||For occupants of commercial real estate, energy costs for electricity and heating represent a significant portion of the service charges. A typical heating installation often using fossil fuel and the purchase of electricity generate costs that are strongly depending on the prevailing market conditions and are subject to a constant increase as all trends show. Furthermore, after the nuclear disaster of Fukushima, worldwide it came to a rethinking of nuclear power as a common energy source. This led to the historic, globally unique and radical decision of the German government for an energy transition, what soon will result in a further increase of the utility costs of German real estate. The transition requires a development of renewable energy in the long term as well as new approaches to energy storage. The power grids are medium and short term to expand, which initially will affect the security of energy supply as well as lead to rising electricity costs. Contemporary real estate is subject to high demands of today's building requirements. However, especially in the large number of property based on old standards there is need for action. In addition to the renovation of the building envelope and installation of an efficient heating system supported by renewable energy, the use of a decentralized energy supply by power-heat cogeneration for appropriate property should be taken into account. This may partly lead to decouple itself from the development of the market and in the long run generate significant user-side savings. Therefore, the objective of this research is to systematize existing commercial property on possibility and feasibility to be converted to decentralized energy supply in order to reveal the optimal benefit cost ratio. Based on full cost, potential variations are examined applying comparative investment calculations. Practical benefit of this work will be to present distinct savings of operating and utility costs for most portfolio properties and to reach an informed investment decision.