The German regulations governing the energy efficiency of buildings and the building technology installed in them (Energieeinsparverordnung, or EnEV) were further tightened on 1 October 2009. This new version, EnEV 2009, applies to building projects for which the developer or owner submitted a building application or notice of building works on or after 1 October 2009. EnEV 2009 specifically promotes energy-efficient buildings and building technology. In addition, since the start of 2009, new builds – and in some instances also larger extensions and renovations – have had to cover a part of their energy demand for heating, hot water and cooling from renewable sources.