The energy transition represents an essential process necessary to drive a shift towards a sustainable and balanced human-environment interaction. Within the residential building sector, this obj ective can be pursued by promoting both the utilization of renewable sources and the energy efficiency improvement of technical systems and the building envelope. In this regard, this article conducts an energy analysis to assess the reduction in energy requirements achieved by installing two Trombe walls on the south-facing wall of the variable orientation test station at the University of Calabria. The two passive systems were symmetrically positioned on either side of the existing window system. The evaluation of monthly energy requirements during the heating period was performed using the dynamic simulation software DesignBuilder. To define the optimal configuration of the Trombe walls, the influence on energy requirements associated with the materials used to construct the support structure of the Trombe walls, the type and number of glass panels forming the solar space, the size of the solar space, and the dimensions of the vents were assessed. The results show that the installation of the two Trombe walls, each consisting of two vents with an area of 0.1 m 2 and a solar space depth of 0.20 m, supported by a PVC structure and vertically bounded by three glass walls with double low-emissivity glazing (two lateral and one frontal facing south), allows for a 60.62% reduction in winter energy requirements.