Abstract: At present, whether in a local BIM model library or on an online BIM model sharing
website, practitioners can only obtain the required BIM models by searching and reading them one by
one manually. With the increasing number of models, it takes much time and labor to obtain models
that meet the requirements. In this light, a component-level BIM model similarity calculation method
was proposed. Based on the components of the model, this method used the industry foundation
classes (IFC) files in the BIM universal interactive format as the data source and the universal data
standard IFC 2×3 as the data foundation. First, the geometric information and semantic information of
the components in the model were extracted, and the improved oriented bounding box (OBB)
collision detection algorithm was used to find connected components. Then the BIM model was built
as an adjacency graph model with the components as vertexes and the connection relationship among
components as edges, and he graph editing distance algorithm was used to calculate the edit distance
of the adjacency graphs. Finally, the similarity between different BIM models was calculated. Based
on the similarity of component-level BIM models, the retrieval speed and accuracy of BIM models
can be greatly improved.

Key words: building information modeling, similarity model, similarity calculation, oriented bounding box, graph edit distance