Assessment and Retrofitting of Building Structures: Experimental Testing and Modelling—Editorial

Collapse of, or severe damage to, existing buildings during strong earthquakes has resulted in significant economic losses, severe injuries, and casualties. Progress made over the last few decades has had a considerable impact on the seismic safety of modern buildings designed according to new standards. However, the majority of existing buildings in southern European countries do not meet the safety requirements set by the Eurocodes. Thus, the assessment of existing buildings not designed with modern codes and the development of effective retrofitting techniques are currently of paramount importance to society. The use of accurate modelling strategies and appropriate seismic assessment methodologies is crucial to understand the behaviour of existing buildings and to develop efficient and proper mitigation measures, thus, preventing future damage, casualties, and economic losses. The effect of non-structural elements should not be neglected, since they could play a vital role in buildings’ structural performance. Another major challenge is to ensure the sustainability of renovation schemes in terms of both the environmental burden (i.e., CO2) and economic investment in seismic regions. The sustainable renovation of existing buildings typically focuses on reducing operational energy consumption and using low-carbon materials in the refurbishment process, without accounting for structural deficiencies that could leave the building exceptionally unsafe and hamper the refurbishment investment, particularly in areas prone to seismic activity. This Special Issue focuses on innovations in the context of assessment and retrofitting of building structures: experimental testing and modelling.