One-quarter (25%) of the 1.3 million dwellings with Building Energy Ratings (BER) had at least one source of renewable energy present when considering heat pumps, solar thermal systems, and solar photovoltaic panels (See Table A and Figure 1).
Solar energy, both thermal and electric, was present in 14% of BER rated dwellings by Q3 2025, or over 180,000 homes (See Figure 1, Table A, and Table 13).
By type of dwelling audited, detached houses had the highest proportion of solar energy use (23%), while apartments had the lowest (5%) (See Table 13).
Heat pumps were installed in 13% of all rated dwellings. Newer builds were more likely to include heat pumps, including 85% of those built since 2020 (See Table 14).
Mains gas was the most commonly reported space heating fuel (35%), closely followed by heating oil (35%) (See Figure 3 and Table 9).
Electricity was the main space heating fuel for 93% of dwellings built since 2020, compared with 25% of the total rated stock (See Figure 3 and Table 9).
A ratings were received by 94% of dwellings built from 2015-2019, and 99% of those from 2020-2025, compared with 17% of the total rated stock (See Figure 2 and Table 2).
The category of solar energy used in this release includes both solar thermal installations for heating and solar photovoltaic installations for electricity generation.
The actual number of renewable energy installations will likely be higher than those counted in this release. Not all dwellings have received a BER assessment, and among those that have, a renewable energy source may have been installed after their most recent BER assessment.
Please refer to the Background Notes for more details on definitions and coverage.
Of the BER rated households where the main space heating fuel can be identified, 25%, or over 320,000, had at least one source of renewable energy present when considering heat pumps, solar thermal systems, and solar photovoltaic panels. The proportion of rated dwellings with both a heat pump and solar energy was 2% (See Table A and Figure 1).
Newer builds are more likely to include heat pump installations, which were present in 85% of dwellings built in 2020-2025 (See Table A and Figure 1).
Solar installations outnumbered heat pump installations in dwellings built before 2020 (See Table A and Figure 1).
Tables 13 and 14 contain further breakdowns of these percentages by county.
| X-axis label | Heat Pump | Solar Energy | Both | Neither |
|---|---|---|---|---|
| 1700-1949 | 4556 | 11714 | 1745 | 150005 |
| 1950-1977 | 5964 | 22282 | 2406 | 184986 |
| 1978-1993 | 4955 | 23794 | 2031 | 161115 |
| 1994-1999 | 3543 | 14545 | 1044 | 111227 |
| 2000-2004 | 4565 | 18592 | 1944 | 178976 |
| 2005-2009 | 5809 | 18733 | 3726 | 161336 |
| 2010-2014 | 1259 | 8413 | 1387 | 3813 |
| 2015-2019 | 21871 | 27305 | 5899 | 2245 |
| 2020-2025 | 85993 | 9594 | 9751 | 7222 |
| Table A: Percentage of BERs with Renewable Energy Installations by Period of Construction | |||||
| % of row | |||||
| Period of Construction | Solar Energy | Heat Pump | Both | Neither | Total |
| 1700-1949 | 7 | 3 | 1 | 89 | 168,020 |
| 1950-1977 | 10 | 3 | 1 | 86 | 215,638 |
| 1978-1993 | 12 | 3 | 1 | 84 | 191,895 |
| 1994-1999 | 11 | 3 | 1 | 85 | 130,359 |
| 2000-2004 | 9 | 2 | 1 | 88 | 204,077 |
| 2005-2009 | 10 | 3 | 2 | 85 | 189,604 |
| 2010-2014 | 57 | 8 | 9 | 26 | 14,872 |
| 2015-2019 | 48 | 38 | 10 | 4 | 57,320 |
| 2020-2025 | 9 | 76 | 9 | 6 | 112,560 |
| Total | 12 | 11 | 2 | 75 | 1,284,345 |
The number of domestic Building Energy Rating (BER) audits published in Q3 2025 was 42,097. This was 7% higher than the number published in Q3 2024, and the highest third quarter total for any year since 2009. In total, 1.7 million BER audits have been published from 2009-2025 (See Table 1).
Newer builds were more energy efficient than older stock. A ratings were awarded to 99% of audited dwellings built since 2020, and 94% of those built between 2015-2019. In comparison, 38% of dwellings built between 2010-2014 and 5% of the dwellings built from 2005-2009 received an A rating (See Figure 2 and Table 2).
| A | B | C | D | E | F-G | |
| 1700-1977 | 3 | 9 | 21 | 22 | 18 | 28 |
| 1978-1999 | 3 | 15 | 41 | 29 | 9 | 4 |
| 2000-2004 | 3 | 20 | 56 | 16 | 4 | 1 |
| 2005-2009 | 5 | 42 | 44 | 7 | 2 | 0 |
| 2010-2014 | 38 | 54 | 6 | 1 | 0 | 0 |
| 2015-2019 | 94 | 6 | 0 | 0 | 0 | 0 |
| 2020-2025 | 99 | 1 | 1 | 0 | 0 | 0 |
The highest proportions of A rated dwellings were in Kildare (28%), Meath (27%), and Dublin County (27%), while the lowest were in Leitrim and Cork City (both 5%). The highest proportions of G rated dwellings were in counties Roscommon (11%) and Leitrim (11%) (See Table 4).
In the Dublin postal districts, the highest proportions of A ratings were in Dublin 18 (43%), Dublin 13 (31%), and Dublin 20 (28%). The lowest level of A rating was 7% in Dublin 07 (See Table 5).
The most common main space heating fuel in audited dwellings was mains gas (35%), followed by heating oil (35%) and electricity (25%). For dwellings built since 2015, electricity was the most common space heating fuel. Dwellings constructed from 2020 to Q3 2025 were 93% electrically heated (See Figure 3 and Table 9).
| Mains Gas | Heating Oil | Electricity | |
| 2000-2004 | 40 | 37 | 20 |
| 2005-2009 | 43 | 32 | 20 |
| 2010-2014 | 41 | 35 | 21 |
| 2015-2019 | 43 | 6 | 50 |
| 2020-2025 | 6 | 0 | 93 |
The average floor area for all rated dwellings was 117 m2. The dwelling type with the largest average floor area was detached houses (166 m2) while the smallest type was apartments (70 m2) (See Table 12).
Energy from solar electric panels or solar thermal collectors was present in 14% of rated dwellings. This proportion was highest in detached houses (23%) and lowest in apartments (5%). By county, the highest proportion of dwellings with solar energy was 23% in Meath, 21% in Kildare and 20% in Dublin County (See Table 13).
A heat pump was present in 13% of rated dwellings where the main space heating fuel was identified (See Table 14). This proportion was highest in newer builds, with heat pumps present in 85% of dwellings built from 2020 up to Q3 2025 (See Table 14).
In dwellings which have received more than one BER assessment, over 198,000 saw an improvement of at least one full letter over their initial energy rating.
Of these, 49% improved from a C rating or below in their first rating to an A or B in their most recent assessment (See Table 15).
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Statistician's Comment
The Central Statistics Office (CSO) has today (16 October 2025) published Domestic Building Energy Ratings (BER) for Quarter 3 (Q3) 2025.
Commenting on the release, Kevin Hunt, Statistician in the Climate and Energy Division, said: “The number of domestic BER assessments reported in Q3 2025 was 42,097. This takes the total number of audits published from 2009-2025 to 1.7 million, including dwellings with multiple assessments (See Table 1).
Of the 1.3 million unique dwellings to receive a BER since 2009, 17% received an A rating in their most recent assessment (See Table 2).
Proportion of Rated Dwellings with Solar Energy
Energy from solar electric panels or solar thermal collectors was present in 14% of rated dwellings.
This proportion was highest in detached houses (23%) and lowest in apartments (5%) (See Table 13).
By county, the highest proportion of dwellings with solar energy was 23% in Meath, 21% in Kildare, and 20% in Dublin County (See Table 13).
Proportion of Rated Dwellings with Heat Pumps
A heat pump was present in 13% of rated dwellings where the main space heating fuel was identified (See Table 14). This proportion was highest in newer builds, with heat pumps present in 85% of dwellings built from 2020 up to Q3 2025 (See Table 14).
Energy Ratings by Period of Construction
Newer builds were more energy efficient than older stock. A ratings were awarded to 99% of audited dwellings built since 2020, and 94% of those built between 2015-2019. In comparison, 38% of dwellings built between 2010-2014 and 5% of the dwellings built from 2005-2009 received an A rating (See Figure 2 and Table 2).
Main Space Heating Fuel
The most common main space heating fuel in audited dwellings was mains gas (35%), followed by heating oil (35%) and electricity (25%). For dwellings built since 2015, electricity was the most common space heating fuel. Dwellings constructed from 2020 to Q3 2025 were 93% electrically heated (See Figure 3 and Table 9).
Dwellings with Improved Energy Ratings
Among those dwellings which have received more than one BER assessment, over 198,000 saw an improvement of at least one full letter category over their initial energy rating. Of these, 49% went from a C rating or below in their first rating to an A or B in their most recent assessment (See Table 15).
Energy Ratings by County and Dublin Postal District
The highest proportions of A rated dwellings were in Kildare (28%), Meath (27%), and Dublin County (27%), while the lowest were in Leitrim and Cork City (both 5%). The highest proportions of G rated dwellings were in counties Roscommon (11%) and Leitrim (11%) (See Table 4).
In the Dublin postal districts, the highest proportions of A ratings were in Dublin 18 (43%), Dublin 13 (31%), and Dublin 20 (28%). The lowest level of A rating was 7% in Dublin 07 (See Table 5)."