The objective of this study is to investigate the performance of co-generation systems in commercial buildings in various regions in Japan taking into account the contribution to business continuity plan (BCP). An energy simulation tool named "BEST" was employed to calculate the energy demand of non-residential buildings under regional climatic conditions. The additional electricity for BCP were estimated based on the simulated energy demand, which indicates good agreement with the literature data. By introducing cogeneration, the possibility was evaluated quantitatively to achieve both energy savings and securing the electric power necessary for BCP. The results show that some cases can attain both of them. In addition, this study analyzed the performance of demand response (DR) by switching co-generation to an electric power-based air-conditioning system. The numerical example suggests that the operation will be effective and possible not to increase primary energy consumption even with DR.