Solar photovoltaic (PV) energy has emerged as a key renewable energy source, driving the global transition to a sustainable energy future. However, conventional PV systems face challenges due to the increase in panel temperature during operation, resulting in efficiency losses over time. A promising approach to mitigate these challenges is the adoption of photovoltaic-thermal (PV/T) systems, which integrate thermal collectors to harness the residual heat generated by solar panels. This article proposes a methodology for the efficient sizing of residential PV/T systems, considering both electrical and thermal aspects. The methodology aims to fill an existing gap in the field, offering a comprehensive framework for proper sizing of these systems, thus contributing to a more sustainable energy future.