Checking spatio-semantic consistency of building information models by means of a query language

Abstract

ABSTRACT: One of the characteristic features of object-based Building Information Models is the close integration of geometrical and semantic information into one model. This concept is thoroughly implemented by the Industry Foundation Classes (IFC), a comprehensive data model designed to provide a sound foundation for complex data exchange scenarios. Besides the provision of a large variety of data types for capturing the semantics of building elements and spaces, the IFC also allows to define relationships between building elements and/or spaces, respectively. In particular, a spatial aggregation hierarchy can be modeled by means of the relationship IfcRelAggregates successively applied to space objects. However, today no validation options exist to check whether the semantically defined aggregation hierarchy complies with the geometrical setup of the individual spaces and building elements. This lack of consistency between the semantic and the geometric part of the BIM model may lead to serious data interpretation errors on the receiving side. To prevent this, we propose a new method for validating the spatio-semantic consistency, which is based on the usage of the Query Language for Building Information Models (QL4BIM) which on the one hand provides means for accessing the IFC object model and on the other hand provides high-level spatial operators, such as Disjoint, Touching and Containing. The formulation of corresponding queries allows to verify the spatio-semenatic consistency of the IFC model. The paper discusses application scenarios and provides a number of ostensive examples.