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2. European Parliament and Council Directive 2002/91/CE on the energy performance of buildings. Available online at: https://eur-lex.europa.eu/legal-content/LVN/TXT/?uri=celex:32002L0091 (accessed on July 4, 2018).
3. European Parliament and Council Directive 2010/31/UE on the energy performance of buildings. Available online at: https://eur-lex.europa.eu/legal-content/EN/ALL/?uri=CELEX%3A32010L0031 (accessed on July 4, 2018).
4. European Parliament and the Council Directive 2018/844/EU of 30 May 2018 amending Directive 2010/31/EU on the energy performance of buildings and Directive 2012/27/EU on energy efficiency. Available online at: https://eur-lex.europa.eu/legal-content/EN/TXT/PDF/?uri=CELEX:32018L0844&from=EN (accessed on December 18, 2018).
5. Greening existing buildings [GEB] strategies;Leung;Energy Rep.,2018