The contemporary city is (re)produced in fragments through numerous typological variations. However, the current practice of spatial planning has yet to suggest effective control mechanisms to steer the piecemeal (trans)formation of cities. This paper argues for parametric modelling as a method of guiding fragmentary developments towards the pluralist production of coherent urban fabrics. Following the parametric definition of the basic morphological codes, the paper discusses the computational capacity of parametric modelling to simulate multiple variations in local fabrics and their consecutive integration within a larger context. The proposed model is tested in the context of Istanbul, Turkey.