Homes in Wales have become significantly more energy efficient over the last decade, with social housing having the highest percentage of dwellings in EPC bands C or above.
Mae effeithlonrwydd ynni cartrefi yng Nghymru wedi gwella’n arwyddocaol dros y degawd diwethaf, gyda thai cymdeithasol yn dangos y canran uchaf o anheddau ym mand C neu uwch