Under CopyrightChlechowitz, MaraMaraChlechowitzReuter, MatthiasMatthiasReuterEichhammer, WolfgangWolfgangEichhammer2022-05-172022-05-1716.2.20222021https://publica.fraunhofer.de/handle/publica/30136610.24406/publica-fhg-301366en303600An Indicator based Approach to the Energy Efficiency First Principlereport