Prefabricated Modular Volumetric Architecture (PMVA) needs to combine industrial-made modules with limited dimensions due to transport restrictions to attend to programs, increase space, and generate forms. Different compositions change the position and quantity of structural components and require other attributes for the connections used to fix the modules and define the building at the building site. In this study, a connective model is proposed enabling multiple compositional alternatives along with the corresponding connective guidelines. Four generic connective sets are used to simulate and define the connective guidelines, and they are then applied to three types of prisms: rectangular, trapezoidal, and triangular. The methodology, which is based on shape grammar, confirms that the use of compositional alternatives with this system depend on the geometric and constructive attributes of the connective set used to fix the modules together. The compositional variation is therefore closely linked to a compositional-connective relation and to connective sets submitted to different degrees of adjustment. The proposed model opens the way for the industry to change the connective sets used and broaden the combinatorial capacity of chassis and thereby increase the capability for mass customization.