Retrofit of existing RC buildings with diagrids adopting a holistic- sustainable design framework

The deep renovation of existing buildings is nowadays acknowledged as a priority in order to foster safety and eco-efficiency of the European construction sector. This renovation process should be inspired by some major principles as to ensure sustainability and feasibility of the interventions, also boosting the actual low renovation rate. The introduction of diagrid exoskeletons has been recently proposed as a new holistic and sustainable technique for the deep renovation of existing RC buildings under a seismic, energy, and architectural point of view. The exoskeleton can be conceived by addressing the Life Cycle Thinking principles, not also implementing eco-efficient materials but also guaranteeing reparability, adaptability, and demountability, selective dismantling and reusability of each component at the end of life. The solution is implemented exclusively from outside the building, thus avoiding inhabitants’ relocation. Off-site prefabrication of components, as well as the use of standardized elements and connections reduce construction time and costs. A simple method for the preliminary design of diagrids, also considering sustainable principles aimed at reducing the damage along the life of retrofitted building, is here proposed.