The duty to implement an Individualised Heating Cost system is based on articles 9, 11 and 13 of the European Energy Efficiency Directive. 16 countries have enacted article 9 of the Energy Efficiency Directive into national law, including France as part of the ELAN Act. From now on, every dwelling in collective housing units must be fitted with a device used to be aware of
and control energy consumption. This is part of the individualisation of energy costs.