The use of prefabricated modules has the potential to increase the efficiency of onsite construction activities, as well as the adaptability of buildings. However, such modules currently require a degree of repetitiveness to which many clients object. To resolve this conflict, a graph-based methodology is proposed that decomposes the design into non-repetitive modules that can be preassembled offsite, without restricting the design in advance. Such modules contain components that have similar future replacement rates, and a limited number of connections to other components. A clustering algorithm is applied on data from BIM tools for an optimal definition of the modules and their interfaces. A computer program is developed to allow the automated application of the methodology in large and complex projects. The research demonstrates that graph-based models can be useful for representing and analyzing construction projects. A graph-based approach has the potential to be successfully applied in additional areas, in order to provide project management tools. (C) 2015 Elsevier B.V. All rights reserved.