One fifth of homes in Galway city and county have a BER rating of D or lower.
That's according to the CSO's Domestic Building Energy Report for 2024.
Building Energy Ratings compare the energy performance of different dwellings on a like-for-like basis.
The ratings can be used as an indicator of the running costs and carbon emissions associated with heating the home to a comfortable level.
It rates the home on a scale from A-G, with A being the most energy-efficient, and G being the least energy-efficient and therefore having higher bills.
The report shows over 8,000 domestic houses throughout the city and county have a BER Rating.
Just two percent of homes in the city, and 5 percent in the county have the top grade - A1.
While on the opposite end of the scale, 3 percent of homes in the city have the lowest grade of either F or G, while the percentage figure is 8 percent for the county.
