Following the archaeological investigation of the topographical layout of L'Aquila during the Norman, Swabian and Angevin periods, the types of residential buildings in this border town between the Papal States and southern Italy are presented. The volume also analyses the construction techniques used for the walls and architectural elements, together with their decorative features and the anti-seismic measures adopted after frequent earthquakes or as a preventive measure. The analysis of the contexts and the use of the stratigraphic method allow the transition from relative to absolute chronology. The quality of the structures is also analysed in relation to the social status of the users, the topography and the territorial divisions of the city. The last chapters are devoted to the investigation of the original elevation profile in comparison with the current one and to the underground settlement or service structures that are widely present in the city as well as in the surrounding area.