IFC schema extension, is defined that contains the semantics describing the information used for planning of wastewater treatment plants. The IFC schema extension proposed in this study enables BIM-based description of wastewater treatment plants in compliance with the IFC standard, and it may serve as basis for wastewater treatment plant simulations.
