Photovoltaic-thermal (PVT) collectors are hybrid solar collectors that convert solar and ambient energy into thermal and electrical energy. Integrated PVT-HP, in which PVT collectors are combined with a heat pump, offers an efficient and renewable option to replace conventional fossil fuel-based energy systems in residential buildings. Currently, system concepts in which the selection, design and control of the components are aligned towards the system performance are lacking. The development of a system model enables the comparison of a variety of system parameters and system designs, informed decision making based on the energetic performance and the market diffusion of PVT-HP systems. This contribution presents a simulation model of a PVT-HP system. By means of numerical simulations, with simulation program TRNSYS, the energetic performance of a PVT-HP system and the system components are investigated. It is shown that the PVT-HP can cover the annual energy demand of a residential building. The corresponding Seasonal Performance Factor (SPF) is equal to 3.6. Furthermore, the effect of varying weather conditions, occupancy and building orientations on the performance of the reference system is analyzed. The SPF for the investigated scenarios varies between 3.0 and 3.9. Lastly, two system parameters, the PVT collector area, and the PVT collector type are varied as an initial step in the optimization of the system performance. To sum up, the presented PVT-HP model is suitable for dynamic system simulation and the exploration of the system concepts. The simulation study shows that a PVT-HP system can cover the annual energy demand of a residential building. Lastly, parametric variations showcase the optimization potential of PVT-HP systems.