Back to Top

 Skip navigation

The number of BER audits performed in certain months have been adversely impacted by the COVID-19 pandemic. For further information please see the SEAI website.

Extra information
Methodology Previous Releases
International comparison:
See also:
YouTube Video
For more information on this release:
E-mail: environment@cso.ie Dympna Corry Berna Lawlor
For general information on CSO statistics:
information@cso.ie (+353) 21 453 5000 On-line ISSN 2009-7441
CSO statistical release, , 11am

Domestic Building Energy Ratings

Quarter 4 2021

Table A: Number of Domestic BER certificates
number 
Period20172018201920202021% change 2021/2020
Quarter 120,13418,19319,62820,67914,582-29%
Quarter 223,00923,04123,14610,24121,966114%
Quarter 322,34421,89524,98623,26923,023-1%
Quarter 422,12822,31023,24622,93723,9604%
 
Year87,61585,43991,00677,12683,5318%
      

8% increase in Domestic BER audits in 2021

Figure 1: Number of Domestic BER Certificates published in 2019-2021
go to full release

There was an increase in the number of Building Energy Rating (BER) audits reported in 2021 when the number of completed BER audits was 8% above the number in 2020 (see Table A, Table 1, Figure 1 and Information Note). There were 23,960 BER audits reported in quarter four 2021 compared with 22,937 in quarter four 2020. This is an increase of 4% (see Table A). In the period 2009 to December 2021 just over 1.1 million BER audits have been undertaken (see Table 1).

Dwellings built in 2015-2021 were considerably more energy efficient than those built in earlier periods with 98% given an “A” rating compared with 34% in 2010-2014 and 1% in 2005-2009 (see Table 2 and Figure 4).

Dublin County had the highest combined “A” and “B” rating at 32% (see Table 4). Leitrim had the lowest proportion of combined “A” and “B” rating at 11%.

Dublin 18, with an average dwelling age of 18 years, had the highest proportion of combined “A” and “B” rating at 46% (see Table 5). The average age of dwellings in Dublin 15 that have had a BER audit done was 17 years, but the combined "A" and "B" rating was much lower at 32% than in Dublin 18. The highest proportion of combined “F” and “G” rating was 25% for Dublin 7.

Electricity was the main space heating fuel used in 56% of the dwellings completed during 2015-2021 and with a BER audit. This was an increase from 2000-2004 when 19% of dwellings with a BER audit used electricity. There was a contrasting trend for heating oil with 35% of 2000-2004 built dwellings using heating oil compared with 3% for dwellings built in 2015-2021 (see Table 9).

The average floor area of all dwellings with a BER audit was 113 square metres (see Table 11). This average size varied from 159 square metres for detached houses to 60 square metres for basement dwellings.

Table 14 examines dwellings that have had more than one BER audit carried out. In their earliest assessment only 8% of dwellings received either an “A” or “B” rating compared with 26% in their most recent assessment. In contrast, 18% of dwellings were rated “F” or "G" in their first BER assessment compared with only 4% in their latest BER assessment (see Table 14 and Figure 2).

EarliestLatest
A03
B113
B226
B3514
C1817
C21115
C31212
D11410
D2138
E194
E273
F82
G102
Earliest BER ratingsLatest BER ratings
A00
B101
B214
B3412
C1717
C2916
C31213
D11412
D2149
E1105
E283
F93
G122

Table 15 examines the representativeness of dwellings that have a BER. The data were weighted up to national level using Census of Population 2016 figures. The national level data shows that 6% of dwellings in Ireland would have received a rating of “F” compared with 5% of dwellings that have had a BER assessment (see also Figure 3). Similarly, 8% of dwellings would have received a rating of "G" compared with 7% of dwellings in the actual BER data. In contrast, 6% of dwellings would have received an "A" rating at the national level, whereas 9% of dwellings that have had a BER assessment were given an "A" rating.

National DataBER Database
A69
B111
B233
B378
C11011
C21213
C31212
D11212
D21110
E166
E255
F65
G87
National DataBER database
A23
B111
B223
B367
C11011
C21213
C31313
D11313
D21211
E177
E265
F65
G97

1Dwellings with BERs have been weighted using 2016 Census of Population data to estimate a BER profile for All Dwellings at National level (see Background Notes).

ABCDEF-G
1700-19771519241932
1978-1999174134125
2000-2004012602052
2005-200913650921
2010-201434568200
2015-20219820000
Table 1 Domestic BER Certificates (2009-2021) 1
number
Period2009201020112012201320142015201620172018201920202021Total
January4,1124,6918,5756,5316,9757,0106,5295,2625,6875,1755,5225,8843,76075,713
February6,3335,6459,0386,3128,5307,5477,6636,8686,8156,5006,8897,6204,79090,550
March8,7736,1698,9506,5188,2108,3867,2707,5457,6326,5187,2177,1756,03296,395
April8,0635,4897,7824,4478,2988,7367,5927,3997,1417,0547,2461,9966,25987,502
May7,9375,4778,8785,8818,6488,7317,7167,9568,1788,3968,3312,4517,78196,361
June8,7375,8027,4664,8657,2658,2158,0027,4487,6907,5917,5695,7947,92694,370
July8,7755,9497,2575,5367,1039,3987,6746,5617,1247,5118,3527,6088,08096,928
August7,2616,4177,5315,0456,9738,1667,6487,0297,2497,1548,2256,8896,78092,367
September7,5047,4208,8474,9658,2789,9218,3557,6657,9717,2308,4098,7728,163103,500
October6,5838,3959,5636,6878,97310,7659,2217,9278,0578,31110,8068,3989,053112,739
November6,95311,5919,6068,7949,59810,8918,4009,0108,3928,2606,1808,0678,844114,586
December6,3248,0029,4656,3616,9297,7737,3066,0765,6795,7396,2606,4726,06388,449
               
Total87,35581,047102,95871,94295,780105,53993,37686,74687,61585,43991,00677,12683,5311,149,460
1 Includes all Certificates for Dwellings
Table 2 BERs by Period of Construction (2009-2021)
% of row 
Period of ConstructionEnergy Rating Total
AB1B2B3C1C2C3D1D2E1E2FG
1700-18991012335710910143625,344
1900-1929101234571099143655,396
1930-19491123567912910122446,901
1950-1966112356811141110121672,980
1967-19771114791115161199892,195
1978-19821114913151717964359,322
1983-199300151013161917854299,400
1994-1999112612161919136431108,730
2000-200401291822201373210171,642
2005-200913112224179632110160,391
2010-20143428181142111000012,046
2015-20219811000000000076,832
               
Total913811131212106557981,179
Table 3 BERs by Type of Dwelling (2009-2021)
% of row 
Dwelling TypeEnergy Rating Total
AB1B2B3C1C2C3D1D2E1E2FG
Apartment141214127910966573,458
Ground-floor apartment71371011111213865653,926
Mid-floor apartment1241012121210107432367,065
Top-floor apartment614810101012137551055,575
Basement Dwelling503275676119930312
Maisonette1027111311999433711,090
House12391214141211544833,683
Detached house623811121211106459272,751
Semi-detached house1112612141412105444267,607
End of terrace house121261112111110656774,989
Mid-terrace house813913121010106557140,723
               
Total913811131212106557981,179
Table 4 BERs by County (2009-2021)
% of row  
CountyEnergy Rating Average age
AB1B2B3C1C2C3D1D2E1E2FGTotal
Carlow71271314131310544713,05630
Dublin 01-241014810111112117556221,09437
Dublin County18248111211109433373,76027
Kildare19138121312118433443,57922
Kilkenny62381213121210645815,76935
Laois5139121413108555814,98630
Longford2227121312141065698,27330
Louth10239161411108533628,24531
Meath1813915151197333436,98023
Offaly512510131210107781012,91734
Westmeath31381013141310655917,58432
Wexford61251013141411745731,84130
Wicklow141371112111110655728,92132
Clare3126913141411755824,47333
Cork City32491212111211766722,30645
Cork County9241114121098544789,50533
Kerry52371112121311755831,00830
Limerick City51371314141311644617,80737
Limerick County51361113141312644824,78833
Tipperary312610121212117671131,24740
Waterford City61261314141511644511,11436
Waterford County82371212131311544614,90935
Galway City61261113151512654415,29025
Galway County51371113131210655838,06229
Leitrim1127121412119667127,36834
Mayo41259131413126561025,97033
Roscommon31261114141196561211,75134
Sligo42271012121312765815,03632
Cavan31310151512118545914,41329
Donegal41261315141210655829,82631
Monaghan7238121111121164589,30135
                
Total913811131212106557981,17933
Table 5 BERs by Dublin Postal District (2009-2021)
% of row  
Dublin Postal DistrictEnergy Rating Average age
AB1B2B3C1C2C3D1D2E1E2FGTotal
Dublin 1625791011121285588,85733
Dublin 2925791111131075465,07035
Dublin 3413689101012989129,03258
Dublin 45158810101313866711,15146
Dublin 5512681011141398859,18844
Dublin 661356781113979159,16560
Dublin 6W13126789111187885,44047
Dublin 720237109121299101512,30059
Dublin 84158991011128671015,12047
Dublin 9121378991012878711,82244
Dublin 104026131513121076764,24647
Dublin 11102612121110109655412,54131
Dublin 124125791012139910911,03254
Dublin 13241591010910844328,65825
Dublin 141135899101011866510,30138
Dublin 15171410141512118321123,56017
Dublin 1612149111312131154329,60228
Dublin 177161015191312842214,54125
Dublin 1816511141411976221111,41018
Dublin 208368889121396542,43833
Dublin 226015101415161574328,01028
Dublin 24141261114131311643117,61022
                
Total1014810111112117556221,09437
Table 6 BERs by Main Space Heating Fuel (2009-2021)
% of row  
Fuel TypeEnergy Rating Total
AB1B2B3C1C2C3D1D2E1E2FG
Mains Gas825111615121184332380,581
Bulk LPG2271721171285221113,238
Bottled LPG01310131412111154591,071
Heating Oil112712151514116555352,006
Electricity26222357111275512174,682
Coal00011411141419363,234
Smokeless Fuel000001412141316406,434
Peat0011410131317401,518
Wood Pellets & Chips2411201416118632221,600
Wood Logs422333510129101028635
Solid Multi-Fuel00000127131313153631,294
               
Total813812131212106557966,293
– No dwelling received this BER for this main space heating fuel type
Table 7 BERs by Main Water Heating Fuel (2009-2021)
             % of row 
Fuel TypeEnergy Rating Total
AB1B2B3C1C2C3D1D2E1E2FG
Mains Gas825111615121184332378,641
Bulk LPG2271821171285221113,185
Bottled LPG01310131512101164581,177
Heating Oil112712151514116555349,123
Electricity25222357101175514182,612
Coal0001112512141519283,100
Smokeless Fuel00012514151518305,498
Peat0011510131317381,542
Wood Pellets & Chips2411201416117632321,575
Wood Logs332433611121091024579
Solid Multi-Fuel00000127131414163129,261
               
Total813812131212106557966,293
– No dwelling received this BER for this main water heating fuel type
Table 8 Main Space Heating Fuel by County (2009-2021)
% of row    
CountyFuel Type 
Mains GasHeating OilElectricitySolid FuelLPGTotal
Carlow3444155113,047
Dublin 01-247252210212,009
Dublin County7411141071,137
Kildare4632192143,457
Kilkenny2849147215,704
Laois32431113114,951
Longford164201138,201
Louth5631102127,947
Meath4735142136,954
Offaly11541420112,791
Westmeath14541712317,532
Wexford1681910231,712
Wicklow4136174128,598
Clare13571710324,424
Cork City729172022,153
Cork County3938184289,083
Kerry162239530,830
Limerick City5719213017,669
Limerick County2649168124,710
Tipperary14631310131,160
Waterford City6114232011,088
Waterford County2052206214,842
Galway City2039354215,178
Galway County765197337,953
Leitrim167171057,365
Mayo371168225,903
Roscommon470149311,746
Sligo163238614,999
Cavan967137514,328
Donegal078116429,562
Monaghan97013539,260
 
Total39361851966,293
Table 9 Main Space Heating Fuel by Period of Construction (2009-2021)
% of row  
Period of ConstructionFuel TypeTotal
Mains GasHeating OilElectricitySolid FuelLPG
1700-18992938239124,780
1900-19292939219154,639
1930-19494437109146,773
1950-1966473976172,698
1967-1977394956191,520
1978-1982365257159,064
1983-19933445127298,899
1994-199934382341108,053
2000-200441351931170,687
2005-200945311824156,575
2010-20145128171211,298
2015-2021403560071,307
       
Total39361851966,293
Table 10 Main Space Heating Fuel by Type of Dwelling (2009-2021)
% of row 
Dwelling TypeFuel TypeTotal
Mains GasHeating OilElectricitySolid FuelLPG
Apartment49544113,282
Ground-floor apartment466451251,008
Mid-floor apartment390600159,759
Top-floor apartment412551252,591
Basement Dwelling25106113279
Maisonette526391210,929
House177145333,667
Detached house15671062272,528
Semi-detached house48351051267,203
End of terrace house5922135174,752
Mid-terrace house61211261140,295
       
Total39361851966,293
Table 11 Average Floor Area by Period of Construction and Type of Dwelling (2009-2021)
m2
PeriodApartmentGround-floor apartmentMid-floor apartmentTop-floor apartmentBasement DwellingMaisonetteHouseDetached houseSemi-detached house End of terrace houseMid-terrace houseAll dwelling types
1700-18996853455650105147159149117106120
1900-19296448435341881201261239991101
1930-1949506145524773111121112858299
1950-19667163555765681171271168887105
1967-19776864605580661321411108685111
1978-1982646664568870138144998583112
1983-1993595855585571147151978381110
1994-19996663586866771541631038584112
2000-20047470697768881681791059792116
2005-200982727179879317219510710198114
2010-20148777717586100195221122117109148
2015-202180808186100109187198122116112126
 
All7667677160881481591089490113
Table 12 Average Primary Energy Use by Period of Construction and Type of Dwelling (2009-2021)
kWh/m2/year
PeriodApartmentGround-floor apartmentMid-floor apartmentTop-floor apartmentBasement DwellingMaisonetteHouseDetached houseSemi-detached house End of terrace houseMid-terrace houseAll dwelling types
1700-1899435410380471400459414400367398355390
1900-1929487414407477404453414407366403361393
1930-1949356345271408458441373384329342311347
1950-1966424313258374397299335343294319290313
1967-1977379308252350339300289289274274248278
1978-1982336276235285307299243244246240217242
1983-1993345293243286335269227226234239217231
1994-1999281265229267256241205200217237216214
2000-2004256230197229235201188185202205185196
2005-2009168185162188178160151154171168153163
2010-201420911799124132951009985908596
2015-20211035746556749575251514851
             
All222229177238293204232226213229231222
Table 13 Average Carbon Dioxide Emissions by Period of Construction and Type of Dwelling (2009-2021)
kgCO/m2/year
PeriodApartmentGround-floor apartmentMid-floor apartmentTop-floor apartmentBasement DwellingMaisonetteHouseDetached houseSemi-detached house End of terrace houseMid-terrace houseAll dwelling types
1700-189910292821058310610610388948396
1900-192911692881058610610710688958497
1930-19498378578899101969977787184
1950-19661016954808764858666716574
1967-1977916852747967737263635766
1978-1982816249617670616158555058
1983-1993836552638059565654554955
1994-1999665849575752504849534850
2000-2004584841485042464546444045
2005-2009363833393532363739363337
2010-2014472419243019232318181721
2015-2021201191013912111010910
  
All504937506344585649525252
Table 14 Dwellings with Multiple BERs (2009-2021)
                 % of total
Earliest YearLatest YearTotal
A1A2A3B1B2B3C1C2C3D1D2E1E2FG
A1000
A200000000
A300000000000
B1000000000001
B2000011000000002
B30000121000000005
C10000133100000008
C200001232100000011
C300000233210000012
D100000123321000014
D200000122222100013
E10000011112210009
E20000011111111007
F0000011111111108
G00000111111111110
  
Total01236141715121084322100
– No dwelling received this BER combination for the earliest and latest assessments
Table 15 BERs Weighted to National Level (2009-2021)
             % of row  
Dwelling TypeEnergy Rating Total
AB1B2B3C1C2C3D1D2E1E2FG
Apartment926911101011106447166,646
Detached house5138101212121165511685,847
Semi-detached house812611131314116555441,862
Terraced house612610111112118679259,837
               
Total6137101212121165681,554,192

Background Notes

Domestic Building Energy Ratings

Introduction

A Building Energy Rating (BER) is an indication of the energy performance of a dwelling (represented in units of kWh/m2/year). Actual energy performance will depend on how the occupants operate the dwelling. A BER is based on the characteristics of major components of the dwelling including: wall, roof and floor dimensions; window and door sizes and orientations, as well as the construction type and insulation, ventilation and air tightness features; the system for heat supply (including renewable energy), distribution, and control; and the type of lighting. The BER certificate indicates the annual primary energy usage and carbon dioxide emissions associated with the provision of space heating, water heating, ventilation, lighting, and associated pumps and fans. The energy use is calculated on the basis of a notional family with a standard pattern of occupancy - hence data in this release giving average primary energy use or carbon dioxide emissions are not based on actual data. A BER only covers electricity used for heating, lighting and ventilation with associated pumps and fans. Electricity used for cooking, refrigeration, laundry and other appliance use are not included.

Since 1st January 2009, a BER certificate and advisory report is compulsory for all homes being sold or offered for rent. A BER is also required for new dwellings that apply for planning permission on or after 1st January 2007. A BER certificate is required to avail of the grants for energy-efficiency improvements to the home that are provided under the Better Energy Homes scheme.

Access to Microdata 

Further information on the BER scheme (including links to a microdata research tool) is available on the Sustainable Energy Authority of Ireland website at http://www.seai.ie/BER/ 

Revisions 

The figures will be updated on a quarterly basis. While the changes to previous quarters will mainly relate to the most recent quarter, previous periods are also subject to revision mainly arising from some dwellings having another BER audit undertaken.

Coverage 

There are three types of BER Certificates. A New Dwelling – Provisional BER is required for a dwelling that is not yet built but is offered for sale off the plans. A New Dwelling – Final BER is required for a newly-built dwelling before it is occupied. This certificate is based on data collected in a site survey carried out by a registered BER Assessor as well as drawings and specifications for the completed dwelling. An Existing Dwelling BER is required for any existing dwelling that is offered for sale or to let. An existing dwelling is one that has previously been sold or occupied. This is based on data collected in a site survey carried out by a registered BER Assessor. Both the New Dwelling – Final BER and the Existing Dwelling BER certificates are valid for 10 years from the date of issue. They become invalid if material changes are made to the dwelling during that period. This release is an analysis of Final and Existing BER certificates. To ensure that all tables are consistent with each other, records that contain missing data in any of the main classification variables used in this release have been excluded e.g. missing response for county. Records with only the main space heating fuel or main water heating fuel information missing have been included except in tables using those variables. 

National representativeness  

There were 981,179 unique domestic BERs (one per dwelling) completed in the period 2009 to the end of December 2021. This compares with around 1.7 million occupied private households enumerated in the 2016 Census of Population. The 2016 Census of Population included questions on county of location of the dwelling, the period when the dwelling was built, and the type of dwelling. These questions can be used to weight the BER data to national level. Table 15 presents an initial weighting of BERs up to national level of non-vacant households using the 2016 Census of Population. The weights were calculated by dividing the number of non-vacant households in the Census by the number of unique BER households. In cases where a household had more than one BER carried out in the period 2009-2021 only the most recent BER was used. Around 8% of Census households were excluded because there were no BER households in the particular stratum e.g. detached houses in Dublin 1 that were constructed in the period 1919-1945. A stratum was classified as a unique combination of County (52 categories - Dublin postal districts were distinguished), period of construction (nine categories) and dwelling type (four categories). The BER contains more disaggregated dwelling types, e.g. mid-terrace house, but these had to be aggregated to correspond to the Census classification. 

In mid-2015 the Census and BER files were allocated Eircodes. This makes it possible to match both files at household level as postcodes are unique at letter-box level. This will create an opportunity to calculate weights in a more precise manner.

Non-domestic Buildings  

Since 1st July 2008, a BER Certificate is required for all new non-residential buildings and from 1st January 2009 for all public service buildings and for existing non-residential buildings. The CSO publishes a quarterly release analysing this file.

Definitions  

The BER rating scale is divided into categories from G (largest primary energy usage) to an A1 rating (lowest primary energy usage). The kilowatt-hour is the unit of energy used in Dwelling Energy Assessment Procedure (DEAP). The BER is measured in kWh per square metre of floor area of the dwelling per year (kWh/m2/year). The full range of categories is described in Table B. For the purposes of this release A1, A2, and A3 have been combined together because of the small number of Certificates in these categories. 

Table B: Building Energy Rating Categories 

Category

kWh/m2/year

A1

≤ 25

A2

> 25

A3

> 50

B1

> 75

B2

> 100

B3

> 125

C1

> 150

C2

> 175

C3

> 200

D1

> 225

D2

> 260

E1

> 300

E2

> 340

F

> 380

G

> 450

 

County is where the dwelling is located. 

Type of dwelling is selected from one of the following: Detached house; Semi-detached house; End of Terrace house; Mid-terrace house; Ground-floor apartment; Mid-floor apartment; Top-floor apartment; Basement apartment; and Maisonette. Some audit reports did not specify the type of house or apartment. 

Year of construction is when the dwelling was originally built. 

The fuel used by the Main Space Heating system. The main space heating system heats the largest proportion of the dwelling. This proportion is calculated using a count of the habitable rooms. It often provides hot water as well as space heating. 

The fuel used by the Main Water Heating system. This category has similar fuel response options to the Main Space Heating system. 

The Total Internal Floor Area of the dwelling is the total area of exposed and semi-exposed floors. It excludes any unheated areas that are thermally separated from the dwelling. The total energy usage is divided by the dwelling floor area to determine the Building Energy Rating. 

Table Notes  

Table 1 presents the number of Final and Existing BERs published by month since January 2009. A household that has had BERs conducted in different years is included in each year. This table gives an overview of the number of BER assessments being performed and will inform the user of changes since the previous quarterly analysis. 

Tables 2-13 only include the latest BER published for each dwelling from January 2009 to December 2021; hence the total number of BER certificates is lower than the total in Table 1.

Table 2 shows the general impact of the age of the dwelling on the BER profile. It can be linked with changes to the Building Regulations that require new homes to be more energy efficient. 

Table 3 shows how the BER profile varies by type of dwelling. 

Tables 4-5 profile BERs by county and Dublin postal district. Table 4 is in county within province order. 

Tables 6-7 profile BERs by main space and water heating fuels respectively. Records with a missing response for main space heating fuel have been excluded from Tables 6 and 8-10. Similarly records with a missing response for main water heating fuel have been excluded from Table 7. 

Table 8 cross-classifies county by main space heating fuel. Mains gas is not generally available in some counties. Some counties use local heating fuels such as peat e.g. County Offaly. 

Tables 9-10 cross-classify main space heating fuel by period of construction and dwelling type. 

Tables 11-13 cross-classify the average floor area, average primary energy use and average carbon dioxide emissions by period of construction and the dwelling type. The latter is more precisely defined in recent years but in the earlier years more general descriptions such as House were in use. It is not possible to reclassify these to detached, semi-detached, end-of-terrace or mid-terraced house. The average primary energy use and average carbon dioxide figures are notional figures based on assumed energy use factors and occupancy.

Table 14 is an analysis of properties that had BER audits carried out in more than one year. The earliest and latest BER ratings are cross-classified to show trends in energy savings arising from insulation, retrofitting etc.

Table 15 is an analysis of BER properties after they have been weighted to 2016 Census  of Population level. It can be compared with the Total row profile in Table 2. See the entry under National representativeness for more details.

upArrowHide Background Notes