BimSPARQL: Domain-specific functional SPARQL extensions for querying RDF building data

In this paper, we propose to extend SPARQL functions for querying Industry Foundation Classes (IFC) building data. The official IFC documentation and BIM requirement checking use cases are used to drive the development of the proposed functionality. By extending these functions, we aim to 1) simplify writing queries and 2) retrieve useful information implied in 3D geometry data according to requirement checking use cases. Extended functions are modelled as RDF vocabularies and classified into groups for further extensions. We combine declarative rules with procedural programming to implement extended functions. Realistic requirement checking scenarios are used to evaluate and demonstrate the effectiveness of this approach and indicate query performance. Compared with query techniques developed in the conventional Building Information Modeling domain, we show the added value of such approach by providing an application example of querying building and regulatory data, where spatial and logic reasoning can be applied and data from multiple sources are required. Based on the implementation and evaluation work, we discuss the advantages and applicability of this approach, current issues and future challenges.