Abstract The integrated retrofitting of building heritage is a high interesting topic in Europe lately. Many calls of the researching program H2020 is focused on this topic. This work deals with a new technology that improve seismic and energetic performance of existing buildings by operating only on the outer surface. The system consists in two layers of insulating material and between them a seismic resistant layer made with in-situ cast concrete. The structural connection is made with steel screws fixed on the existing structure and embedded in the cast concrete. The resistance and the stiffness are improved, the displacement is reduced and so is the damage of the existing structural elements. The building vulnerability is then reduced. Analytical and numerical studies were carried out to assess the structural seismic performance. First a feasibility study has been conducted, analyzing different geometric configurations and boundary conditions. Analytical and numerical buckling analysis of thin concrete slabs were performed, and the results are presented. Then a sensitivity analysis was conducted to determine the sizing of retrofitting to the change in the intensity of seismic action and the height of the building. Referring to the numerical and analytical results, a set of quasi-static cyclic tests on real-scale specimens was performed and the results are presented.