Generating urban fabric in the orthogonal or non-orthogonal urban landscape

Urban designers find it virtually impossible to (re)construct self-organising urban fabric formed by a synthesis of various builders. Here we show how generic, bottom-up grammars represent historic urban fabric in a unique context, and how shape rules are embedded in the evolutionary context. This paper generalises and formalises a context-free grammar and a context-sensitive grammar to describe and design two broadly categorised (i.e. orthogonal and non-orthogonal) urban patterns. Both grammars are constructive and employ morphological parameters to govern the patterning towards a desired form. The context-free grammar describes the density and aggregation of built forms while the context-sensitive grammar represents the interactions between streets and plots. Both grammars were applied to preserve the figure-ground relationship and proved effective in designing complex urban fabric.