The future of the real estate market in Europe requires the rehabilitation of existing residential areas in order to respond to new life-styles and dwelling requirements. In this research both shape grammar and space syntax are used as part of a rehabilitation methodology as tools to identify and encode the principles and rules behind the adaptation of existing houses to new requirements. (Eloy, 2012) In addition to defining a general methodology applicable to all the building types, the study focused on a specific type, called “rabo-de-bacalhau” (“cod-tail”), built in Lisbon between 1945 and 1965 for which a specific methodology was generated. Ongoing work focuses on the generalization of the transformation grammar using the same general framework of rules and integrating specificities of different building types (Eloy and Duarte, 2012), the development of tools to generate functional programmes (Pedroso et al, 2014) and the development of tools to automate the design layouts (Strobbe et al, 2016). The development of a general transformation grammar would enable the rehabilitation of various types of housing buildings. An architectural challenge, such as the large-scale refurbishment of existent housing stocks, that require too much design efforts to be logistically or economically feasible, can be addressed by a stand-alone generative system such as shape grammars. Considering of design solutions achieve by the transformation grammar, there is evidence that those refurbishment designs have the same architectural quality as designs done by human architects (Eloy and Vermaas 2014b). This design tool could be made available as a web tool directly to the apartment inhabitants and therefore enabling them to define their own house (Eloy and Vermaas 2014a). Recent work focus on the transformations performed by inhabitants in existing housing settlements and how can shape grammar can be a tool to both assure design quality and enable co-design (Eloy, Dias, Vermaas, 20...