The post-earthquake inspections for the assessment of buildings’ usability have a key role in the post-earthquake emergency phases. In particular, a primary importance is given to the damage and usability assessment of public buildings, which is crucial for a quick recovery of the social activity. A significant contribution in the usability evaluation of such buildings (i.e. schools, hospitals, strategic infrastructures and historical and monumental heritage buildings) and churches was given by the ReLUIS-Laboratories University Network of seismic engineering-consortium, a competence centre of the Civil Protection Department, in the post-earthquake emergency phase of the recent central Italy earthquake. The in-situ surveys were carried out by teams of surveyors made up of experts from a list of ReLUIS researchers mobilized in accordance with emergency procedures in case of earthquake. The seismic sequence involved four significant events: M6.0 August 24, M5.9 October 26, M6.5 October 30, and M 5.5 January 18; thus several inspections were also repeated in order to evaluate the cumulative effects of seismic actions on the damage to constructions. The results of ReLUIS activities are herein presented and discussed.