1) The document presents a method for improving BIM search engines by exploiting relationships between objects in 3D models. It uses graph theory to represent models as nodes and connections. 2) The method was tested on a Revit model containing 7,000 3D objects and 20,000 information objects. Different relevance measures were compared that took into account single object relevance, related objects, and neighbor objects. 3) For single keyword queries, the basic relevance measure achieved a maximum recall of 0.08 with perfect precision. For multiple keyword queries, maximum recall was 0.567 and average precision was 0.871. The expanded relevance measures did not significantly change search results due to the limited output of 250 items.