Energy Efficiency First (EE1st) principle consists in prioritising measures that make more efficient use of the energy already available when more cost-effective and to avoid energy waste.

As highlighted in the report entitled "Energy Efficiency First: 2023 status. EU policy update and pilot country analysis", to seriously adhere to the principle, it is necessary to implement measures that also apply it to the building sector. These measures include the adoption of instruments such as Building Renovation Passports.

The report gives a summary of the EE1st principle and how it's being put into action within the European Union, concentrating specifically recent policy developments and pilot projects in Croatia, Italy, Greece, and Poland.