The residential sector in the European Union accounts for 27% of final energy consumption and 23% of CO2 emissions. Due to this situation, the European Union, in order to strive for greater energy efficiency and savings, has established the Energy Performance of Buildings Directive, which, in the case of Spain, takes the form of a Basic Document outlining Energy Saving in the Technical Building Code (CTE-DB-HE). The aim is to perform an energy and environmental analysis in a multi-family housing block, evaluating improvements that are the result of the implementation of the CTE-DB-HE and comparing them with the previous situation. For this purpose, five representative cases for 26 Spanish cities located in cold climate zones are analyzed. The results reveal that with the current rules, an energy demand reduction of over 60% is achieved. In addition, 65% higher reductions are obtained both in the non-renewable primary energy consumption and CO2 emissions, thereby achieving class B building status. These remarkable savings show that the right direction is being taken toward nearly zero-energy buildings (NZEBs). (C) 2017 Elsevier B.V. All rights reserved.