In coming years, there is a legal commitment for all the countries of Europe to improve the energy efficiency of buildings, which boils down to constructing nearly zero-energy buildings (nZEBs), buildings that consume the minimum energy. The EU Directive 31/2010 establishes two key deadlines: All public buildings must be nZEBs from 1 January, 2019, and by 1 January 2021, all new buildings must be nZEBs. “It is only one year until the first commitment, and yet many countries are a long way from meeting this level of energy efficiency in buildings. The countries that have made the most progress in this challenge are in central and northern Europe,” explained Juan María Hidalgo, co-author of the study.