1. Directive 2010/31/EU of the European Parliament and of the Council of 19 May 2010http://www.buildup.eu/sites/default/files/content/EPBD2010_31_EN.pdf
2. Study on the Energy Savings Potentials in EU Member States, Candidate Countries and EEA Countries. Final Report for the European Commission, Directorate-General Energy and Transport, 2009https://ec.europa.eu/energy/sites/ener/files/documents/2009_03_15_esd_efficiency_potentials_final_report.pdf
3. BREEAM Refurbishment Domestic Buildings. Technical Manual SD5072-2012-3.2, 2012http://www.breeam.com/domrefurbmanual
4. HQEhttp://www.behqe.com