Kildare has the highest number of homes with the best energy rating.
It’s followed by county Dublin and Meath, according to the CSO.
Just 4% of properties in Donegal have the highest energy A rating while 8% have a G rating.
20% of homes in Kildare which have been tested for a BER rating were given an A standard, while Kildare and county Dublin have 19% and for Wicklow it’s 15%.
The Building Energy Rating calculates a house’s efficiency.
Roscommon and Leitrim have the highest proportion of G ratings – which is the worst awarded.
Both counties have 12% G rated – followed by Tipperary on 11%, and Mayo and Westmeath with 10%.
Longford and Leitrim have the fewest BER ratings, while Dublin’s postal districts have the most with 229,000.
C2 and C3 are the most common ratings nationally at 12%.
In total over 1 million BER ratings have been given out since 2009.