A novel evolutionary system used for the production of design information for digital fabrication is presented. This program generates information for physical construction as architectural models of double-curved walls built from unique masonry units. We present a series of computer programs and physical models as examples of straight and curved walls generated from an evolutionary system built for design. The wall examples here are built of non-uniform, interlocking units. This project is an exploration of evolutionary design tools that construct double-curved structures in CAD for fabrication with a 3D printer.