Cymhwyso gofynion effeithlonrwydd ynni
12. Yn rheoliad 21(5) yn lle “European Parliament and Council Directive 2002/91/EC of 16 December 2002 on the energy performance of buildings” rhodder “European Parliament and Council Directive 2010/31/EU of 19 May 2010 on the energy performance of buildings (recast)”.