New figures from the Central Statistics Office show that homes built between 2015 and 2019 were considerably more energy efficient than in previous years.
97% of homes built between 2015 and 2019 were given an "A" rating compared with 36% for homes in 2010 and 2014 and just 1% in 2005-2009.
The CSO said that Dublin County had the highest combined "A" and "B" ratings at 29%, while Roscommon had the lowest proportion of combined "A" and "B" ratings at 7%.
A total of 24,939 Building Energy Rating (BER) audits were reported in the third quarter of this year compared with 21,896 in the three months from July to September last year - an increase of 13.9%.
The CSO said the increased could be due to factors such as an increase in new dwellings, updating of old BER certificates as well as new renovation work.
Meanwhile, mains gas was the main space heating fuel used in 54% of the dwellings completed during 2015-2019 and with a BER audit.
This marked an increase from 2000-2004 when 41% of dwellings with a BER audit used mains gas.
The CSO noted contrasting trends for heating oil and electricity with 36% of 2000-2004 built dwellings using heating oil compared with 5% for dwellings built in 2015-2019.
In contrast usage of electricity increased from 19% in 2000-2004 to 41% in 2015-2019.
