A framework for the generation and fabrication of architectural massing designs is presented. The framework consists of a computer program, which generates designs based on shape grammars, and rapid prototyping technologies that produce physical models of generated designs. The goal is to illustrate how geometrically complex designs, difficult to produce by hand, can be generated based on a few basic shapes and rules. The software developed uses Java, Open Inventor and cutting-edge 3D graphics technology. The extension of the proposed framework to one using the World Wide Web is briefly discussed.