The Act on promoting energy savings in buildings, together with three supplementary decrees (on energy labelling, inspection of boilers and heaters, and inspection of ventilation and air conditioning systems respectively) are key instruments relating to the implemention of Articles 3, 5, 7, 8, 9 and 10 of the EU Energy Performance of Buildings Directive (EPBD). The requirements relate to the energy labelling of new buildings and buildings when they are sold entered into force on 1 January 2006. Energy labelling relating to buildings when they are rented out entered into force on 1 July 2009. Rules regarding the inspection of boilers and heating systems were implemented on 1 September 2006. With regard to implementation of Article 8, Denmark has chosen option a). Inspection of air conditioning and ventilation systems has been implemented as of 1 January 2008.