Releasing the power of graph for building information discovery

Graph is considered a promising way to managing building information. A new graph-based representation of Industry Foundation Classes (IFC) data, known as IFC-Graph, has recently been developed. However, investigation into IFC-Graph is insufficient, especially for information query. This paper aims to explore the query of graph-based building information and develop a graph query tool for IFC-Graph. A series of tasks were carried out, including a) investigating the structure of IFC schema and IFC data, b) investigating graph query language (GQL), e.g., Cypher, and c) based on the previous two steps, developing a good practice and a set of query patterns tailored for IFC schema. The developed query tool is referred to as GQL4BIM. Five IFC models were used for validation, and the result shows that GQL4BIM can query individual instances and complex relations from IFC-Graph, such as spatial structure, space boundary, and space accessibility. This paper contributes to applications that require effective building information query, such as digital twin. • A graph-based query tool, GQL4BIM, was established for IFC-Graph. • Tailored patterns for IFC-Graph query were developed. • The joint use of pattern and abstraction in building information query was explored. • GQL4BIM is proved to be effective in retrieving implicit information from IFC data.