Ecorys, Fraunhofer ISI and the Wuppertal Institute did a study for the European Commission as a technical support for the preparation of the upcoming Recommendation on Energy Efficiency First.
Their report entitled “Analysis to support the implementation of the Energy Efficiency First principle in decision-making” has been published by the Publications Office of the European Union:
https://op.europa.eu/en/publication-detail/-/publication/b9cc0d80-c1f8-11eb-a925-01aa75ed71a1