A library of prefabricated parts and assemblies, i.e. module library, can help a firm in the construction industry transition to a more industrialized and product-oriented approach. However, existing approaches to manage such libraries are oriented around single-use projects. There is need for a more flexible data structure to support storage, analysis and reuse of design information. This paper proposes a graph-based approach to develop a module library. The approach includes a graph representation of modules, a graph database development, and a graph-based similarity analysis. The proposed approach is validated using a prefabricated timber panel system via a web-based application. Implementation demonstrates a more efficient process for bill of material generation and identifying the impacts of design changes.