Abstract The installation of solar collectors applied or integrated into the building envelope may represent an interesting opportunity to increase the fraction of the building energy demands supplied through solar energy. In particular, building solar thermal facades (BSTFs) could be very useful in high-rise buildings, which do not have sufficient spaces where to install a solar plant. This paper aims to evaluate the energy performances of building solar thermal facades (BSTFs), constructed with two distinct types of solar collectors, flat plate (FPC) and evacuated solar collectors (ETC), through transient simulations, carried out with TRNSYS software, under different climate conditions. Moreover, an economic and LCA analysis on the two types of examined BSTFs were developed. Additionally, this study presents a preliminary investigation on a prototype of ventilated building solar thermal facade (v-BSTF) built in Ragusa. The results of such analysis highlight that BSTFs can represent suitable systems for the DHW production with great environmental and economic conveniences due to the short energy and CO2 payback times.