The aim of this paper is to analyse the benefits deriving from the replacement of the glazed façades of an office building located in Palermo (Sicily) with a new translucent BIPV envelope made of multifunctional glass block panels integrated with Dye-sensitized Solar Cells (DSCs). The analysed 11-storey building is cladded by a curtain wall determining high management costs, especially during summer, in order to maintain indoor comfort. After the design of the building envelope and of the components for the connection of the glass block panels with existing load bearing structure, the energy performance of the building, before and after the replacement of its envelope, were analysed with the support of Design Builder software. Other software tools – like Therm, Window and Optics – were used to calculate more in detail the thermal properties of the building envelope. The results of the energy performance simulations on the current state were compared with those deriving from the installation of the new envelope made of BIPV glass block panels. Besides the clean electricity production, a significant reduction in building energy consumption related to air conditioning systems was registered, due to the shading effect and solar gain reduction provided by the DSC-integrated glass blocks.