Thermal comfort is regarded as the most important issue in residential buildings. To verify the thermal performance of the envelope components used for the promotional apartments in Algeria, whether they are adapted to the hot and dry southern climate, or the Mediterranean climate, and to understand the effect of fixed and combined horizontal and vertical shading devices of different dimensions (12 cm, 25 cm, and 50 cm) on the indoor thermal comfort of these apartments, two main climatic zones have been considered in this study, the first is a desert climate of (Biskra, Ghardaïa, and Ouargla), while the second is a Mediterranean climate of (Algiers, Oran, Bari, and Naples). The methodology of this research was based on a comparative approach to the outcomes of a stay in an apartment in Biskra, which was looked at as a model for other desert and Mediterranean cities, based on the operative temperature data of different scenarios obtained through several simulations, which conducted by the use TrnSys software. The findings suggest that the double-walled hollow brick envelope causes a very severe indoor thermal environment (To<29) in dwellings located in desert regions such as Biskra, Ghardaïa, and Ouargla. In addition, the findings also suggest that shading devices are more effective for apartments located in the Mediterranean region (Algiers, Oran, Bari, Naples) than those located in the desert region. In the desert region, the use of mechanical cooling devices in the summer period is considered the most adequate solution to ensure the occupants’ thermal comfort. To identify the most optimal shading device models, future research based on the parametric simulation of kinetic shading devices is needed.