The patchwork theory is a theory of block size and shape, picking up the local distortions in urban space induced by the placing and shaping of physical structures. This explains the phenomenon that the background urban network is partitioned into a patchwork of local areas.
Hillier, B., Turner, A., Yang, T., Park, H-T. (2007, 2010) Metric and topo-geometric properties of urban street networks: some convergencies, divergencies and new results. The Journal of Space Syntax, V(1) 2, 258-279. pp. 259