We speculate on a possible CAAD future that deploys and extends paradigms of natural growth and cellular development to an extent that would allow the planting and growth of man-made structures. This approach is based on the translation and expression of digital data structures into artificial physical form and the building of structures by decentral means. In such a scenario, generative and evolutionary architecture could seamlessly blend into building construction. As a discussion of as yet unavailable future technologies and methodologies the proposed remains at a “sketchy” level and must largely limit itself to preliminary and speculative considerations. In order to restrain the scope of this paper to the area of building design and construction, we focus on subway development and discuss possible cellular approaches to this particular field emphasizing aspects of functional aesthetics. We encourage the reader to take this example as a point of departure only, to generalise our explanations and to apply them to other building types. We support our discussion with findings made in software simulations of humandesigned cellular growth processes.