In recent years, halide-based perovskite solar cells (PSC) have caught worldwide attention since their power conversion efficiency (PCE) has surpassed 25% with low fabrication cost and high scalability. The semi-transparent PSC (ST-PSC) is suitable for building-integrated photovoltaic (BIPV) applications, especially for solar windows. The ST-PSC must demonstrate a reasonable balance between PCE and transparency in the visible region for solar windows, which is inversely proportional to each other. This work studies ST-PSC based on methylammonium lead triiodide (MAPbI3) as solar windows using the General-Purpose Photovoltaic Device Model (GPVDM) and OPAL 2 as the simulation platforms. Parameters such as methylammonium lead triiodide (MAPbI3) thickness, silver (Ag) contact thickness and indium tin oxide (ITO) transparent contact thickness are investigated in relation to the PCE and average visible transmission (AVT). The results demonstrate that the ST-PSC with MAPbI3 thickness of 500 nm and ITO bottom transparent contact of 100 nm leads to PCE of 22.85% and AVT of 11.36%. These parameters represent the best results obtained in this work.