BIPVT is an application where solar PV/T modules are integrated into the building structure. System design parameters such as thermal conductivity and fin efficiency, type of cells, type of coolant and oper-ating conditions are factors which influence the performance of BIPVT. Attempts have been made to improve the efficiency of building-integrated photovoltaic thermal (BIPVT). A new design concept of water-based PVT collector for building-integrated applications has been designed and evaluated. The results of simulation study of amorphous silicon (a-Si) PV/T and crystalline silicon (c-Si) module types are based on the metrological condition of Malaysia for a typical day in March. At a flow rate of 0.02 kg/s, solar radiation level between 700 and 900 W/m 2 and ambient temperature between 22 and 32C, the electrical, thermal and combined photovoltaic thermal efficiencies for the PV/T (a-Si) were 4.9%, 72% and 77%, respectively. Moreover, the electrical, thermal and combined photovoltaic thermal efficiencies of the PV/T (c-Si) were 11.6%, 51% and 63%.