The urban fabric of the Islamic Mediterranean is the main concern of this research paper. It presents a deeper focus on al-Kairawan medina, sited in Tunisia, interpreted as exemplary case study, for the North Africa and, in absolutely, for the Muslim cities in the Mediterranean basin: it is a significant UNESCO World Heritage Site. The critical reading of the interrelationships among building type and building tissue allows to analyze the aggregation phenomenon of the courtyard houses, extricating its structural complexity. The topological experience of the measured architectural surveys and their relating drawings are the main tools of knowledge to investigate the typological, morphological and constructional characteristics of the medina, at both urban and architectural scale, with particular reference to the force of the building plot. Traditionally associated with the Middle East, courtyard housing is not only one of the oldest form of domestic architecture, but it is possible to consider this cultural heritage as an architectural act par excellence: a “living material” to use for a new reflection about the architectural and urban design in the development of the future city.