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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.

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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 1 2022

Table A: Main Space Heating Fuel by Period of Construction (2000-2022)
% of rownumber
Period of ConstructionMains GasHeating OilElectricityBER audits
2000-200441%35%19%172,430
2005-200945%31%18%158,605
2010-201451%29%17%11,515
2015-201947%5%48%51,932
2020-202219%1%80%23,412

80% of dwellings built in 2020-2022 used electricity for heating

Figure 1: Main Space Heating Fuel by Period of Construction (2000-2022)
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Electricity was the main space heating fuel used in 80% of the dwellings completed during 2020-2022 and with a Building Energy Rating (BER) audit. This was a substantial increase from 2015-2019 when 48% of dwellings with a BER audit used electricity. There was a contrasting trend for mains gas with 19% of 2020-2022 built dwellings using mains gas compared with 47% for dwellings built in 2015-2019. There was also a contrasting trend for heating oil with 1% of 2020-2022 built dwellings using heating oil compared with 5% for dwellings built in 2015-2019 (see Table A, Figure 1 and Table 9).

There were 22,493 BER audits reported in quarter one 2022 compared with 14,585 in quarter one 2021. This is an increase of 54% (see Information Note). January 2022 was 64% higher than January 2021. February 2022 was a similar 62% above February 2021. The number of completed BER audits in March 2022 was 42% above the number in March 2021. In the period 2009 to March 2022 nearly 1.2 million BER audits have been undertaken (see Table 1).

Dwellings built in 2015-2019 and 2020-2022 were considerably more energy efficient than those built in earlier periods with 97% and 99% respectively given an “A” rating compared with 33% 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 33% (see Table 4). Leitrim, Roscommon and Tipperary had the lowest proportion of combined “A” and “B” rating at 12%.

Dublin 18, with an average dwelling age of 18 years, had the highest proportion of combined “A” and “B” rating at 48% (see Table 5). The average age of dwellings in Dublin 15 that have had a BER audit done was also 18 years, but the combined "A" and "B" rating was much lower at 33% than in Dublin 18. The highest proportion of combined “F” and “G” rating was 25% for Dublin 7.

The average floor area of all dwellings with a BER audit was 113 square metres (see Table 11). This average size varied from 160 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, 7% 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
A79
B111
B233
B378
C11011
C21212
C31212
D11211
D21110
E166
E254
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
1700-19771519241931
1978-1999174134115
2000-2004012602052
2005-200913650921
2010-201433577200
2015-20199730000
2020-20229900000
Table 1 Domestic BER Certificates (2009-2022) 1
number
Period20092010201120122013201420152016201720182019202020212022Total
January4,1124,6918,5756,5326,9767,0116,5295,2645,6875,1755,5235,8843,7606,18381,902
February6,3345,6469,0386,3128,5307,5477,6676,8686,8156,5006,8907,6214,7917,76898,327
March8,7746,1708,9526,5188,2118,3877,2697,5447,6326,5197,2177,1756,0348,542104,944
April8,0665,4897,7824,4478,2988,7377,5927,3997,1427,0547,2461,9966,261 87,509
May7,9385,4768,8795,8828,6488,7297,7167,9568,1788,3968,3312,4527,784 96,365
June8,7365,8017,4704,8657,2658,2178,0017,4487,6907,5927,5695,7947,929 94,377
July8,7775,9517,2575,5367,1039,3977,6746,5627,1257,5108,3537,6088,083 96,936
August7,2626,4167,5305,0456,9748,1677,6477,0307,2497,1548,2276,8886,778 92,367
September7,4987,4208,8474,9658,2789,9208,3557,6647,9727,2308,4108,7728,169 103,500
October6,5828,3959,5596,6878,97110,7659,2217,9278,0568,31010,8018,3979,067 112,738
November6,95511,5949,6058,7929,59710,8898,4009,0088,3908,2606,1808,0678,843 114,580
December6,3217,9989,4646,3616,9297,7737,3056,0765,6795,7396,2596,4726,075 88,451
                
Total87,35581,047102,95871,94295,780105,53993,37686,74687,61585,43991,00677,12683,57422,4931,171,996
1 Includes all Certificates for Dwellings
Table 2 BERs by Period of Construction (2009-2022)
% of row 
Period of ConstructionEnergy Rating Total
AB1B2B3C1C2C3D1D2E1E2FG
1700-18991012335710910143625,714
1900-1929101234571099143656,389
1930-19491123567912910122447,543
1950-1966112356811141110121674,054
1967-19771114791115161098893,399
1978-19821114913151717964359,937
1983-1993111510131619178542100,298
1994-1999112612161919135431109,859
2000-200401291822201373210173,390
2005-200913112224179632110162,340
2010-20143328181142111000012,286
2015-20199721000000000055,774
2020-202299000000000025,473
               
Total913811121211106457996,456
– No dwelling received this BER rating for this period of construction
Table 3 BERs by Type of Dwelling (2009-2022)
% of row 
Dwelling TypeEnergy Rating Total
AB1B2B3C1C2C3D1D2E1E2FG
Apartment1412131279101066573,375
Ground-floor apartment71371011111213865654,781
Mid-floor apartment134101212121097432368,416
Top-floor apartment614810101012127551056,465
Basement Dwelling603275776108929317
Maisonette1127121311999433711,268
House12391214141211544833,354
Detached house723811121211106459278,063
Semi-detached house1212612141412105444271,583
End of terrace house131261112111110656776,195
Mid-terrace house813913121010106557142,639
               
Total913811121211106457996,456
Table 4 BERs by County (2009-2022)
% of row  
CountyEnergy Rating Average age
AB1B2B3C1C2C3D1D2E1E2FGTotal
Carlow7137131413139544713,22930
Dublin 01-241014810111111117556224,88837
Dublin County19248111211108433374,97127
Kildare19138121312118433444,37522
Kilkenny62381213121210645816,02735
Laois6139121413108555815,20430
Longford3227121312141065698,37230
Louth11239161411108534628,68631
Meath1913915151196333437,66623
Offaly512510121210107781013,09634
Westmeath31381013141310655917,82332
Wexford71261013141411645732,37830
Wicklow14137111111119644629,48132
Clare4126913141411755824,78933
Cork City32491212111211766722,26945
Cork County9241114121098544791,18634
Kerry52381112121311755831,41831
Limerick City51381314131311644618,24538
Limerick County51361113141312644824,93433
Tipperary312610121212117661131,61340
Waterford City71261314141411644511,32236
Waterford County82371212121311544615,13835
Galway City71261113151512654415,50825
Galway County61371113131210655838,51529
Leitrim2127121412119667127,48834
Mayo51259131413116561026,37833
Roscommon31261114141196561211,96134
Sligo42371012121212765815,20332
Cavan31310151511118545914,63029
Donegal41261315141210655830,22131
Monaghan7238121011121164589,44235
                
Total913811121211106457996,45633
Table 5 BERs by Dublin Postal District (2009-2022)
% of row  
Dublin Postal DistrictEnergy Rating Average age
AB1B2B3C1C2C3D1D2E1E2FGTotal
Dublin 1625791011121275588,92433
Dublin 21225791011121075465,27134
Dublin 3413689101012989129,14558
Dublin 45158810101313866711,31446
Dublin 5512681011141398859,31844
Dublin 661356781113979159,26660
Dublin 6W13126889111187885,50347
Dublin 720247109121299101512,46660
Dublin 85158991011128671015,31747
Dublin 9131378991011877712,19044
Dublin 104026131512121076764,30447
Dublin 11102612121110109655412,75931
Dublin 125125791012139910911,27054
Dublin 132515910999844328,93825
Dublin 141135899101011866510,46338
Dublin 15181410141412118321123,90418
Dublin 1612149111312131154329,74828
Dublin 178161015191312842214,60225
Dublin 1818511141411876221111,71318
Dublin 208378889121396542,47033
Dublin 227015101415161574328,14328
Dublin 24141261214131311643117,86022
                
Total1014810111111117556224,88837
Table 6 BERs by Main Space Heating Fuel (2009-2022)
% of row  
Fuel TypeEnergy Rating Total
AB1B2B3C1C2C3D1D2E1E2FG
Mains Gas825111615121084332385,036
Bulk LPG2271821171285321113,415
Bottled LPG01410131412111154591,081
Heating Oil112712151514116555356,280
Electricity28222357101175512180,403
Coal00011411141419363,238
Smokeless Fuel000001412141216416,529
Peat0011410131317401,516
Wood Pellets & Chips2410201316118632221,628
Wood Logs432333510129101027638
Solid Multi-Fuel00000127131313153731,443
               
Total913812131212106557981,207
– No dwelling received this BER for this main space heating fuel type
Table 7 BERs by Main Water Heating Fuel (2009-2022)
             % of row 
Fuel TypeEnergy Rating Total
AB1B2B3C1C2C3D1D2E1E2FG
Mains Gas825111615121084332383,076
Bulk LPG2271821171285221113,361
Bottled LPG01410141412101164581,188
Heating Oil112712151514116555353,356
Electricity27222357101175514188,473
Coal0001112512141519283,100
Smokeless Fuel00012514151518315,561
Peat0011510131317381,539
Wood Pellets & Chips2411201316118632221,602
Wood Logs332433611121091024581
Solid Multi-Fuel00000127131414163129,370
               
Total913812131212106557981,207
– No dwelling received this BER for this main water heating fuel type
Table 8 Main Space Heating Fuel by County (2009-2022)
% of row    
CountyFuel Type 
Mains GasHeating OilElectricitySolid FuelLPGTotal
Carlow3444155113,221
Dublin 01-247152310215,546
Dublin County7411151072,231
Kildare4532192144,325
Kilkenny2849147215,962
Laois32431112115,169
Longford164201138,301
Louth5631102128,386
Meath4735152137,638
Offaly11541420112,970
Westmeath14541712317,771
Wexford168209232,250
Wicklow4136184129,154
Clare13571810324,733
Cork City729172022,116
Cork County3838184290,763
Kerry162239531,240
Limerick City5719213018,074
Limerick County2550168124,854
Tipperary1463139131,526
Waterford City6014232011,296
Waterford County1952216215,071
Galway City2039354215,395
Galway County765196338,405
Leitrim167181057,483
Mayo371168226,311
Roscommon470149311,956
Sligo163238615,166
Cavan966137514,543
Donegal078116429,950
Monaghan97013539,401
 
Total39361851981,207
Table 9 Main Space Heating Fuel by Period of Construction (2009-2022)
% of row  
Period of ConstructionFuel TypeTotal
Mains GasHeating OilElectricitySolid FuelLPG
1700-18992938239125,146
1900-19292939229155,619
1930-19494337109147,414
1950-1966473976173,766
1967-1977404956192,721
1978-1982355257159,677
1983-19933445127299,796
1994-199934382341109,174
2000-200441351931172,430
2005-200945311824158,605
2010-20145129171211,515
2015-2019475480051,932
2020-2022191800023,412
       
Total39361851981,207
Table 10 Main Space Heating Fuel by Type of Dwelling (2009-2022)
% of row 
Dwelling TypeFuel TypeTotal
Mains GasHeating OilElectricitySolid FuelLPG
Apartment49544113,227
Ground-floor apartment466451251,803
Mid-floor apartment390600160,868
Top-floor apartment402551253,416
Basement Dwelling25106014282
Maisonette526391211,104
House177145333,338
Detached house15671062277,836
Semi-detached house48351051271,168
End of terrace house5922135175,958
Mid-terrace house60211361142,207
       
Total39361851981,207
Table 11 Average Floor Area by Period of Construction and Type of Dwelling (2009-2022)
m2
PeriodApartmentGround-floor apartmentMid-floor apartmentTop-floor apartmentBasement DwellingMaisonetteHouseDetached houseSemi-detached house End of terrace houseMid-terrace houseAll dwelling types
1700-18996953455650105147159149117106120
1900-19296448445340881201261239991101
1930-1949506045524473111122113858299
1950-19667163555765681171271168887106
1967-19776763605680661321411108685111
1978-1982646563568870138144998583112
1983-1993595855585570147151978381110
1994-19996662586866771541631038584112
2000-20047470697767881681791059792116
2005-200982727179879317219510710198114
2010-20149377717586100194222122116109149
2015-20198081838862110187200124119114130
2020-2022787784113110193119109106116
 
All7667677160881481601089491113  
– No data is available for this dwelling type and period of construction  
Table 12 Average Primary Energy Use by Period of Construction and Type of Dwelling (2009-2022)
kWh/m2/year
PeriodApartmentGround-floor apartmentMid-floor apartmentTop-floor apartmentBasement DwellingMaisonetteHouseDetached houseSemi-detached house End of terrace houseMid-terrace houseAll dwelling types
1700-1899437409379470397458415400367397354389
1900-1929487410400475401453414406364402360392
1930-1949356345271409457440373383327341310346
1950-1966424312258374397299335342293319289312
1967-1977382307252351339301289288273273248278
1978-1982331276235285307296243243246240217242
1983-1993345292242285335270227225233238217230
1994-1999281265229266256240205199216237216213
2000-2004256230197228234200188184201205184196
2005-2009169185162188178160151153170168153163
2010-201423911799124132951019985908596
2015-201910360475715153575553545054
2020-202251444949424344454244
             
All223227175237289203232224212228230221
– No data is available for this dwelling type and period of construction
Table 13 Average Carbon Dioxide Emissions by Period of Construction and Type of Dwelling (2009-2022)
kgCO/m2/year
PeriodApartmentGround-floor apartmentMid-floor apartmentTop-floor apartmentBasement DwellingMaisonetteHouseDetached houseSemi-detached house End of terrace houseMid-terrace houseAll dwelling types
1700-189910292821048310610610388948396
1900-192911691861048610610710588958396
1930-19498378578898101969877787184
1950-19661016954808764858666716573
1967-1977916852757967737162635766
1978-1982806249617670616158555058
1983-1993836552638059565654544955
1994-1999655749575752504849534849
2000-2004584841485041464446443945
2005-2009363833383532363639363336
2010-2014552419243019232318181721
2015-201920119112910121110101011
2020-202210899899989
  
All504836506243585549515252
– No data is available for this dwelling type and period of construction
Table 14 Dwellings with Multiple BERs (2009-2022)
                 % of total
Earliest YearLatest YearTotal
A1A2A3B1B2B3C1C2C3D1D2E1E2FG
A1000
A200000000
A300000000000
B1000000000001
B2000011000000002
B30000121000000005
C10000133100000008
C200001232100000011
C300000233210000012
D100000123321000014
D200000112222100013
E10000011112210009
E20000011111111007
F0000011111111108
G00000111111111110
  
Total01236141715121084322100
– No dwelling received this BER combination for the earliest and latest assessments
Table 15 BERs Weighted to National Level (2009-2022)
             % of row  
Dwelling TypeEnergy Rating Total
AB1B2B3C1C2C3D1D2E1E2FG
Apartment1026911101011106447166,706
Detached house5238101212111065511685,728
Semi-detached house812611131313116555441,896
Terraced house712610111112118679260,007
               
Total7137101212121165681,554,336

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 996,456 unique domestic BERs (one per dwelling) completed in the period 2009 to the end of March 2022. 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 2009-2022 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 March 2022; 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.

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