Shape grammars have been developed to codify a specific type of artifact – Queen Anne houses, Buffalo bungalows – or the style of a particular designer – Andrea Palladio, Frank Lloyd Wright, or Álvaro Siza Vieira. However, these specific grammars fail to encode recurrent design moves or features that are above the particularities of a specific design style or the idiosyncrasies of a specific designer and, therefore, are common to a larger category of designs and maybe reutilized and incorporated in the definition of new, specific design languages. To overcome these limitations, the notion of generic grammars for defining design domains is introduced. Its application to the urban design domain is illustrated by showing a generic grammar implementation resulting in a City Information Modeling platform composed of a parametric design interface connected to a geographic database.