The following paragraphs report on the study of the seismic response of a urban building block in Faial, Azores, located in Horta downtown, next to the Town Hall. The work fits within the framework of studying strengthening schemes suitable for the reconstruction process of a town damaged by an earthquake action and includes numerical modelling of all the block buildings with calibration of material/structural parameters based on ambient vibration tests. The study aims at understanding a number of issues likely to influence the global block behaviour and the local response of individual houses, namely the group effect of adjacent buildings, the in-plan stiffness of floors and/or roofs and the presence of localized strengthening interventions in selected zones of the block