To reflect Danish implementation of the EU Energy Performance of Buildings Directive (EPBD) 2002/91/EC, the national buildings code for energy efficiency in new buildings changed on 1 January 2006. As of 2006, the the maximum energy use in new buildings is based on an energy performance calculation. New buildings will be subject to a thermal efficiency standard approximately 25-30% more stringent than that of existing buildings in all new buildings. The national building code will be tightened with 25 % in 2010, additional 25 % in 2015, and further 25 % in 2020. Methods: Calculation of buildings efficiency now involves consideration of the total energy consumption of heating, lighting, cooling and ventilation within the building frame.