In the European economic area the qualified table of rental has established itself as authentic decision guidance regarding rent levels of cities and communities. With the ecologically qualified table of rental a new era will start in Germany. Besides the integration of the housing quality features such as property type (detached house, semi-detached house, multifamily house, etc.), size (m≤), fit-out (heating system, floor finishing, etc.), design (architecture) and location the so called ecologically qualified table of rental integrates ìthermotechnical building equipmentî. As the ìthermotechnical building equipmentî can not be integrated directly into the statistic analyses of the rental table, it needs to be operationalised via a primary energy ratio. The ecologically qualified table of rental is a promising approach to increase fairness in rent levels and at the same provides a framework for the implementation of energy saving measurements for rental housing. Highlighting the new approach in the compositions of the residential rental table, application of the new feature ìthermotechnical building equipmentî within the determination of the comparable rents as well as the financial consequences for landlord and tenant will be dealt with as well as a critical evaluation.